OF INSECTS IN GENERAL. 
35 * 
their laft ftate of confinement, the butterflies are far in- 
ferior in voracity and in the powers of digeftion ; their 
food being then a thin liquid fubftance colle&ed from 
the leaves of plants, and devoured only in fmall quantity. 
The fame is the cafe with the different fpecies of lo- 
cufls ; feme of which in their larva ftate are the moft vo- 
racious of all animals, and defolate entire provinces. It 
is not till they arrive at their winged and more perfect 
form, that their depredations ceafe, and mankind are re- 
lieved from one of the heavieft calamities which fall up- 
on the human race in the fultry climates. It is by in- 
fers in their larva ftate that the roots of com are per- 
forated and devoured in more northerly countries. If 
the feafen prove cold and wet, they continue long under 
ground in that ftate of voracious vermine ; and the crop, 
in the mean time, is fo completely ate away, that in finite 
ioftances, fcarcely a tenth ftalk furvives their depreda- 
tions. In a more genial fpring, thele animals continue 
for a fttorter fpace in their aurelia ftate ; and the damage 
done by them is proportionably lefs ; their deftru&ive 
operations below ceafing as foon as they are enabled by 
their wings to rife into the air, and go in queft of fulle- 
nance in another element. 
Infefts, even in their winged ftate, all take food in 2 
greater or leffer quantity ; it feems, however, to be of *■ 
mare delicate nature, being often only the liquid l'ub- 
ftances that exude from vegetables. Some are faid, in- 
deed, to be fo {hort-lived, that they do not require any 
fuftenance, and have, as it is afferted, no mouths : Of 
this kind are the fphemera, the may-fly, and the gad- 
fly* This fact, however, would require a more accurate- 
degree of examination, and more l'arisfactory proof than 
2 has 
