THE CANADIAN ENTOMOLOGIST. 83 



though this suggestion is the evident consequence of his discovery — and 

 as I found it not done by anybody else, I recommended experiments to 

 be made with the yeast fungus. The experiment with the Potato Bug has 

 proved that yeast fungus externally brought in contact with insects, kills 

 them. Therefore objections based on botanical grounds can not more 

 be admitted, and the Botanists will sooner or later find the true 

 explanation of the facts. 



It has been contended that "as long as a scientific basis for the use 

 of the yeast is not more established, a practical application of the same 

 is simply out of question." This assertion, is a rather strange one, the 

 more so as nothing is known about the scientific basis of Pyrethrum, of 

 Paris green and other remedies. It has apparently been overlooked that 

 I found in the dead beetles which had been sprinkled, in the large sinus 

 of the wings, spores in quantity. Those spores resembled the figures 

 given by Dr. Rees (Unters. ueber die Alcoholgaehrungspilze Leipzig, 1870, 

 pi. 1, f. 15, e. d.) and were so numerous and so distinct that I could not 

 have been deceived, the more as I am familiar with the blood fluid of 

 insects and its corpuscles. I did not find such spores in the sinus of the 

 wings of beetles which had not been sprinkled. There is nothing in the 

 size and the shape of the yeast spores which could prevent them from 

 entering an insect's body and producing disease. 



Since the above was in type I have received a letter from Germany 

 stating that sprinkling with the atomizer of diluted (compressed) yeast, a 

 half an ounce package in three liter of water, on Aphides in greenhouses, 

 was successful to an exceeding degree. 



NOTES ON THE LARVA OF HETEROCAMPA 

 PULVEREA, G. & R. 



BY G. H. FRENCH, CARBONDALE, ILL. 



Length when at rest, 1.25 inches; in shape tapering slightly from the 

 middle forward, but more rapidly from that point backward ; the body 

 deeper than broad. General color bright clear green, a little spotted with 

 white, marked as follows : head gray, a little lighter through the centre ; 

 joint 1 contains two dark purplish black warts on the dorsum, reddish 



