LICE
senses must be dull, indeed, if it is aphids that she wants. Do not lose sight of her, however, for her attitude bas changed; now she certainly bas her eye upon something that holds her attention, but the object is nothing other than one of those swollen parasitized aphids. Yet she excitedly runs up toit, feels it, grasps it, mounts upon it, examines it all over. Evidently she is satisfied. She dismounts, turns about, backs her abdomen against the
inflated mummy; now out comes the swordlike .',?,t/. ovipositor, and with a thrust it is sunken into the already parasitized aphid. Two mmu tes
later her business is ended, the ovipositor is withdrawn, once morè sheathed, and the insect is off and awav. This tiny creature is a hyperparasite, which is to say, a parasite of a para- site. In the act just wit- Fro. III. A parasitized larva of a lady- bird beetle, and one of the parasites The larva of the beetle has attached itself to a leaf preparatory to pupation, but has not changed to a pupa because of the parasites within it. Above, one of the parasites, which escaped from the beetle larva through a hole if cut in the skin of the latter
nessed she, too, has thrust an egg into the aphid, but the grub that will hatch from it will devour the parasitic occupant that is already in pos- session of the aphid's
skin. There are also parasites of hyperparasites, but the series does hOt go on "ad infinitum" as in the old rhyme, for the limitation of size must intervene.
