X 
the other hand, was rare. From a correspondent in Carroll county, 
in the northern part of the State, I learned that these insects 
have been so numerous there for several years as to compel the 
replanting of most of the corn on sod. 
The practice of spraying apple-trees in spring to protect the 
fruit from the codling moth, or apple worm, is now rapidly 
becoming* general, based largely in this State on the experiments 
and recommendations of this office as published in our Bulletin 
No. 1.* The results for 1887 were generally very encouraging, 
but those for 1888 were less decisive, owing to an extraordinary 
scarcity of the insects themselves, especially in Central Illinois. 
This was evidently due to the occurrence in 1888 of an unusual 
apple crop following a season of unusual scarcity of this fruit. 
‘ A new and peculiar insect observed by us for several years, and 
known in the office as the burrowing web worm, occurs abundantly in 
grass, and in corn after sod, not in numbers, however, so far as now 
known, to be a serious enemy to the latter crop. This species was 
bred in 1888 to a moth, Pseudanaphora arcanellci , described else¬ 
where in this report. A less common species of similar habit was 
also bred in 1888, and proved to be a Csenogenes, described on 
another page as C. mortipennella , Grote. 
The history of the Hessian fly during the past two years ex¬ 
hibits anew the effect of drouth upon the multiplication of that 
species. Many of the wheat fields of Southern Illinois in regions 
which had been free from the fly the preceding year, showed it in 
such numbers at harvest time in 1887 as to make it seem probable 
that the following crop would suffer heavily; but a sefere mid¬ 
summer drouth following, prevented almost entirely the growth of 
volunteer grain, and very probably also dried up the larvae and 
pupae of the fly in the field. As a consequence, these neighbor¬ 
hoods in 1888 were almost absolutely free from evidence of at¬ 
tack, although in adjacent counties, wjiere the drouth was less 
severe, the fly was noticeably abundant in the fall of 1887 and in 
the following spring. 
Experimental sowings in 1887 and 1888, made to trace the sum¬ 
mer history of this insect, failed because of the drouth, in the 
former year completely, in the latter partially,—only the latest 
planting growing. One plot, sown at Albion, Edwards county, 
July 28, started slowly, and was heavily attacked by chinch bugs 
and grasshoppers. There no Hessian flies were detected August 
24, but by September 13, larvae of almost all ages occurred in 
great abundance, and by the I8tli a few had formed fresh puparia. 
Transferred to the office at Champaign and kept in the open air, j 
♦The method of field application now most commonly used differs widely from that of my pub¬ 
lished experiments. In the latter, the finest possible spray was applied by passing the nozzle about 
through the foliage of the tree. In the common orchard practice a much coarser spray is thrown 
from beneath, through a short tube, with sufficient force to reach the top of the tree after leaving 
the nozzle A greater amount of water being thus applied, a smaller proportion of the poison is 
necessary. More than one pound to two hundred gallons is superfluous, and may be injurious, 
whereas in my own experiments we found a pound to fifty gallons harmless. 
