206 INSECTS INJURIOUS TO VEGETATION. 



LEPIDOPTERA. 



Caterpillars. — Butterflies. Skippers. — Hawk-Moths. .Sgerians or 

 Boring-Caterpillars. Glaucopidians. — Moths. — Spinners. Lithosians.— 

 Tiger-Moths. Ermine-Moths. Tussock-Moths. — Lackey-Moths. Lap- 

 pet-Moths. — Saturnians. — Ceratocampians. — Carpenter-Moths. — 



PsVCHIANS. NOTODONTIANS. — OwL-MoTHS. CuT-WoRMS. — GEOMETERS, 



OR Span- Worms, and Canker-Worms. — Delta-Moths. — Leaf-Rollers, 

 BuD-MoTHS. Fruit-Moths. — Bee-Moths. Corn-Moths. Clothes- 

 Moths. — Feather-winged-Moths. 



There are perhaps no insects which are so commonly and so 

 universally destructive as caterpillars ; they are inferior only to 

 locusts in voracity, and equal or exceed them in their powers of 

 increase, and in general are far more widely spread over vegeta- 

 tion. Caterpillars are the young of butterflies and of-moths; and 

 of these, five hundred species, which are natives of Massachu- 

 setts, are already known to me, and probably there are at least as 

 many more kinds to be discovered within the limits of this Com- 

 monwealth. As each female usually lays from two hundred to 

 five hundred eggs, one thousand different kinds of butterflies and 

 moths will produce, on an average, three hundred thousand cater- 

 pillars ; if one half of this number, when arrived at maturity, are 

 females, they will give forty-five milhons of caterpillars in the 

 second, and six thousand seven hundred and fifty millions in the 

 third generation. These data suffice to show that the actual num- 

 ber of these insects, existing at any one time, must be far beyond 

 the limits of calculation. The greater part of caterpillars subsist 

 on vegetable food, and especially on the leaves of plants ; hence 

 their injuries to vegetation are immense, and are too often forced 

 upon our notice. Some devour the solid wood of trees, some 

 live only in the pith of plants, and some confine themselves to 

 grains and seeds. Certain species attack our woollens and furs, 

 thereby doing us much injury ; even leather, meat, wax, flour, 

 and lard afford nourishment to particular kinds of caterpillars. 



Caterpillars vary greatly in form and appearance ; but, in gen- 

 eral, their bodies are more or less cylindrical, and composed of 

 twelve rings or segments, with a shelly head, and from ten to six- 



