﻿OP THE STATE ENTOMOLOGIST. 89 



sively that it was the true or Spring species upon which the essay 

 was based. 



Extracts from the original Essay 07i the Canker-worm, by William Dandridge Peck, "pub- 

 lished in 1795. 



To cultivate a knowledo^e of insects, merely for their splendid pluraaofe or ororsreous 

 colors, is indeed a contemptible employment; but to inquire into the purposes of their 

 being and the part they are destined to perform in the economy of Nature, is to study 

 the wisdom of that Omniscient Being whose mandates they execute with the greatest 

 exactness. '••" * * * 



These insects (the Canker-worm) appear in the Spring earlier than any other of 

 the moth tribe— about the middle of March. Their rise, however, from the earth will 

 be delayed or hastened according to the temperature of the atmosphere and state of 

 the soil. They are found under a double form, the males being furnished with, and' 

 the females being destitute of, wings. This circumstance necessitates the females tO' 

 ascend the tree bj'^ its trunk in order to deposit their eggs upon the branches. The 

 males by their wings resort to them, and are found in the evenings hovering round 

 the trees. In three or four days after they begin to rise, they are found sub-copula. 

 This oiiice is performed in eleven or twelve days after their first appearance. The 

 males die and disappear. In thirteen days the females deposit their eggs. These they 

 place in the crannies of the bark in the forks of small branches; and where there are 

 spots of moss upon the smaller limbs they seem most fond of insinuating themselves 

 into the cavities between its leaves. For this purpose the females are lurnished with a 

 tube through which the egg is passed, with which she investigates the appertures in 

 the bark or moss, and ascertains their depth. * '^ * Each female lays at 

 a medium an hundred eggs. The ultimate purpose of their being thus performed^ 

 they die. 



The egg is elliptic, 1-30 of an inch in length, of a pearl color, with a yellowish cast. 

 As the included animal advances in ripeness the egg assumes a brownish hue ; in 

 twenty days is of a lead color, and with a moderate magnifier the larva may be seen to 

 move in the shell. On the twenty-first day the larva breaks from its prison, is one line 

 in length, and furnished with ten feet — six anterior and four posterior. * * "'•" 

 They are commonly hatched about the time that the red currant is in blossom, and the 

 apple-tree puts forth its tender leaves. * * * 



On the twenty-sixth day from their quitting the egg they begin to cease from feed- 

 ing and descend by the trunk of the tree ; when arrived at its foot they with great la- 

 bor penetrate the earth near it to different depths ; and this appears to depend in part 

 on the quality ot the soil and in part on the vigor of the animal. In grass land they 

 are found from one to four inches beneath the surface, and when the trees stand in 

 plowed land, if the soil be loose, they penetrate to the depth of seven or eight. * * * 



It has been observed above that they descend by the trunk of the tree ; all which 

 descend in this manner enter the earth near it. This is their natural and regular course, 

 and hence the greatest number of them is found within a circle, whose radius extends 

 four feet from the trunk. But some will always be found at a greater distance, accord- 

 ing to the area which the tree covers ; for if dislodged by wind or accident at the time 

 when they are about to seek the earth, they cover themselves near the spot they fall- 

 on. In recurring to the structure of the female insect we see at once the reason why 

 they are naturally confined to a small circle. 



The larva or catterpillar is, when full grown, about nine lines long; the head pale,. 



