68 INSECTS INJURIOUS TO VEGETATION. 



vicinity. They are not to be mistaken for the more common 

 apple-worms, from which they are easily distinguished by their 

 inferior size, and by their want of feet. In 1831, Mr. Thomas 

 Say, in a note on the plum-weevil, stated that it " depredates 

 on the plmn and peach and other stone-fruits ;" and, that his 

 " kinsman, the late excellent Wm. Bartram, informed him it 

 also destroys the English walnut in this country."* 



Observers do not agree concerning some points in the econo- 

 my of this insect, such as the time required for it to complete 

 its transformations, the condition and place wherein it passes 

 the winter, and the agency of the curculio in producing the 

 warts or excrescences on plum and cherry trees. The average 

 time passed by the insect in the ground, during the summer, 

 has appeared to me to be about three weeks ; but the transfor- 

 mation may be accelerated or retarded by temperature and 

 situation. It has also been my impression that the late broods 

 remained in the ground all winter, and that from them are 

 produced the beetles which sting the fruit in the following 

 spring. Dr. Burnet's observations coincide with this opinion. 

 According to him, the insect "undergoes transformation in 

 about fifteen or twenty days, in the month of June or fore part 

 of July; but all the larvse (as far as he had observed), that go 

 into the earth as late as the 20th of July, do not ascend that 

 season, but remain there in the pupa stage until next spring." 

 Dr. Tilton, in his account of the curculio, stated that "it re- 

 mains in the earth, in the form of a grub, during the winter, 

 ready to be metamorphosed into a beetle as the spring ad- 

 vances." According to M. H. Simpson, Esq., of Saxonville, 

 the larva?, or grubs, " go through their chrysalis state in three 

 weeks after going into the ground, and remain in a torpid state 

 through the season, unless the earth is disturbed."! Dr. E. 

 Sanborn, of Andover, has come to entirely different conclu- 

 sions, from a series of experiments made upon these insects. It 

 is his opinion that they do not remain in the ground, during 

 the winter, either in the grub or in the beetle state ; but that, 



* Descriptions of Curculionites, p. 19. 8vo. New Harmony, 1831. 

 t Hovcy's Magazine, Vol. XVI, p. 257, June, 1850. 



