Insects, Their Ways and Means of Living/Chapter II
Chapter II
The Grasshopper's Cousins
Nature's tendency is to produce groups rather than individuals. Any animal you can think of resembles in some way another animal or a number of other animnals. An insect resembles on the one hand a shrimp or a crab, and on the other a centipede or a spider. Resemblances amnong animnals are either superficial or fundamnental. For example, a whale or a porpoise resembles a fish and lives the life of a fish, but has the skeleton and other organs of land-inhabiting mammals. Therefore, notwithstanding their form and aquatic habits, whales and porpoises are classed as mammals and not as fishes.
When resemnblances between animals are of a fundamental nature, we believe that they represent actual blood relationships carried down from some far-distant common ancestor; but the determination of relationships between animals is not always an easy matter, because it is often difficult to know what are fundamental characters and what are superficial ones. It is a part of the work of zoologists, however, to investigate closely the structure of all animnals and to establish their true relationships. The ideas of relationship which the zoologist deduces from his studies of the structure of animals are expressed in his classification of them. The primnary divisions of the Animal Kingdom, which is generally likened to a tree, are called branches, or phyla (singular, phylum).
The insects, the centipedes, the spiders, and the shrimps, crayfish, lobsters, crabs, and other such creatures belong to the phylum Arthropoda. The name of this phylumn means "jointed-legs"; but, since many other animals have jointed legs, the name is not distinctive, except in that the legs of the arthropods are particularly jointed, each being composed of a series of pieces that bend upon each other in different directions. A name, however, as everybody knows, does not have to mean anything, for Mr. Smith
Fig. 14. Examples of four common classes of the Arthropoda
A, a crab (Crustacea). B, a spider (Arachnida). C, a centipede (Chilopoda).
D, a fly (Insecta, or Hexapoda)
may be a carpenter, and Mr. Carpenter a smith. A phylum is divided into classes, a class into orders, an order into families, a family into genera (singular, genus), and a genus is composed of species (the singular of which is also species). Species are hard to define, but they are what we ordinarily regard as the individual kinds of animals. Species are given double names, first the genus name, and second a specific name. For example, species of a common grasshopper genus named Melanoplus are distinguished as Melanoplus atlanus, Melanoplus femur-rubrum, Melanoplus differentialis, etc.
The insects belong to the class of the Arthropoda known as the Insecta, or Hexapoda. The word “insect,” as we have seen, means “in-cut,” while “hexapod” means “six-legged”—either term, then, doing very well for insects. The centipedes (Fig. 14 C) are the Myriapoda, or many-footed arthropods; the crabs (A), shrimps, lobsters, and others of their kind are the Crustacea, so called because most of them have hard shells; the spiders (B) are the Aracknida, named after that ancient Greek maiden so boastful of her spinning that Minerva turned her into a spider; but some arachnids, such as the scorpion, do not make webs.
The principal groups of insects are the orders. The grasshopper and its relatives constitute an order; the beetles are an order; the moths and butterflies are another order; the flies another; the wasps, bees, and ants still another. The grasshopper's order is called the Orthoptera, the word meaning “straight-wings,” but, again, not significant in all cases, though serving very well as a name. The order is a group of related families, and, in the Orthoptera, the grasshoppers, or locusts, make one family, the katydids another, the crickets a third; and all these insects, together with some others less familiar, may be said to be the grasshopper's cousins.
The orthopteran families are notable in many ways, some for the great size attained by their members, some for their remarkable forms, and some for musical talent. While this chapter will be devoted principally to the cousins of the grasshopper, a few things of interest may still be said about the grasshopper himself, in addition to what was given in the preceding chapter.
The Grasshopper Family
PLATE 1
A group of insects representing five common entomological Orders. Figure 2 is a damselfly, a kind of dragonfly, from New Guinea, Order Odonata; 4 is a grasshopper, and 6 a winged walking-stick of Japan, representing two families of Orthoptera; 1 and 8 are sucking bugs, Order Hemiptera, which includes also the aphids and the cicadas; 3 is a wasp from Paraguay, and 7 a solitary bee from Chile, Order Hymenoptera; 5 is a two-winged fly of the Order Diptera, from Japan. To entomologists these insects are known as follows: 1, Parypes laetus; 2, unidentified; 3, Pepsis completa; 4, Heliastus benjamini; 5, Pantophthalmus vittatus; 6, Micadina phluctanoides; 7, Caupolicana fulvicollis; 8, Margasus afzeli
length. The front wings are long and narrow (Fig. 63, W2), somewhat stiff, and of a leathery texture. They are laid over the thinner hind wings as a protection to the latter when the wings are folded over the back, and for this reason they are called the tegmina (singular, tegmen). The hind wings, when spread (W3), are seen to be large fans, each with many ribs, or veins, springing from the base. These wings are gliders rather than organs of flight. For most grasshoppers leap into the air by means of their strong hind legs and then sail off on the outspread wings as far as a weak fluttering of the latter will carry them. One of our common species, however, the Carolina locust (Frontispiece), is a strong flyer, and when
Fig. 15. A grasshopper, Chloealtis conspersa, that makes a sound by scraping its hind thighs over sharp-edged veins of its wings
A, the male grasshopper, showing the sound-making veins of the wing (b). B, inner surface of right hind leg, showing row of teeth (a) on the femur. C, several teeth of the femur (enlarged)
flushed flits away on an undulating course over the weeds and bushes and sometimes over the tops of small trees, but always swerving this way and that as if undecided where to alight. The great flights of the migratory locusts, described in the last chapter, are said to have been accomplished more by the winds than by the insects' strength of wing.
The locusts are distinguished by the possession of large organs on the sides of the body that appear to be designed for purposes of hearing. No insect, of course, has “ears” on its head; the grasshopper's supposed hearing organs are located on the base of the abdomen, one on each side (Fig. 63, Tm). Each consists of an oval depression of the body wall with a thin eardrumlike membrane, or tympanum, stretched over it. Air sacs lie against the inner face of the membrane, furnishing the equilibrium of air pressure necessary for free vibration in response to sound waves, and a complicated sensory apparatus is attached to its inner wall. Even with such large ears, however, attempts at making the grasshopper hear are never very succeasful; but its tympanal organs have the same structure as those of insects noted for their singing, which presumably, therefore, can hear their own sound productions.
Not many of the grasshoppers are musical. They are mostly sedate creatures that conceal their sentiments, if they have any. They are awake in the daytime and they sleep at night—commendable traits, but habits that seldom beget much in the way of artistic attainment. Yet a few of the grasshoppers make sounds that are perhaps music in their own ears. One such is an unpretentious little brown species (Fig. 15) about seven-eighths of an inch in length, marked by a large black spot on each side of the saddlelike shield that covers his back between the head and the wings. He has no other name than his scientific one of Chloealtis conspersa, for he is not widely known, since his music is of a very feeble sort. According to Scudder, his only notes resemble tsikk-tsikk-tsikk, repeated ten or twelve times in about three seconds in the sun, but at a slightly lower rate in the shade. Chloealtis is a fiddler and plays two instruments at once. The fiddles are his front wings, and the bows his hind legs. On the inner surface of each hind thigh, or femur, there is a row of minute teeth (Fig. 15 B, a), shown more magnified at C. When the thighs are rubbed over thc edges of the wings, their teeth scrape om a sharp-edged vein indicated by b. This produces the tsikk-sound just mentioned. Such notes contain little music to us, but Scudder says he has seen three males singing to one female at the same time. This female, however,
Fig. 16. A grasshopper, Mecostethus gracilis, that makes a sound by scraping sharp ridges on the inner surfaces of its hind thighs over toothed veins of the wings
A, the male grasshopper. B, left front wing; the rasping vein is the one marked I. C, a part of the rasping vein and its branches more enlarged, showing rows of teeth
Several other little grasshoppers fiddle after the manner of Chloealtis; but another, Mecostethus gracilis by name (Fig. 16), instead of having the rasping points on the legs, has on each fore wing one vein (B, I) and its branches provided with many small teeth, shown enlarged at C, upon which it scrapes a sharp ridge situated on the inner surface of the hind thigh.
In another group of grasshoppers there are certain species that make a noise as they fly, a crackling sound apparently produced in some way by the wings themselves. One of these, common through the Northern States, is known as the cracker locust, Circotettix verruculatus, on account of the loud snapping notes it emits. Several other members of the same genus are also cracklers, the noisiest being a western species called C. carlingianus. Scudder says he has had his attention drawn to this grasshopper “by its obstreperous crackle more than a quarter of a mile away. In the arid parts of the West it has a great fondness for rocky hillsides and the hot vicinity of abrupt cliffs in the full exposure to the sun, where its clattering rattle re-echoes from the walls.”
The Katydid Family
While the grasshoppers give examples of the more primitive attempts of insects at musical production and may be compared in this respect to the more primitive of human races, the katydids show the highest development of the art attained by insects. But, just as the accomplishments of one member of a human family may give prestige to all his relations and descendants, so the talent of one noted member of the katydid family has given notoriety to all his congeners, and his justly deserved name has come to be applied by the undiscriminating public to a whole tribe of singers of lesser or very mediocre talent whose only claim to the name of katydid is that of family relationship. In Europe the katydids are called simply the longhorn grasshoppers. In entomology the family is now the Tettigoniidae, though it had long been known as the Locustidae.
The katydids in general are most easily distinguished from the locusts, or shorthorn grasshoppers, by the great length of their antennae, those delicate, sensitive, tapering threads projecting from the forehead. But the two familles differ also in the number of joints in their feet, the grasshoppers having three (Fig. 17 A) and the katydids four (B). The grasshoppers place the entire foot on the ground, while the katydids ordinarily walk on the three basal segments only, carrying the long terminal joint elevated. The basal segments have pads on their under sides that adhere to any smooth surface such as that of a leaf, but the terminal joint bears a pair of claws used when it is necessary to grasp the edge of a support. The katydids are mostly creatures of the night and, though usually plain green in color, many of them have elegant
Fig. 17. Distinctive characters in the feet of the three families of singing Orthoptera
A, hind foot of a grasshopper. B, hind foot of a katydid. C, hind foot of a cricket
forms. Their attitudes and general comportment suggest much more refinement and a higher breeding than that of the heavy-bodied locusts. Though some members of the katydid family live in the fields and are very grasshopperlike or even cricketlike in form and manners, the characteristic species are seclusive inhabitants of shrubbery or trees. These are the true aristocrats of the Orthoptera.
An insect musician differs in many respects from a human musician, aside from that of being an insect instead of a human being. The insect artists are all instrumentalists; but since the poets and other ignorant people always speak of the "singing" of the crickets and katydids, it will be easier to use the language of the public than to correct it, especially since we have nothing better to offer than the word stridulating, a Latin derivative meaning "to creak." But words do not matter if we explain what we mean by them. It must be understood, therefore, that though we speak of the "songs" of insects, insects do not have true voices in the sense that "voice" is the production of sound by the breath playing on vocal cords. All the musical instruments of insects, it is true, are parts of their bodies; but they are to be likened to fiddles or drums, since, for the production of sound, they depend upon rasping and vibrating surfaces. The rasping surfaces are usually, as in the instruments of the grasshoppers (Figs. 15, 16), parts of the legs and the wings. The sound may be intensified, as in the body of a stringed instrument, by special resonating
Fig. 18. The front wings, or tegmina, of a meadow grasshopper, Orchelimum laticauda, illustrating the sound-making organs typical of the katydid family
A, left front wing and basal part of right wing of male, showing the four main veins: subcosta (Sc), radius (R), media (M), and cubitus (Cu); also the enlarged basal vibrating area, or tympanum (Tm), of each wing, the thick file vein (fv) on the left, and the scraper (s) on the right
B, lower surface of base of left wing of male, showing the file (f) on under side of the file vein (A, fv)
C, right front wing of female, which has no sound-making organs, showing simple normal venation
areas, sometimes on the wings, sometimes on the body. The cicadas, a group of musical insects to be described in a special chapter, have large drumheads in the wall of the body with which they produce their shrill music. They do not beat these drums, but cause them to vibrate by muscles in the body. The musical members of the insect families are in nearly all cases the males, and it is usually supposed that they give their concerts for the purpose of engaging the females, but that this is so in all cases we can not be certain.
The musical instruments of the katydids are quite different from those of the grasshoppers, being situated on the overlapping bases of the front wings, or tegmina. On this account the front wings of the males are always different from those of the females, the latter retaining the usual or primitive structure. The right wing of a female in one of the more grasshopperlike species, Orchelimum laticauda (Fig. 30), is shown at C of Figure 18. The wing is traversed by four principal veins springing from the base.
Fig. 19. Wings, sound-making organs, and the "ears" of a conehead grasshopper, Neoconocephalus ensiger, a member of the katydid familyA, B, right and left wings, showing the scraper (s) on the right, and the file vein (fv) on the left. C, under surface of the file vein, showing the file (f). D, front leg, showing slits (e) on the tibia opening into pockets containing the hearing organs (fig. 20 A)
The one nearest the inner edge is called the cubitus (Cu) and the space between it and this margin of the wing is filled with a network of small veins having no particular arrangement. In the wings of the male, however, shown at A of the same figure, this inner basal field is much enlarged and consists of a thin, crisp membrane (Tm), braced by a number of veins branching from the cubitus (Cu). One of these (fv), running crosswise through the membrane, is very thick on the left wing, and when the wing is turned over (B) it is seen to have a close series of small cross-ridges on its under surface which convert it into a veritable file (f). On the right wing this same vein is much more slender and its file is very weak, but on the basal angle of this wing there is a stiff ridge (s) not developed on the other. The katydids always fold the wings with the left overlapping the right, and in this position the file of the former lies above the ridge (s) of the latter. If now the wings are moved sidewise, the file grating on the ridge or scraper causes a rasping sound, and this is the way the katydid makes the notes of its music. The tone and w)lume of the sound, however, are probably in large part produced by the vibration of the thin basal membranes of the wings, which are called the tympana (Tm).
The instruments of different players differ somewhat in the details of their structure. There are variations in the form and size of the file and the scraper on the wings of different species, and differences in the veins supporting the tympanal areas, as shown in the drawings of these parts from a conehead (Fig. 27) given at A, B, and C, of Figure 19. In the true katydid, the greatest singer of the family, the file, the scraper, the tympana, and the wings themselves (Fig. 26) are all very highly developed to form an instrument of great efficiencv. But, in general, the instruments of different species do not differ nearly so much as do the notes produced from them by their owners. An endless number of tunes may be played upon the same fiddle. With the insects each musician knows only one tune, or a few simple variations of it, and this he has inherited from his ancestors along with a knowledge of how to play it on his inherited instrument. The stridulating organs are not functionally developed until maturity, and then the insect forthwith plays his native air. He never disturbs the neighbors with doleful notes while learning.
Very curiously, none of the katydids nor any member of their family has the earlike organs on the sides of the body possessed by the locusts. What are commonly supposed to be their organs of hearing are located in their front legs, as are the similar organs of the crickets. Two vertical slits on the upper parts of the shins, or tibiae (Fig. 19 D, e), open each into a small pocket (Fig. 20 A, E) with a tympanumlike membrane (Tm) stretched across its inner wall. Between the membranes are air cavities (Tra) and a complicated sensory receptive apparatus (B) connected by a nerve through the basal part of the leg with the central nervous system.
There are several groups of katydids, classed as subfamilies.
Fig. 20. The probable auditory organ of the front leg of Decticus, a member of the katydid family. (Simplified from Schwabe)
A, cross-section of the leg through the auditory organ, showing the ear slits (e, e) leading into the large ear cavities (E, E) with the tympana (Tm, Tm) on their inner faces. Between the tympana are two tracheae (Tra, Tra) dividing the leg cavity into an upper and a lower channel (BC, BC). The sensory apparatus forms a crest on the outer surface of the inner trachea, each element consisting of a cap cell (CCl), an enveloping cell (ECl) containing a sense rod (Sco), and a sense cell (SCl). Ct, the thick cuticula forming the hard wall of the leg
B, surface view of the sensory organ, showing the elements graded in size from above downward. The sense cells (SCl) are attached to the nerve (Nv) along the inner side of the leg
families. A subfamily name ends in inae to distinguish it from a family name, which, after the Latin fashion, terminates in idae.
THE ROUND-HEADED KATYDIDS
The members of this first group of the katydid family are characterized by having large wings and a smooth round forehead. They compose the subfamily Phaneropterinae, which includes species that attain the acme of grace, elegance, and refinement to be round in the entire orthopteran order. Nearly all the round-headed katydids are musical to some degree, but their productions are not
Fig. 21. A bush katydid, Scudderia furcata
Upper figure, a male; lower, a female in the act of cleaning a hind foot
of a high order. On the other hand, though their notes are in a high key, they are usually not loud and not of the kind that keep you awake at night.
Among this group are the bush katydids, the species of which are of medium size with slenderer wings than the others, and are comprised in the genus usually known as Scudderia but also called Phaneroptera. They have acquired the name of bush katydids because they are usually found on low shrubbery, particularly along the edges of moist meadows, though they inhabit other places, too, and their notes are often heard at night about the house. Our commonest species, and one that occurs over most of the United States, is the fork-tailed bush katydid (Scudderia furcata). Figure 21 shows a male and a female, the female in the act of cleaning the pads on one of her hind feet. The katydids are all very particular about keeping their feet clean, for it is quite essential to have their adhesive pads always in perfect working order; but they are so continually stopping whatever they may be doing to lick one foot or another, like a dog scratching fleas, that it looks more like an ingrown habit with them than a necessary act of cleanliness. The fork-tailed katydid is an unpretentious singer and has only one note, a high-pitched zeep reiterated several times in succession. But it does not repeat the series continuously, as most other singers do, and its music is likely to be lost to human ears in the general din from the jazzing bands of crickets. Yet occasionally its sort zeep, zeep, zeep may be heard from a near-by bush or from the lower branches of a tree.
The notes of other species have been described as zikk, zikk, zikk, or zeet, zeet, zeet, and some observers have recorded two notes for the same species. Thus Scudder says that the day notes and the night notes of Scudderia curvicauda differ considerably, the day note being represented by bzrwi, the night note, which is only hall as long as the other, by tchw. (With a little practice the reader should be able to give a good imitation of this katydid.) Scudder furthermore says that they change from the day note to the night note when a cloud passes over the sun as they are singing by day.
The genus Amblycorypha includes a group of species having wider wings than those of the bush katydids. Most of them are indifferent singers; but one, the oblong-winged katydid (A. oblongifolia), found over all the eastern half of the United States and southern Canada, is noted for its large size and dignified manners. A male (Fig. 22), kept by the writer one summer in a cage, never once lost his decorum by the humiliation of confinement. He lived apparently a natural and contented life, feeding on grape leaves and on ripe grapes, obtaining the pulp of the latter by gnawing holes through the skin. He was always sedate, always composed, his motions always slow and deliberate. In walking he carefully lifted each foot and brought the leg forward with a steady movement to the new position,
Fig. 22. The oblong-winged katydid, Amblycorypha oblongifolia, male
where the foot was carefully set down again. Only in the act of jumping did he ever make a quick movement of any sort. But his preparations for the leap were as calm and unhurried as his other acts: pointing the head upward, dipping the abdomen slowly downward, the two long hind legs bending up in a sharp inverted V on each side of the body, he would lead one to think he was deliberately preparing to sit down on a tack; but, all at once, a catch seems to be released somewhere as he suddenly springs upward into the leaves overhead at which he had taken such long and careful aim.
For a long time the aristocratic prisoner uttered no sound, but at last one evening he repeated three times a squeaking note resembling shriek with the s much aspirated and with a prolonged vibration on the ie. The next evening he played again, making at first a weak swish, swish, swish, with the s very sibilant and the i very vibratory. But after giving this as a prelude he began a shrill shrie-e-e-e-k, shrie-e-e-e-k, repeated six times, a loud sound described by Blatchley as a "creaking squawk—like the noise made by drawing a fine-toothed comb over a taut string."
The best-known members of the round-headed katydids, and perhaps of the whole family, are the angular-winged katydids (Fig. 23). These are large, maple-leaf green insects, much flattened from side to side, with the leaflike wings folded high over the back and abruptly bent on their upper margins, giving the creatures the humpbacked appearance from which they get their name of angular-winged katydids. The sloping surface of the back in front of the hump makes a large fiat triangle, plain in the female, but in the male corrugated and roughened by the veins of the musical apparatus.
There are two species of the angular-winged katydids in the United States, both belonging to the genus Microcentrum, one distinguished as the larger angular-winged katydid, M. rhombifolium, and the other as the smaller angular-winged katydid, M. retinerve. The females of the larger species (Fig. 23) , which is the more common one, reach a length of 2⅜ inches measured to the tips of the wings. They lay flat, oral eggs, stuck in rows overlapping like scales along the surface of some twig or on the edge of a leaf.
The angular-winged katydids are attracted to lights and may frequently be round on warm summer nights in the shrubbery about the house, or even on the porch and the screen doors. Members of the larger species usually make their presence known by their sort but high-pitched notes resembling tzeet uttered in short series, the first notes repeated rapidly, the others successively more slowly as the tone becomes also less sharp and piercing. The song may be written tzeet-tzeet-tzeet-tzeet-tzek-tzek-tzek-tzuk-tzuk, though the high key and shrill tones of the notes must be
Fig. 23. The larger angular-winged katydid, Microcentrum rhombifolium
Upper figure, a male; lower, a female
imagined. Riley describes the song as a series of raspings "as of a stiff quill drawn across a coarse file," and Allard says the notes "are sharp, snapping crepitations and sound like the slow snapping of the teeth of a stiff comb as some object is slowly drawn across it." He represents them thus: tek-ek-ek-ek-ek-ek-ek-ek-ek-ek-ek-tzip. But, however the song of Microcentrum is to be translated into English, it contains no suggestion of the notes of his famous cousin, the true katydid. Yet most people confuse the two species, or rather, hearing the one and seeing the other, they draw the obvious but erroneous conclusion that the one seen makes the sounds that are heard.
The smaller angular-winged katydid, Microcentrun? retinerve, is not so frequently seen as the other, but it has similar habits, and may be heard in the vines or shrubbery about the house at night, its song is a sharp zeet, zeet, zeet, the three syllables spaced as in ka-ty-did, and it is probable that many people mistake these notes for those of the true katydid.
"The angular-winged katydids are very gentle and unsuspicious creatures, allowing themselves to be picked up without any attempt at escaping. But they are good flyers, and when launched into the air sail about like miniature airplanes, with their large wings spread out straight on each side. When at test they have a comical habit of leaning over sidewise as if their fiat forms were top-heavy.
THE TRUE KATYDID
We now come to that artist who bears by right the name of "katydid," the insect (Fig. 24) known to science as Pterophylla camelli?folia and to the American public as the greatest of insect singers. Whether the katydid is really a musician or not, of course, depends upon the critic, but of his fame there can be no question, for his name is a household term as familiar as that of any of out own great artists, notwithstanding that there is no phonographic record of his music. To be sure, the cicada has more of a world-wide reputation than the katydid, for he has representatives in many lands, but he has not put his song into words the public can understand. And if simplicity be the test of true art, the song of the katydid stands the test, for nothing could be simpler than merely katy-did, or its easy variations, such as katy, katy-she-did, and katy-didn't.
Yet though the music of the katydid is known by ear or by reputation to almost every native American, few of us
Fig. 24. The true katydid, Pterophylla camellifolia, a male
are acquainted with the musician himself. This is because he almost invariably chooses the tops of the tallest trees for his stage and seldom descends from it. His lofty platform, moreover, is also his studio, his home, and his world, and the reporter who would have a personal interview must be efficient in tree climbing. Occasionally, though, it happens that a singer may be located in a smaller tree where access to him is easier or from which he may be dislodged by shaking. A specimen, secured in this way on August 12, lived till October 18 and furnished material for the following notes:
The physical characters of the captive and some of his attitudes are shown in Figures 24 and 25. His length is 1¾ inches from the forehead to the tips of the folded wings; the front legs are longer and thicker than in most other members of the family, while the hind legs are unusually short. The antennae, though, are extremely long, slender, and very delicate filaments, 213⁄16 inches in length.
Fig. 25. The katydid in various attitudes
A, usual position of a male while singing. B, attitude while running rapidly on a smooth surface. C, preparing to leap from a vertical surface. D, a male, seen from above, showing the stridulating area at the base of the wings. E, a female, showing the broad, flat, curved ovipositor
Between the bases of the antennae on the forehead there is a small conical projection, a physical character which separates the true katydid from the round-headed katydids and assigns him to the subfamily called the Pseudophyllinae, which includes, besides our species, many others that live mostly in the tropics. The rear margins of the wings are evenly rounded and their sides strongly bulged outward as if to cover a very plump body, but the space between them is mostly empty and probably forms a resonance chamber to give tone and volume to the sound produced by the stridulating parts. What might be the katydid's waistcoat, the part of the body exposed beneath the wings, has a row of prominent buttonlike swellings along the middle which rhythmically heave and sink with each respiratory movement. All the katydids are deep abdominal breathers.
The color of the katydid is plain green, with a conspicuous dark-brown triangle on the back covering the stridulating area of the wings. The tips of the mouth parts are vellowish. The eyes are of a pale transparent green, but each has a dark center which, like the pupil in a painting, is always fixed upon you from whatever angle you retreat. The movements of the captive individual are slow, though in the open he can run rather rapidly, and when he is in a hurry he often takes the rather absurd attitude shown at B of Figure 25, with the head down and the wings and body elevated. He never flies, and was never seen to spread his wings, but when making short leaps the wings are slightly fluttered, in preparing for a leap, if only one of a few inches or a foot, he makes very careful preparations, scrutinizing the proposed landing place long and closely, though perhaps he sees better in the dark and acts then with more agility. If the leap is to be made from a horizontal surface, he slowly crouches with the legs drawn together, assuming an attitude more familiar in a cat; but, if the jump is to be from a vertical support, he raises himself on his long front legs as at C of Figure 25, suggesting a camel browsing on the leaves of a tree. He sparingly eats leaves of oak and maple supplied to him in his cage, but appears to prefer fresh fruit and grapes, and relishes bread soaked in water. He drinks rather less than most orthopterons.
When the katydids are singing at night in the woods they appear to be most wary of disturbance, and often the voice of a person approaching or a crackle underfoot is sufficient to quiet a singer far overhead. The male in the cage never utters a note until he has been in darkness and quiet for a considerable time. But when he seems to be assured of solitude he starts his music, a sound of tremendous volume in a room, the tones incredibly harsh and rasping at close range, lacking entirely that melody they acquire with space and distance. It is only by extreme caution that the performer may be approached while singing, and even then the brief flash of a light is usually enough to silence those stentorian notes. Yet occasionally a glimpse may be had of the musician as he plays, most frequently standing head downward, the body braced rather stiffly on the legs, the front wings only slightly elevated, the tips of the hind wings projecting a little from between them, the abdomen depressed and breathing strongly, the long antennal threads waving about in all directions. Each syllable appears to be produced by a separate series of vibrations made by a rapid shuffling of the wings, the middle one being more hurried and the last more conclusively stressed, thus producing the sound so suggestive of ka-ty-did′, ka-ty-did′, which is repeated regularly about sixty times a minute on warm nights. Usually at the start, and often for some time, only two notes are uttered, ka-ty, as if the player bas difficulty in falling at once into the full swing of ka-ty-did.
The structure of the wings and the details of the stridulating parts are shown in Figure 26. The wings (A, B) fold vertically against the sides of the body, but their inner basal parts form wide, stiff, horizontal, triangular flaps that overlap, the left on top of the right. A thick, sunken, crosswise vein (fv) at the base of the left tympanum (Tm) is the file vein. It is shown from below at C where the broad, heavy file (f) is seen with its row of extremely coarse rasping ridges. The same vein on the right wing (B) is much smaller and has no file, but the inner basal angle of the tympanum is produced into a large lobe bearing a strong scraper (s) on its margin.
Fig. 26. Wings and the sound-making organs of the male katydid
A, left front wing, showing the greatly enlarged tympanal area (Tm), with its thick file vein (fv). B, base of right fore wing, with large scraper (s) on its inner angle, but with a very small file vein. C, under surface of file vein of left wing, showing the large, flat, coarsely-ribbed file (f)
The quality of the katydid's song seems to differ somewhat in different parts of the country. In the vicinity of Washington, the insects certainly say ka-ty-did as plainly as any insect could. Of course, the sound is more literally to be represented as kă ki-kǎk′, accented on the last syllable. When only two syllables are pronounced they are always the first two. Sometimes an individual in a band utters four syllables, "katy-she-did" or kǎ ki-kǎ-kǎk′, and again a whole band is heard singing in four notes with only an occasional singer giving three. It is said that in certain parts of the South the katydid is called a "cackle-jack," a name which, it must be admitted, is a very literal translation of the notes, but one lacking in sentiment and unbefitting an artist of such repute. In New England, the katydids heard by the writer in Connecticut and in the western part of Massachusetts uttered only two syllables much more commonly than three, and the sounds were extremely harsh and rasping, being a loud squă-wǎk′, squǎ-wǎk′, squă-wǎk′, the second syllable a little longer than the first. This is not the case with? those that say ka-ty. When there were three syllables the series was squǎ-wă-wăk′. If all New England katydids sing thus, it is not surprising that some New England writers have failed to see how the insects ever got the name of "katydid." Scudder says "their notes have a shocking lack of melody"; he represents the sound by xr, and records that the song is usually of only two syllables. "That is," he says, " they rasp their fore wings twice rather than thrice; these two notes are of equal (and extraordinary) emphasis, the latter about one-quarter longer than the former; or if three notes are given, the first and second are alike and a little shorter than the last."
When we listen to insects singing, the question always arises of why they sing, and we might as well admit that we do not know what motive impels them. It is probably an instinct with males to use their stridulating organs, but in many cases the tones emitted are clearly modified by the physical or emotional state of the player. The music seems in some way to be connected with the mating of the sexes, and the usual idea is that the sounds are attractive to the females. With many of the crickets, however, the real attraction that the male has for the female is a liquid exuded on his back, the song apparently being a mere advertisement of his wares. In any case the ecstacies of love and passion ascribed to male insects in connection with their music are probably more fanciful than real. The subject is an enchanted field wherein the scientist has most often weakened and wandered from the narrow path of observed facts, and where he bas indulged in a freedom of imagination permissible to a poet or to a newspaper reporter who wishes to enliven his chronicle of some event in the daily news, but which does not contribute anything substantia] to our knowledge of the truth.
The Coneheads
This group of the katydid family contains slender, grasshopperlike insects that have the forehead produced into a large cone and the face strongly receding, but which also possess long, slender antennae that distinguish them from the true or shorthorn grasshoppers. They constitute the subfamily Copiphorinae.
Fig. 27. A conehead grasshopper, or katydid, Neoconocephalus retusus
Upper figure, a male; lower, a female, with extremely long ovipositor
One of the commonest and most widely distributed of the larger coneheads is the species known as Neoconocephalus ensiger, or the "sword-bearing conehead." It is the female, however, that carries the sword; and it is not a sword either, but merely the immensely long egg-laying instrument properly called the ovipositor. The female conehead shown at B of Figure 27, has a similar organ, though she belongs to a species called retusus. The two species are very similar in all respects except for slight differences in the shape of the cone on the head. They look like slim, sharp-headed grasshoppers, 1½ to 1¾ inches in length, usually bright green in color, though sometimes brown.
The song of ensiger sounds like the noise of a miniature sewing machine, consisting merely of a long series of one note, tick, tick, tick, tick, etc., repeated indefinitely. Scudder says ensiger begins with a note like brw, then pauses an instant and immediately emits a rapid succession of sounds like chwi at the rate of about rive per second and continues them an unlimited time. McNeil represents the notes as zip, zip, zip; Davis expresses them as ik, ik, ik; and Allard hears them as tsip, tsip, tsip. The song of retusus (Fig. 27) is quite different. It consists of a long shrill whir which Rehn and Hebard describe as a continuous zeeeeeeeeee. The sound is not loud but is in a very high key and rises in pitch as the player gains speed in his wing movements, till to some human ears it becomes almost inaudible, though to others it is a plain and distinct screech.
Fig. 28. The robust conehead, Neoconocephalus robustus, in position of singing, with fore wings separated and somewhat elevated, the head downward
A large conehead and one with a much stronger instrument is the robust conehead, Neoconocephalus robustus (Fig. 28). He is one of the loudest singers of North American Orthoptera, his song being an intense, continuous buzz, somewhat resembling that of a cicada. A caged specimen singing in a room makes a deafening noise. The principal buzzing sound is accompanied by a lower, droning hum, the origin of which is not clear, but which is probably some secondary vibration of the wings. The player always sits head downward while performing, and the breathing motions of the abdomen are very deep and rapid. The robust conehead is an inhabitant of dry, sandy places along the Atlantic coast from Massachusetts to Virginia and, according to Blatchley, of similar places near the shores of Lake Michigan in Indiana. The writer made its acquaintance in Connecticut on the sandy flats of the Quinnipiac Valley, north of New Haven, where its shrill song may be heard on summer nights from long distances.
The Meadow Grasshoppers
Fig. 29. The common meadow grasshopper, Orchelimum vulgare, a member of the katydid family
Fig. 30. The handsome meadow grasshopper, Orchelimum laticauda
Upper figure, a male; lower, a female
the wings is marked by a brown spot at each corner. These little grasshoppers readily sing in confinement, both in the day and at night. Their music is very unpretentious and might easily be lost out of doors, consisting mostly of a sort, rustling buzz that lasts two or three seconds. Often the buzz is preceded or followed by a series of clicks made by a slower movement of the wings. Frequently the player opens the wings for the start of the song with a single click, then proceeds with the buzz, and finally closes with a few slow movements that produce the concluding series of clicks. But very commonly he gives only the buzz without prelude or staccato ending.
Another common member of the genus is the agile meadow grasshopper, Orchelimum agile. Its music is said to be a long zip, zip, zip, zee-e-e-e, with the zip syllable repeated many times. These two elements, the zip and zee, are characteristic of the songs of all the Orchelimums, some giving more stress to the first and others to the second, and
Fig. 31. The slender meadow grasshopper, Conocephalus fasciatus, one of the smallest members of the katydid family
Still smaller meadow grasshoppers belong to the genus Conocephalus, more commonly called Xiphidium. One of the most abundant species, the slender meadow grasshopper, C. fasciatus, is shown in Figure 31. It is less than an inch in length, the body green, the back of the thorax dark brown, the wings reddish-brown, and the back of the abdomen marked with a broad brown stripe. Allard says the song of this little meadow grasshopper may be expressed as tip, tip, tip, tseeeeeeeeeeeeee, but that the entire song is so faint as almost to escape the hearing. Piers describes it as ple-e-e-e-e-e, tzit, tzit, tzit, tzit. Like the song of Orchelimum vulgare it apparently may either begin or end with staccato notes.
THE SHIELD BEARERS
Another large group of the katydid family is the sub-family Decticinae, mostly cricketlike insects that live on the ground, but which have wings so short (Fig. 32) that they are poor musicians. They are called "shield bearers" because the large back plate of the first body segment is more or less prolonged like a shield over the back. Most of the species live in the western parts of the United States, where the individuals sometimes become so abundant as to form large and very destructive bands. One such species is the Mormon cricket, Anabrus simplex, and another is the Coulee cricket, Peranabrus scabricollis (Fig. 32), of the dry central region of the State of Washington. The females of these species are commonly wingless, but the males have short stubs of front wings that retain the stridulating organs and enable them to sing with a brisk chirp.
Still another large subfamily of the Tettigoniidae is the
Fig. 32. The Coulee cricket, Peranabrus scabricollis, male and female, an example of a cricketlike member of the katydid family
Rhadophorinae, including the insects known as "camel crickets." But these are all wingless, and therefore silent.
The Cricket Family
The chirp of the cricket is probably the most familiar note of all orthopteran music. But the only cricket commonly known to the public is the black field cricket, the lively chirper of our yards and gardens. His European cousin, the house cricket, is famous as the "cricket on the hearth" on account of his fondness for fireside warmth which so stimulates him that he must express his animation in song. This house cricket bas been known as Gryllus since the time of the ancient Greeks and Romans, and his name has been made the basis for the name of his family, the Gryllidae, for there are numerous other crickets, some that live in trees, some in shrubbery, some on the ground, and others in the earth.
The crickets have long slender antennae like those of the katydids, and also stridulating organs on the bases of the wings, and ears in their front legs. But they differ from the katydids in having only three joints in their feet (Fig. 17 C). The cricket's foot in this respect resembles the foot of the grasshopper (A), but usually differs from that of the grasshopper in having the basal joint smooth or hairy all around or with only one pad on the under surface. In most crickets, also, the second joint of the foot is very small.
Fig. 33. The wings of a tree cricket
A, right front wing of an immature female, showing normal arrangement of veins: Sc, subcosta; R, radius; M, media; Cu1, first branch of cubitus; Cu2, second branch of cubitus; 1A, first anal. (From Comstock and Needham)
B, front wing of an adult female of the narrow-winged tree cricket
C, front wing of an immature male, showing widening of inner half to form vibrating area, or tympanum, and modification of veins in this area. (From Comstock and Needham)
D, right front wing of adult male of the narrow-winged tree cricket; the second branch of cubitus (Cu2) becomes the curved file vein (fv); s, the scraper
Some crickets have large wings, some small wings, some no wings at all. The females are provided with long ovipositors for placing their eggs in twigs of trees or in the ground (Figs. 35, 36).
The musical or stridulating organs of the crickets are similar to those of the katydids, being formed from the veins of the basal parts of the front wings. But in the crickets the organs are equally developed on each wing, and it looks as if these insects could play with either wing uppermost. Yet most of them consistently keep the right wing on top and use the file of this wing and the scraper of the left, just the reverse of the custom among the katydids.
Fig. 34. A mole cricket, Neocurtilla hexadactyla
The front wings of male crickets are usually very broad and have the outer edges turned down in a wide flap that folds over the sides of the body when the wings are closed. The wings of the females are simpler and usually smaller. The differences between the front wings in the male and the female of one of the tree crickets (Fig. 37) is shown at B and D of Figure 33. The inner half of the wing (or the rear half when the wing is extended) is very large in the male (D) and has only a few veins, which brace or stiffen the wide membranous vibratory area or tympanum. The inner basal part, or anal area, of the male wing is also larger than in the female and contains a prominent vein () which makes a sharp curve toward the edge of the wing. This vein has the stridulating file on its under surface. The veins in the wing of an adult female (B) are comparatively simple, and those of a young female (A) are more so. But the complicated venation of the male wing has been developed from the simple type of the female, which is that common to insects in general. The wing of a young male (C) is not so different from that of a young female (A) but that the corresponding veins can be identified, as shown by the lettering. Taking next the wing of the adult male (D), it is an easy matter to determine which veins have been distorted to produce the stridulating apparatus. When the tree crickets sing they elevate the wings above the back like two broad fans (Figs. 37, 40) and move them sidewise so that the file of the right rubs over the scraper of the left.
THE MOLE CRICKETS
The mole crickets (Fig. 34) are solemn creatures of the earth. They lire like true moles in burrows underground, usually in wet fields or along streams. Their forefeet are broad and turned outward for digging like the front feet of moles. But the mole crickets differ from real moles in having wings, and sometimes they leave their burrows at night and fly about, being occasionally attracted to lights. Their front wings are short and lie flat on the back over the base of the abdomen, but the long hind wings are folded lengthwise over the back and project beyond the tip of the body.
Notwithstanding the gloomy nature of their habitat, the male mole crickets sing. Their music, however, is solemn and monotonous, being always a series of loud, deep-toned chirps, like churp, churp, churp, repeated very regularly about a hundred times a minute and continued indefinitely if the singer is not disturbed. Since the notes are most frequently heard coming from a marshy field or from the edge of a stream, they might be supposed to be those of a small frog. It is difficult to capture a mole cricket in the act of singing, for he is most likely standing at an opening in his burrow into which he retreats before he is discovered.
THE FIELD CRICKETS
This group of crickets includes Gryllus as its typical member, but entomologists give first place to a smaller brown cricket called Nemobius. There are numerous species of this genus, but a widely distributed one is N. vittatus, the striped ground cricket. This is a little cricket, about three-eighths of an inch in length, brownish in color, with three darker stripes on the abdomen, common in fields and dooryards (Fig. 35). In the fall the females lay their eggs in the ground with their slender ovipositors (D, E) and the eggs (F) hatch the following summer.
The song of the male Nemobius is a continuous twitter
Fig. 35. The striped ground cricket, Nemobius vittatus
A, B, females, distinguished by the long ovipositor. C, a male. D, a female in the act of thrusting her ovipositor into the ground. E, a female, with ovipositor full length in the ground, and extruding an egg from its tip. F, an egg in the ground
ing trill so faint that you must listen attentively to hear it. In singing the male raises his wings at an angle of about 45°. The stridulating vein is set with such fine ridges that they would seem incapable of producing even those whispering Nemobius notes. Most of themusical instruments of insects can be made to produce a swish, a creak, or a grating noise of some sort when handled with our clumsy fingers or with a pair of forceps, but only the skill of the living insect can bring from them the tones and the volume of sound they are capable of producing.
Our best-known cricket is Gryllus, the black cricket (Fig. 36), so common everywhere in fields and yards and occasionally entering houses. The true house cricket of Europe, Gryllus domesticus, bas become naturalized in this country anal occurs in small numbers through the Eastern States. But out common native species is Gryllus assimilis. Entomologists distinguish several varieties, though they are inclined to regard them all as belonging to the one species.
Mature individuals of Gryllus are particularly abundant in the fall; in southern New Egland they appear every year at this season by the millions, swarming everywhere, hopping across the country roads in such numbers that it is impossible to ride or walk without crushing them. Most of the females lay their eggs in September and October, depositing them singly in the ground (Fig. 36 D, E) in the same way that Nemobius does. These eggs hatch about the first of June the following year. But at this same time another group of individuals reaches maturity, a group that hatched in midsummer of the preceding year and passed the winter in an immature condition. The males of these begin singing at Washington during the last part of May, in Connecticut the first of June, and may be heard until the end of June. Then there is seldom any sound of Gryllus until the middle of August, when the males of the spring group begin to mature. From now on their notes become more and more common and by early fall they are to be heard almost continuously day and night until frost.
The notes of Gryllus are always vivacious, usually cheerful, sometimes angry in tone. They are merely chirps, and may be known from all others by a broken or vibratory sound. There is little music in them, but the player has enough conceit to make up for this lack. Two vigorous
Fig. 36. The common black cricket, Gryllus assimilis
A, a male with wings raised in the attitude of singing. B, a female with long ovipositor. C, young crickets recently hatched (enlarged about 2½ times). D, a female inserting her ovipositor in the ground. E, a female with ovipositor buried full length in the ground
The weather has much influence on the spirits of the males; their chirps are always loudest and their rivalry keenest when it is bright and warm. Setting their cage in the sun on cold days always started the two males at once to singing. Out of doors, though the crickets sing in all weather and at all hours, variations of their notes in tone and strength according to the temperature are very noticeable. This is not owing to any effect of humidity on their instruments, for the two belligerent males kept in the house never had the temper on cold and gloomy days that characterized their actions and their song on days that were warm and bright. This, in connection with the fact that their music is usually aimed at each other in a spirit clearly suggestive of vindictiveness and anger, is all good evidence that Grvllus sings to express himself and not to "charm the females." In fact, it is often hard to feel certain whether he is singing or swearing. If we could understand the words, we might be shocked at the awful language he is hurling at his rival. However, swearing is only a form of emotional expression, and singing is another. Gryllus, like an opera singer, simply expresses all his emotions in music, and, whether we can understand the words or not, we understand the sentiment.
At last one of the two caged rivals died; whether from natural causes or by foul means was never ascertained. He was alive early on the day of his demise but apparently weak, though still intact. In the middle of the afternoon, however, he lay on his back, his hind legs stretched out straight and stiff; only a few movements of the front legs showed that life was not yet quite extinct. One antenna was lacking and the upper lip and adjoining parts of the face were gone, evidently chewed off. But this is not necessarily evidence that death had followed violence, for, in cricketdom, violence more commonly follows death; that is, cannibalism is substituted for interment. A few days before, a dead female in the cage had been devoured quickly, all but the skull. After the death of this male, the remaining one no longer fiddled so often, nor with the same sharp challenging tone as before. Yet this could not be attributed to sadness; he had despised his rival and had clearly desired to be rid of him; his change was due rather to the lack of any special stimulus for expression.
The Tree Crickets
The unceasing ringing that always rises on summer evenings as soon as the shadows begin to darken, that shrill melody of sound that seems to come from nothing but from everywhere out of doors, is mostly the chorus of the tree crickets, the blend of notes from innumerable harpists playing unseen in the darkness. This sound must be the most familiar of all insect sounds, but the musicians themselves are but little known to the general public. And when one of them happens to come to the window or into the house and plays in solo, the sound is so surprisingly loud that the player is not suspected of being one of that band whose mingled notes are heard outside softened by distance and muffled by screens of foliage.
Out of doors the music of an individual cricket is so elusive that even when you think you have located the ex-
Fig. 37. The snowy tree cricket, Oecanthus niveus
The upper figures, males, the one on the right with fore wings raised vertically in attitude of singing; below, a female, with narrow wings folded close against the body
act bush or vine from which it comes the notes seem to shift and dodge. Surely, you think, the player must be under that leaf; but when you approach your ear to it, the sound as certainly comes from another over yonder; but here you are equally convinced that it comes from still another place farther off. Finally, though, it strikes the ear with such intensity that there can be no mistaking the source of its origin, and, right there in plain sight on a leaf sits a little, delicate, slim-legged, pale-green insect with hazy, transparent sails outspread above its back. But can such an insignificant creature be making such a deafening sound! It has required very cautious tactics to approach thus close without stopping the music, and it needs but a touch on stem or leaf to make it cease. But now those gauzy sails that before were a blurred vignette have acquired a definite outline, and a little more disturbance may cause them to be lowered and spread fiat on the creature's back. The music will not begin anew until you have passed a period of silent waiting. Then, suddenly, the lacy films go up, once more their outlines blur, and that intense scream again pierces your ear. In short, you are witnessing a private performance of the broad-winged tree cricket, Oecanthus latipennis.
But if you pay attention to the notes of other singers, you will observe that there is a variety of airs in the medley going on. Many notes are long trills like the one just identified, lasting indefinitely; but others are softer purring sounds, about two seconds in length, while still others are short beats repeated regularly a hundred or more times every minute. The last are the notes of the snowy tree cricket, Oecanthus niveus, so-called on account of his paleness. He is really green in color, but a green of such a very pale shade that he looks almost white in the dark. The male (Fig. 37) is a little longer than half an inch, his wings are wide and flat, overlapping when folded on the back, with the edges turned down against the sides of the body. The female is heavier-bodied than the male, but her wings are narrow, and when folded are furled along the back. She has a long ovipositor for inserting her eggs into the bark of trees.
The males of the snowy cricket reach maturity and begin to sing about the middle of July. The singer raises his wings vertically above the back and vibrates them sidewise so rapidly that they are momentarily blurred with each note. The sound is that treat, treat, treat, treat already described, repeated regularly, rhythmically, and monotonously all through the night. At the first of the season there may be about 125 beats every minute, but later, on hot nights, the strokes become more rapid and mount to 160 a minute. In the fall again the rate decreases on cool evenings to perhaps a hundred. And finally, at the end of the season, when the players are benumbed with cold, the
Fig. 38. Distinguishing marks on the basal segments of the antennae of common species of tree crickets
A, B, narrow-winged tree cricket, Oecanthus angustipennis. C, snowy tree cricket, niveus. D, four-spotted tree cricket, nigricornis quadripunctatus. E, black-horned tree cricket, nigricornis. F, broad-winged tree cricket, latipennis
notes become hoarse bleats repeated slowly and irregularly as if produced with pain and difficulty.
The several species of tree crickets belonging to the genus Oecanthus are similar in appearance, though the males differ somewhat in the width of the wings and some species are more or less diffused with a brownish color. But on their antennae most species bear distinctive marks (Fig. 38) by which they may be easily identified. The snowy cricket, for example, has a single oval spot of black on the under side of each of the two basal antennal joints (Fig. 38 C). Another, the narrow-winged tree cricket, has a spot on the second joint and a black J on the first (A, B). A third, the four-spotted cricket (D), has a dash and dot side by side on each joint. A fourth, the black-horned or striped tree cricket (E), has two spots on each joint more or less run together, or sometimes has the whole base of the antenna blackish, while the color may also spread over the fore parts of the body and, on some individuals, form
Fig. 39. Male and female of the narrow-winged tree cricket, Oecanthus angustipennis
The female is feeding on a liquid exuded from the back of the male, while the latter holds his fore wings in the attitude of singing. (Enlarged about 3 times)
stripes along the back. A fifth species, the broad-winged (F), has no marks on the antennae, which are uniformly brownish.
The narrow-winged tree cricket (Oecanthus angustipennis) is almost everywhere associated with the snowy, but its notes are very easily distinguished. They consist of slower, purring sounds, usually prolonged about two seconds, and separated by intervals of the same length, but as fall approaches they become slower and longer. Always they are sad in tone and sound far off.
The three other common tree crickets, the black-horned or striped cricket, Oecanthus nigricornis, the four-spotted, 
Fig. 40. A male of the broad-winged tree cricket, Oecanthus latipennis, with wings elevated in position of singing, seen from above and behind, showing the basin (B) on his back into which the liquid is exuded that attracts the female
O. nigricornis quadripunctatus, and the broad-winged, O. latipennis, are all trillers; that is, their music consists of a long, shrill whir kept up indefinitely. Of these the broad-winged cricket makes the loudest sound and the one predominant near Washington. The black-horned is the common triller farther north, and is particularly a daylight singer. In Connecticut his shrill note rings everywhere along the roadsides, on warm bright afternoons of September and October, as the player sits on leaf or twig fully exposed to the sun. At this season also, both the snowy and the narrow-winged sing by day but usually later in the afternoon and generally from more concealed places.
We should naturally like to know why these little creatures are such persistent singers and of what use their music is to them. Do the males really sing to charm and attract the females as is usually presumed? We do not know; but sometimes when a male is singing, a female approaches him from behind, noses about on his back, and soon finds there a deep basinlike cavity situated just behind the bases of the elevated wings. This basin contains a clear liquid which the female proceeds to lap up very eagerly,
Fig. 41. The back of the third thoracic segment of the broad-winged tree cricket, with its basin (B) that receives secretion from the glands (GI) inside the body
A male cricket with his front wings raised, seen from above and behind as he might look to a female, is shown in Figure 40. The basin (B) on his back is a deep cavity on the dorsal plate of the third thoracic segment. A pair of large branching glands (Fig. 41, Gl) within the body open just inside the rear lip of the basin, and these glands furnish the liquid that the female obtains.
There is another kind of tree cricket belonging to another genus, Neoxabia, called the two-spotted tree cricket, N. bipunctata, on account of two pairs of dark spots on the wings of the female. This cricket is larger than any of the species of Oecanthus and is of a pinkish brown color. It is widely distributed over the eastern hall of the United States, but is comparatively rare and seldom met with. Allard says its notes are low, deep, mellow trills continued for a few seconds and separated by short intervals, as are the notes of the narrow-winged Oecanthus, but that their tone more resembles that of the broad-winged.
THE BUSH CRICKETS
Fig. 42. The jumping bush cricket, Orocharis saltator
Upper figure, a male; lower, a female
cricket, Orocharis saltator (Fig. 42), who comes on the stage late in the season, about the middle of August, or shortly after. His notes are loud, clear, piping chirps with a rising inflection toward the end, suggestive of the notes of a small tree toad, and they at once strike the listener as something new and different in the insect program. The players, however, are at first very hard to locate, for they do not perform continuously—one note seems to come from here, a second from over there, and a third from a different angle, so that it is almost impossible to place any one of them. But after a week or so the crickets become more numerous and each player more persistent till soon their notes are the predominant sounds in the nightly concerts, standing out loud and clear against the whole tree-cricket chorus. As Riley says, this chirp "is so distinctive that when once studied it is never lost amid the louder racket of the katydids and other night choristers."
After the first of September it is not hard to locate one of the performers, and when discovered with a flashlight, he is found to be a medium-sized, brown, short-legged cricket, built somewhat on the style of Gryllus but smaller (Fig. 42). The male, however, while singing raises his wings straight up, after the manner of the tree crickets, and he too, carries a basin of liquid on his back much sought after by the female. In fact the liquid is so attractive to her that, at least in a cage, she is sometimes so persistent in her efforts to obtain it that the male is clearly annoyed and tries to avoid her. One male was observed to say very distinctly by his actions, as he repeatedly tried to escape the nibbling of a female, presumably his wife since she was taken with him when captured, "I do wish you would quit pestering me and let me sing!" Here is another piece of evidence suggesting that the male cricket sings to express his own emotions, whatever they may be, and not primarily to attract the female. But if, as in the case of the tree crickets, his music tells the female where she may find her favorite confection, and this in turn leads to matrimony, when the male is in the proper mood, it suggests a practical use and a reason for the stridulating apparatus and the song of the male insect.
Fig. 43. The common walking stick insect, Diapheromera femorata, of the eastern part of the United States. (Length 2½ inches)
Walking-Sticks and Leaf Insects
Talent often seems to run in families, or in related families, but it does not necessarily express itself in the same way. If the katydids and crickets are noted musicians, some of their relatives, belonging to the family Phasmidae, are incomparable mimics. Their mimicry, however, is not a conscious imitation, but is one bred in their bodily forms through a long line of ancestors.
Fig. 44. A gigantic spiny walking-stick insect, Eurycanthus horrida, from New Guinea. (Length 5½ inches)
If sometime in the woods you should chance to see a short, slender piece of twig suddenly come to life and slowly walk away on six slim legs, the marvel would not be a miracle, but a walking-stick insect (Fig. 43). These insects are fairly common in the eastern parts of the United States, but on account of their resemblance to twigs, and their habit of remaining perfectly quiet for a long time with the body pressed close to a branch of a tree, they are more frequently overlooked than seen. Sometimes, however, they occur locally in great numbers. It is supposed that the stick insects so closely resemble twigs for the purpose of protection from their enemies, but it has not been shown just what enemies they avoid by their elusive shape. The stick insects are more common in the South and in tropical countries, where some attain a remarkable length, one species from Africa, for example, being eleven inches long when full-grown. In New Guinea there lives a species that looks more like a small club than a stick, it being a large, heavy-bodied, spiny creature, nearly six inches in length and an inch in width through the thickest part of its body (Fig. 44).
Other members of the phasmid family have specialized on imitating leaves. These insects have wings in the adult stage, and, of course, the wings make it easier for them to take the form of leaves. One famous species that lives in the East Indies looks so much like two leaves stuck together that it is truly marvelous that an insect could be so fashioned (Fig. 45). The whole body is flat, and about three inches long, the bases of the legs are broad and irregularly notched, the abdomen is spread out almost as thin as a real leaf, and the leaflike wings are held close above it. Finally, the color, which is leaf-green or brown, gives the last touch necessary for complete dissimulation.
Fig. 45. A tropical leaf insect, Pulchriphyllium pulchrifolium, a member of the walking-stick family. (Length 3 inches)
The Mantids
It is often observed that genius may be perverted, or put to evil purposes. Here is a family of insects, the Mantidae, related to the grasshoppers, katydids, and crickets, the members of which are clever enough, but are deceitful and malicious.
The praying mantis, Stagmomantis carolina (Fig. 46), though he may go by the aliases of "rear-horse" and "soothsayer," gets his more common name from the prayerful attitude he commonly assumes when at rest. The long, necklike prothorax, supporting the small head, is elevated and the front legs are meekly folded. But if you examine closely one of these folded legs, you will see that the second and third parts are armed with suspicious-looking spikes, which are concealed when the two parts are closed upon each other. In truth, the mantis is an arch hypocrite, and his devotional attitude and meek looks betoken no humility of spirit. The spiny arms, so innocently folded upon the breast, are direful weapons held ready to strike as soon as some unsuspecting insect happens within their reach. Let a small grasshopper come near the posing saint: immediately a sly tilt of the head belies the suppliant manner, the crafty eyes leer upon the approaching insect, losing no detail of his movements. Then, suddenly, without warning, the praying mantis becomes a demon in action. With a nice calculation of distance, a swift movement, a snatch of the
Fig. 46. The praying mantis, Stagmomantis carolina, and remains of its last meal. (Length 2½ inches)
terrible clasps, the unlucky grasshopper is a doomed captive, as securely held as if a steel trap had closed upon his body. As the hapless creature kicks and wrestles, the jaws of the captor sink into the back of his head, evidently in search of the brain; and hardly do his weakening struggles cease before the victim is devoured. Legs, wings, and other fragments unsuitable to the taste of an epicure are thrown aside, when once more the mantis sinks into repose, piously folds his arms, and meekly awaits the chance arrival of the next course in his ever unfinished banquet of living fare.
Fig. 47. A mantis from Ecuador with a shieldlike extension of its back. (Length 3⅜ inches)
Some exotic species of mantids have the sides of the prothorax extended to form a wide shield (Fig. 47), beneath which the forelegs are folded and completely hidden. It is not clear what advantage they derive from this device, but it seems to be one more expression of deceit.
Of course, as we shall take occasion to observe later, goodness and badness are largely relativity. The mantis is an evil creature from the standpoint of a grasshopper, but he would be regarded as a benefactor by those who have a grudge against grasshoppers or against other insects that the mantis destroys. Hence, we must reckon the mantis as at least a beneficial insect relative to human welfare. A large species of mantis, introduced a few years ago into the eastern States from China, is now regarded as a valuable agricultural asset because of the number of harmful insects it destroys.
Fig. 48. Egg case of a mantis attached to a twig, Stagmomantis carolina
The mantids lay their eggs in large cases stuck to the twigs of trees (Fig. 48). The substance of which the case is made is similar to that with which the locusts inclose their eggs, and is exuded from the body of the female mantis when the eggs are laid. The young mantids are active little creatures, without wings but with long legs, and it is the fate of those unprotected green bugs, the aphids, or plant lice, that infest the leaves of almost all kinds of plants, to become the principal victims of their youthful appetites.