7 
m to my report for last year. In several cabbage fields in 
al Illinois, I saw, in August and September, the work of this 
arrested and the insect itself almost exterminated by an out- 
of this disease. 
epidemic extremely similar to the above, possibly identical with 
|d not impossibly derived directly from it, has prevailed exten- 
during the season among the silk worms of Illinois, having, 
stance, almost completely destroyed a lot of these worms at the 
trial University which were being reared for experimental pur- 
I have this season successfully cultivated the virus of this 
ie and applied it to the destruction of other insects. 
p forest tent caterpillar, an outbreak of which species oc- 
d last year in Southern Illinois, was again seen in the same re- 
his season, but in number so greatly reduced as to inflict little if 
lefinite injury. The condition and fate of examples collected 
in Southern Illinois this year and kept in breeding cages 
they perished, confirmed my supposition of a destructive con- 
is disease among them, apparently the principal cause of their 
pearance last year. This was one of the diseases known as 
rdine, similar to that of the silk worm occasioned by the well- 
j 1 fungus Botrytis has si ana. 
bably the most notable entomological event of the year was 
xtraordinary abundance of the maple bark louse ( Pulvinaria 
>erabilis), which species occurred in destructive numbers through- 
le State, at least from Chicago to Shelbyville, and probably 
arther south. . Notes upon the life history, and details of ex- 
ij ents upon this species with insecticides, will be found upon 
er page. 
i cherry slug ( Selandria cerasi) continued abundant this year, 
ling its ravages farther to the south than the year before. It 
xtremely abundant in Central Illinois, at least as far south as 
lington, many trees being nearly defoliated by it. 
apple leaf skeletonizer ( Pempelia hammondi) and the lesser 
leaf roller ( Teras malivorana) were each more abundant, 
7, in Central Illinois, than the year before, and continued their 
es in nurseries until a later date, in some cases almost wholly 
iting advance in growth of young nursery stock. 
grape pomace fly, the larvae of which abound everywhere in 
apples and in old pomace at the cider mills, was this year 
ed as extremely injurious to grapes in Western Illinois, 
er grape pest, well known in Europe, but not hitherto reported 
lerica, (the grape phytoptus), was discovered by us this season 
t .nois, infesting certain of the native varieties. The Grape 
oxera, concerning whose status in Illinois I have received this 
l several inquiries from foreign consuls, has maintained about its 
average during the present year, doing occasional damage to 
varieties especially susceptible to it, but producing little or no 
upon the total yield of the vineyards of the State. 
