112 
THE ORDER OP COLEODTERA. 
The antenme, in all the Trachelides are of nearly or the same width 
throughout, sometimes simple or filiform, sometimes serrate, and some- 
times pectinate or branched, especially in the males. The elongated 
coxae permit great freedom of motion to the legs ; and their frequently 
bright or diversified colors show that they live exposed to the light of 
the sun. Accordingly we find that in their matured state they are 
active diurnal insects, often frequenting plants and tlowers. 
We have designated the insects of this tribe as parasitic beetles , a 
title which preeminently, but not exclusively belongs to them. The 
term parasite literally means one who sits at the table of another, and 
lives at his expense, and is now very commonly applied to those insects 
which either inhabit the nests of other insects and subsist upon the food 
prepared by them, or which infest the bodies of other insects, feeding 
upon their substance, and ultimately causing their death. This para- 
sitism is found to be very extensive in the insect world, and to consti- 
tute one of the most efficient agencies by which the excessive increase of 
many kinds of insects is kept in check. The great majority of parasitic 
insects is found in the order of Ilymenoptera, where they comprise some 
of the most numerous of the families of insects. In the order of Ooleop- 
tera the parasitic species are comparatively few, and outside of the pres- 
ent tribe, are mostly limited to a small number of minute species in the 
families Staphylinidae, Pselaphkke and Scydimenid®. The parasitic 
character is therefore the more distinctive of the present tribe, most of. 
the families of which are parasitic in their larva state; though it ispret 
ty well determined that a few of them are lignivorous, and the larvae 
of some of the families are but little known. The Lagriid® aud Anthi- 
cidse, from certain observations which have been made upon them, are 
supposed to be carnivorous, andLatreille considered the latter to be par- 
asitic. The lihipiphorid®, Stylophidse, and Meloidie, including the sub- 
family of iloriides, are known to be parasitic. The lame of the Pyro- 
chroidse and Mordellkke are found in wood, upon which, therefore, they 
are supposed to feed. Mr. Riley has found the Mordella 8-punctata, 
and its larvae, (Fig. 50) in very rotten oak stumps, and he states there 
can be no doubt of its lignivorous habits, as he has found the lame in 
their own burrows, extending through the wood in all directions. He 
has likewise bred a smaller species from the green stems of ambrosia, 
and other herbacious plants. In a strict classification according to the 
habits, therefore, the Pyroehrouhe and Mordellkke would require to be 
separated from the parasitic families, but there appear to be no organic 
characters which these two families possess in common, which author- 
izes us in placing them in a tribe by themselves. 
It is one of the many remarkable facts in the natural history of insects 
that the same species often differs greatly in its habits and the nature of 
its food, in the different stages of its existence. We have had occasion 
