22 
were then enclosed. The contents were now dusted with spores 
of lsaria vexans, sprinkled with water and closed. The box 
was subsequently sprinkled with water on alternate days. On 
Aug. 7 some of the bugs were dead and covered with the fun- 
gus. About a teacupful of bugs were added at this time. 
On Aug. 9 very many were dead and covered with the fungus, 
and by Aug. 13 nearly all had been killed. 
The presence of the disease-producing fungus in the labora- 
tory was a source of great annoyance, interfering very serious- 
ly with the breeding of insects of various sorts. It was almost 
impossible to get any insects to mature. as the disease attacked 
them almost indiscriminately. A dead grasshopper, while dry- 
ing upon a spreading-board, was invaded with the resultshown 
in Fig. 12, Plate 2. Out of several hundred bag-worms ( Thy- 
ridopteryx ephemerceformis Steph.) less than a dozen matured. 
The disease produced in the laboratory rooms an epidemic 
among insects from which there was no escape. Fig. 138, Plate 
2, Shows one of these bag-worms, killed by the fungus. 
Generally speaking these and other experiments showed 
that the Jsaria vexans will grow profusely upon all dead insects, 
and that it will kill also very many others that may be some- 
what weakened by confinement. In case of the bag-worms 
a large number were crowded together in arather small breed- 
ing-cage, which may account for their weakened condition. 
But many healthy insects, when introduced into the room, soon 
caught the disease and died. In this manner even mosquitoes 
and the common house-flies were killed in large numbers. 
Another fact became also very plain, i. e., that the fungus grew 
very rapidly upon dead chinch-bugs, which were covered with 
a dense growth in three or four days. The spores are not 
easily killed by a high temperature. and some that were ex- 
posed to almost 140 degrees F. showed their vitality when 
brought in contact with feeble chinch-bugs, soon killing them 
and covering their dead bodies with the characteristic white 
shroud. <A large number of spores are at the present time ex- 
posed to our ‘‘gentle zephyrs” to see if they can stand this 
treatment as well. 
None of the diseases that kill chinch-bugs can be called a 
true remedy, as we can do but one part of the work, while cli- 
matic conditions must do the other. It is easy to produce any 
