ACTING STATE ENTOMOLOGIST. 
IT 
described that — no matter what scientific name we may decide to give it — it can never hereafter be 
mistaken for any other species. So much for this entomological riddle, to solve which with certainty 
would require a Guessing-machine of 1,000 Yankee power. 
In the perfect Beetle state the Grape Curculio will not be easily identified by the 
inexperienced in such matters, owing to the obscureness of its coloring, the absence of 
any conspicuous markings, and the fact that many perfectly distinct species — several 
of which, however, have a characteristic white scutel — resemble it strongly at first 
sight. But almost all of these last, though they have the same general appearance as 
the Grape Curculio, yet belong to different genera, the described North American 
species of the genus ( Oceliodes) being very few in number. Hence our species may be 
recognized with tolerable certainty by a remarkable character, peculiar to the genus 
(Ccdiodes) and not found in the allied genera (Phytobius, Ccuthorhynchus , Mononychus , 
Copturus , &c.,) ; namely, the rectangular thorn or tooth on the upper and outer edge 
of the four front shanks ( tibice ). For convenience’ sake, a greatly magnified figure of 
the front leg is given in figure la, where the reader will see at a glance the nature of 
this distinctive character. The bristles near the tip of the shank are in nature some¬ 
times obliquely erected, as shown in the engraving, sometimes depressed so as to be 
almost invisible except under a lens of very high power ; some of the legs in one and 
the same specimen often having the bristles erect, and others having them depressed. 
At first sight I supposed that these bristles were a sexual character. 
I have shown at great length, in my Papers on Willow-gall Insects, published in the 
Proceedings of the Entomological Society of Philadelphia , that, in the case of many larvte 
dwelling in the interior of vegetable substances, and deriving their food from such sub¬ 
stances, there are what may be called “ Guest-larvse,” belonging to distinct Species, and 
often to distinct Genera, to distinct Families, and even to distinct Orders of Insects. 
These last take advantage of the tenement prepared for them by the original inhabi¬ 
tant, who thus becomes their Host, and feed conjointly with him upon the same vege¬ 
table food. Technically, such insects are called “Inquilinesbut until I published on 
* 
the subject, entomologists were not aware how extensively this system prevails through¬ 
out the world of insects. From the “Parasites,” properly so called, these “Inqui¬ 
lines,” or “ Guests,” as we may call them in English, differ very widely, in that they 
are normally vegetable feeders, and only occasionally or incidentally destroy the life of 
their unfortunate Hosts : whereas the true “Parasites” feed exclusively upon the living 
bodies of their insect victims, and with a few exceptions live inside those living bodies, 
devouring the flesh piecemeal, although some few of them attach themselves externally 
to their prey, and gradually suck its life away like so many miniature leeches.* These 
last, by the way, must not be confounded with what I have called “ Cannibal” insects ; 
for each of these externally-feeding Parasitical larvse attaches itself to a single victim, 
which it never quits till it has attained its full growth; whereas the true Cannibal larva 
roams hither and thither, and before it attains its full growth will probably have de¬ 
voured dozens of victims. Hence, by a beautiful provision of nature, all the Parasitical 
larvse, whether internal or external feeders, are legless, because they have no occasion 
for locomotion; whereas all Cannibal larvae, inasmuch as they require to move from 
place to place, are furnished with legs, and are usually pretty strong on the leg besides. 
* I have ascertained that a number of larvae belonging to the Chalets family have this peculiar habit, 
and among the Ichneumon flies the genus Ophion has long been known to feed externally in the larva 
state. 
