30 
ORDER OR COLEOi’TERA. 
habits than any of the other orders of insects. Indeed this principle 
of classification is of value just in proportion as such diversity exists; 
and where it is very limited, as especially in the great order of Lepi- 
doptera, it ceases to be available, liven in classifying the Coleoptera 
upon this basis, and at the same time paying the necessary respect to 
structural considerations, we are sometimes compelled to place insects 
of similar food-habits in several different, and sometimes remote, tribes. 
The wood-boring beetles, for example, constitute three distinct tribes, 
designated as the saw-horned borers ( Buprcxtidw) ; the long-horned 
borers ( GerambycidccJ, and the short-horned borers fSooly tidal. J There 
are likewise four distinct families of fungus-beetles, found respectively 
in each of the four tarsal sections. But notwithstanding such instances 
as these, the Coleoptera admit of a very interesting, useful, and, in the 
main 
natural classification in accordance with the nature ot their food. 
As compared with the other orders of insects the Coleoptera are sur- 
passed only by the Lepidoptera in the extent of their injuries to culti- 
vated crops; and indeed they are so nearly equal to the latter in this 
respect, that there may be a doubt which takes the precedence; and it 
is true of either of these two orders, that, with the exception of the 
other, it includes a greater number of injurious species than all the 
other orders of insects combined. The great destructiveness ol the 
Lepidoptera is readily explained by the nature of their food, nearly 
all their larva-, commonly known as caterpillars, subsisting upon plant- 
food, and mostly in a fresh and growing state. The Coleoptera, on the 
contrary, embrace, in addition to the plant-eating species, extensive 
tribes of predacious and scavenger beetles, which are indirectly ol in- 
calculable benefit to mankind. 
In studying the bearing of scientific upon practical entomology , noth- 
ing perhaps is more important than to trace the connection ot the ex- 
ternal structure of insects with their habits, and especially with the 
nature of their food; since we are thus enabled, to a certain extent, to 
determine the habits of an insect by simply observing the form and 
structure of its Visible parts. We are able to lay down some general 
rules of this kind with respect to the Coleoptera, though most of them 
are subject to important exceptions. In order not to give too much 
space to this part of the subject, we will limit our observations to two 
of the most important and prominent organs— the antenna;, and the 
feet, or tarsi. 
All predaceous beetles have filiform antennae except the lady birds or 
( loccinellidae. 
All the scavenger beetles have strongly clavate or knobbed antenna;, 
except the short-winged scavengers or Staphylinid®, and these are only 
partial exceptions, as mauy ot them are known to be predaceous. 
