38 
shaken ina jar of water. This was mixed with about three 
gallons of tepid water and allowed to stand for one day. It was 
then applied by means of a knapsack sprayer to a field of cab- 
bage in which were many apparently healthy and a few diseased 
caterpillars; in three days scarcely a live caterpillar was to be 
seen. All were dead and clinging to the leaves. 
Many diseased worms were collected and dried on a bit of the 
leaf to which they were fastened. It is to be hoped that from 
these dried caterpillars, or from the pure cultures of the bac- 
teria, the disease may be started again the next season. 
DISEASE OF TENT-CATERPILLARS. 
A disease very similar to that attacking the caterpillars of 
the cabbage-butterfly was found to attack the tent-caterpillars. 
A single specimen was found at Taylor’s Falls on June 15. 
The loose flaccid skin with the body-juices fast becoming pu- 
trid hung toa plant. The color of the larva was practically 
normal, but the form was merely that of a bag. 
A dilution-culture yielded two species of bacteria in abund- 
ance. Pure cultures were made from these, from which it may 
be possible to start the disease during the coming season. Un- 
fortunately by the time that the cultures were obtained, the 
caterpillars had all disappeared, rendering any immediate 
attempt to infect them impossible. This disease occurs with 
great regularity in Minnesota, most usually becoming powerful 
enough to kill the great majority of these very destructive 
caterpillars during the third season in which they are numer- 
ous in any particular place. During the first season of the 
presence of these caterpilars but little damage is caused be- 
yond the defoliation of their most favorite food, the linden; in 
the second season they are very numerous, and sometimes 
defoliate every plant over a large area; in the third season im- 
mense numbers hatch, but before they reach their full size the 
disease attacks them, and it is sometimes difficult to find healthy 
caterpillars. HKven if some succeed in forming their beautiful 
golden-yellow, silken cocoons, it is found that they die inside 
of them and before assuming the pupal stage or soon after- 
wards. It would be very important to introduce this disease 
during the first season and thus save great losses and 
annoyances. 
