28 
THE CHINCH BUG. 
latter is chiefly a translation of a paper by Metschnikoff in the Zoolog- 
iselier Auzeiger for 1880, pp. 41-47 in which it is shown the Russian 
naturalist successfully induced the growth of the fungus, Isaria de- 
structor ■, which had destroyed the celebrated A nisoplia Austriaca , a grain 
pest in Russia, in beer inash. Successful attempts were made to iufest 
healthy larvae with green spores taken from diseased larvae found in 
the fields, but no mention is made of success, or even of experiment with 
the only practical substance — the beer-mash culture. 
Professor Riley has always doubted the possibility of any practical 
success in this direction, and has pointed out the difficulties in the way. 
(See American Naturalist, November, 1883, p. 1170.) 
In the introduction to the Fourth Report of the U. S. Entomological 
Commission (LXXXV) he makes use of the following language : 
In treating of the use of yeast ferment or other fungus germs we have used essen- 
tially the language of the first edition. Time has only served to confirm us in our 
opinion of their practical futility in the field. The question of the practical use of 
these micro-organisms — these disease germs — as insecticides is a very fascinating one, 
and is much written about just now ; but unfortunately it proves most alluring to 
those who have had the least practical experience in coping with injurious insects in 
the field, and is much more apt to assume importance to the closet theorists than to 
those who, from experience, are conscious of the difficulties involved in its applica- 
bility. 
It will also be apropos to quote Professor Forbes’ latest utterauce 
upon this point. He says : 
Finally, the artificial cultication of the germs of the contagious diseases of the chinch 
bug, with a view to spreading these diseases at will by means of such artificial cult- 
ure. This is a theoretical remedy only, and much additional study and experiment 
will be required to put it on a practical basis. 
WET WEATHER AND THE CHINCH BUG. 
Tlie great preponderance of evidence favors the idea, now considered 
well established, that wet weather is inimical to this insect. Dozens, 
we may almost say hundreds, of instances are on record in which the 
Chinch Bugs, after successfully hibernating in great numbers, have been 
rendered harmless by a wet spring, and in which, having laid their eggs 
and appeared again as the spring brood with greatly increased forces, 
a spell of rainy weather in early summer has caused them to vanish. 
Hence, it follows that dry seasons favor the increase of the pest ; and 
careful observation convinced Riley and others that after a season of 
moderate abundance (presumably therefore not a wet season) the occur- 
rence of the bugs in destructive numbers the next season depends al- 
most entirely upon the wetness or dryness of the ensuing spring. 
The exact method in which wet weather accomplishes the destruction 
of the insect is a somewhat disputed point. That it is not actual sub- 
mergence was pointed out by Professor Riley in his second Missouri 
report, and still further proven by an observation made by Hon. Will- 
iam McAdams and reported by Professor Forbes in his first report as 
