110 Wisconsin Academy of iSliejices, Arts, and Letters. 



INSECTS INJUKIOUS TO AGEICULTUEE. 



APHIDES, (plant LICE,) 



BY P. R. HOY, M. D., Racine. 



Entomology, the history of insects, tlieir metamorplioses, 

 habits, relation to plants, etc., is a branch of natural history 

 which has peculiar claims on the agriculturist. In view of the 

 millions of dollars annually lost to the state by the deprecia- 

 tions of insects, it becomes an interesting problem how to dis- 

 tinguish in all stages of growth, our insect friends from our 

 insect foes, that we may be better fitted to cherish the one and 

 destroy the other. 



When will the representatives of the people understand that 

 Wisconsin can ill afford to dispense with the invaluable ser- 

 vices of a state entomologist? We have a host of insects, 

 peculiarly destructive, waiting for careful study, the better to 

 enable us to counteract their evil work. Not the least of the 

 advantages to be derived from the labors of an active, enthusi- 

 astic state entomologist, is the education of the farmers by 

 personal contact ; thus teaching them how to distinguish the 

 various insects by which they are surrounded, in their different 

 stages, so that this practical knowledge may be of value to 

 themselves and to their neighbors. 



Plant Lice. — Small, green, brown, black or white, soft 

 bodied insects, with or without wings ; crowding together on 

 leaves, stems, bark or roots of various trees and herbs. Many 

 species are covered with a white cottony substance, hence called 

 Woolly Aphides. The number of species is very large, not a 

 genus of plants that has not its peculiar species ; many, more 

 than. one. The apple alone, according to Fitch, has not less 



