230 Agrioultural Experiment Station, Ithaca, N. Y. 



the text-books mentioned. For these reasons it has seemed best to use 

 the popular name, the Four-Lined Leaf-bug, in this bulletin, 



Thk Life History of the Pest. 



Heretofore but little has been known of the life history of the Four- 

 lined Leaf -bug. The earlier observers have given us graphic and quite 

 accurate accounts of its habits and manner of workinof. And unfortu- 

 nately they tried to reason out its life history from their knowledge of 

 the life histories of allied insects. " Bad matters have been made 

 worse " by later writers who have not tried to verify from observation 

 the guesses of the early observers ; and in consequence most of the pre- 

 ventive methods at present recommended to control this pest, being 

 based upon the old theories, are found to be entirely useless when its 

 true life history is observed. 



It is curious how some of these unfortunate guesses of the earlier 

 entomologists will cling to the literature and be handed down by later 

 writers until it seems almost presumptuous to doubt them. Our obser- 

 vations upon the Four-lined Leaf -bug during the past two years have 

 shown it to be a striking example of the necessity for more observations 

 upon our common insects and less theorizing on the guesses of earlier 

 writers who, however, *' builded the best they knew " with their meagre 

 facilities and left works which are mines of entertaining and useful 

 information. 



All of our observations have been made upon the pest as it works 

 upon currant and gooseberry bushes, but the discussion will consider 

 its other food-plants as well. Our attention was first called to the insect 

 in the latter part of June, 1892, after it had reached its adult stage. 

 Many observations were made to discover the eggs of the insect, and 

 failing in this, every available hiding place was examined through the 

 fall and early spring of 1893, to find the adults which we supposed were 

 in hibernation. However, no trace of the insect could be found after 

 it left the bushes in July, 



Fio. 4.— Nymph recently hatched; firststage. Fio. 5.— Nymph after first moult; second stage . 



During the present year we have been more successful. The insect 

 has been under observation both in the field and insectary during the 

 whole season, with the result that, although the insect has been known 



