INSECTS
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
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