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Golden-eyed Lace-winged Flies — Part 2

The eggs, instead of being deposited in rather large groups, as is the case with other species, are distributed almost invariably singly upon the leaves of trees, and rarely two are found together upon the same stalk. The young larva cuts off the upper end of the egg and on emerging crawls down the stalk and begins its search for food. Approaching the egg of the pear tree Psylla, for example, it immediately grasps it between its long curved mandibles and rapidly extracts the juicy contents. This is done with great celerity, the dry shell is cast aside, and the whole operation frequently takes less than a minute. The larva then eats anything in the shape of a living insect which comes its way. It is totally fearless, and attacks with eagerness insects much larger than itself. After ten days it becomes full grown (these observations were made in Maryland in July) and spins up in the curl of a leaf, or in any partial protection, constructing a delicate, slightly oval but nearly spherical silken cocoon, which is attached to the leaf by silken threads. This cocoon is very small in comparison with both the larva which spins it and the adult which emerges from it, and is less than an eighth of an inch long. The adult emerges in from ten to fourteen days, cutting off the upper end of the cocoon in a neat cap. It does not seem to be known whether this cap is partially cut by the larva, or whether, as with other Neuropterous insects, the pupa becomes active before transforming and cuts the cap through which the fly emerges.

The adult insect is peagreen in color, and when alive has brownish eyes with greenish reflections. It is very helpless, does not feed, and remains concealed in low grass during the day becoming active in the evening and depositing its eggs at that time. Helpless as it is, the disgusting odor which it emits when handled is probably its chief means of protection from its natural enemies.