XV 
The agricultural insects which have chiefly engaged our atten- 
ion during the two years past are the chinch bug, the Hessian 
LY, the CORN PLANT LOUSE, the WHITE GRUBS, the CUTWORMS, 
nd the wire worms. To the Hessian fly, the corn root louse, 
nd the white grubs, especially, we have given much time and 
ibor, carrying the first through the season, following its de- 
elopment from generation to generation, on wheat sown at in- 
3 rvals on small plots enclosed by gauze, carrying the corn louse 
imilarly through the year, on hills of corn tightly enclosed by 
irge gauze frames and stocked from time to time with plant 
ce from the fields, and following the white grubs throughout 
he season with similar experiments. The most interesting re- 
ults, so far as the Hessian fly is concerned, are the demon- 
tration of the occurrence, under some circumstances, of a par- 
ial second spring brood in Illinois and a confirmation of our 
uevious work with regard to the great importance of watching 
he volunteer wheat in regions infested by the fly. The corn 
>lant louse work has given us additional details with regard 
o the life history of this most important species and a firmer 
•asis for field economic experiments now in progress; and our 
•reeding experiments with the white grubs have shown that the 
urrent account of the life history of these insects is seriously 
it fault, and that mistaken practical conclusions have been a 
requent consequence. 
These experiments have likewise enabled us to distinguish the 
rubs corresponding to different species and groups of species of 
he beetles, and so to prepare the first technical descriptions of 
hese larvae which have ever been published in America. 
Experiments with horticultural insects have been limited 
hiefly to those with the plum curculto, —intended to determine 
he precise character of its food and feeding habits and the sus- 
eptibility of the adult to destruction by arsenical poisons,—and 
o those with the strawberry thrips, elsewhere referred to. 
"he plum curculio experiments were entirely successful, and 
he details will be given in an article of this report. Those for 
he Thrips, however, were less satisfactory. Trials were made 
dth various adhesive substances, to be sprinkled on the plants 
iable to injury with a view to entangling or liming the deb¬ 
ate insects upon the surface of the leaf or blossom, but noth- 
ag was found effective for this purpose which was not also in- 
urious to the plant. As further experiments will be made in 
his direction, no report of these trials is considered necessary. 
