18 
FIRST ANNUAL REPORT OF THE 
In two words — to return to our new friends, the Guest-larvae — the difference between 
the Guest-larvae on the one hand and the Parisitical larvae and Cannibal larvae on the 
other hand, is pretty nearly that between an American burglar on the one hand and a 
Polynesian cannibal on the other hand. The insect Guest and the human burglar desire 
the goods of their victims, and do not usually take their lives, unless, for the object that 
they have in view, it is necessary or convenient to do so. On the other hand, the insect 
Parasite, and the insect Cannibal and the human cannibal desire the bodies of their 
victims as food for themselves, and are necessarily obliged to slay, because it is only by 
indicting death upon others that they can satiate their own carnivorous appetites. 
In the case of the Grape Curculio, as in many other such cases, there is more than one 
species of Guests sponging upon a single Host. I find that two very distinct larvae — 
one of them belonging to the same Order as the Curculio, (the Coleoptera or Beetles,) 
but to a very widely distinct Family, the other to an entirely different Order, (the Dip- 
tera or Two-winged Flies) — occupy the grapes after they have been tenanted by the 
Curculio, and derive their subsistence therefrom. Whether these spongers upon the 
fruits of other Bugs’ labors dwell as co-tenants with them in the larva state, I do not 
know. Perhaps they do not; at all events they do not do so for any considerable time. 
But most certainly the eggs, from which the intruding Guests spring, must be depos¬ 
ited in the infested grape by the mother-insect before the larva of the Curculio leaves 
it; for my infested grapes contained the Curculio larvae when I received them from Ohio, 
and were thereafter isolated in a closed vase, to which the mother of the Guest-larvae 
could gain no possible access. As one species of these Guests arrived at the perfect 
state about 6 weeks, and the other about 11 weeks after the Host, it is likely enough 
that the eggs of both of them w'ere deposited, in the wounded grape, not very long 
before the larva of the Grape Curculio was ready to descend to the earth and leave a 
clear stage for the operations of his successors; and that consequently these eggs did not 
hatch out till about the time that the spoiled grape was vacated by its original tenant. 
The former of the two Guests just now referred to is the Twin-spotted Nitidula ( Stel- 
idota geminata , Say) —a flatfish oval beetle, of an obscure brown color with dull yellow 
markings, and rather less than one-tenth of an inch long. It belongs to a somewhat 
extensive group (the Nitidula family), all of which feed in the larva state upon decaying 
animal or vegetable substances, and several of which may be often met With in decay¬ 
ing cheese, old half-picked bones, old sheep-pelts, &c. Of this insect, from some 50 
infested grapes, I bred Oct. 12tli — 20th no less than 33 specimens. So that manifestly 
their occurring in such grapes was not a mere casual phenomenon, but part of the reg¬ 
ularly pre-ordained system of Nature. Nature, indeed, in whatever direction we turn 
our eyes, is always economizing and utilizing what would otherwise be uselessly 
expended, and she cries aloud everywhere to those who know how to interpret her 
sacred mysteries, that nothing shall go to waste, nothing be lost, nothing be created in 
vain, whether in the animal or in the vegetable kingdom ; and that even death and 
decay and corruption shall, by her holy alchemy be transmuted everywhere, in the most 
bountiful profusion, into life and health and happiness. 
The second of the two Guests is a species of Midge, belonging to the genus Sciara and 
to the same group of Two-winged Flies as the notorious Wheat Midge, commonly 
known in Illinois as “the Red Weevil,” ( Cecidomyia tritici , Kirby), and the equally 
notorious Hessian Fly ( Cecidomyia destructor , Say). We may call it in English “the 
Grape Midge.” It is a small, slender, long-legged, blackish Fly, measuring to the tips 
of its wings about one-tenth of an inch, and with no conspicuous markings whatever. 
