40 SECOND REPORT OF THE STATE ENTOMOLOGIST. 



their body semi-fluid, so that it was difficult to remove some of the ex- 

 amples without breaking them and discharging the black fluid. 



The disease was probably identical with that which had frequently 

 been observed by me in attempting to rear larvae of other species of 

 Lepidoptera in confinement, and by other entomologists, and with that 

 which was studied by Professor Forbes, in 1883, when a very large per- 

 centage of the caterpillars throughout the northern and eastern portions 

 of Illinois were killed. It was found by him to be a contagious disease, 

 resulting from the presence within the larvce of innumerable bacteria, 

 probably Micrococcus bo?nbycis, and in no ways distinguishable from the 

 flache'ri, which was investigated by Pasteur with such brilliant results at 

 the time when, as a silk-worm disease, it was inflicting an annual loss of 

 hundreds of millions of dollars annually upon the silk industry of Eu- 

 rope. See Prof. Forbes' address " On a Contagious Disease of Cater- 

 pillars," delivered before the State Horticultural Society of Illinois, in 

 December of 1883. 



The same disease has also been noticed by me, as destroying Pieris 

 rapce larvae in cabbage fields in the vicinity of Albany. 



Heteropacha Rileyana Harvey. 



Mr. G. R. Pilate, of Dayton, Ohio, sent under date of July 2 2d, some 

 small larvae of this species and also some eggs, found by him a few days 

 previous. Not being able to rear them, in subsequently communicating 

 with him, I learned that he had found no difficulty in breeding the spe- 

 cies by the following method: " I use large glass candy-jars, eighteen in- 

 ches high by eight wide, for my larvae, putting in them about an inch 

 and a half of white sand, slightly moistened, for if too wet it will kill 

 the larvae. For those that bury, I use three inches of sand. Upon the 

 sand a piece of paper is placed to hold the excrement and permit of its 

 easy removal when fresh food is supplied. Always give them Honey- 

 locust to eat {Gieditschia triaccmthos) and not the black locust." 



Later, additional eggs were sent which had been laid the 8th of Au- 

 gust, with the statement that " when first laid they are pure white, with 

 the exception of the three spots on the top and sides." 



Hemileuca Maia {Dniry). 

 Mr. Pilate informs me that from about three hundred (eggs }) of this 

 species, found on basket-willow {Sa/ix viminalis), he had obtained about 

 one hundred pupae. The species appears to be an easy one to rear in 

 confinement, for in colonies reared by me from the egg-belts, nearly all 

 attained their perfect stage. Larva collected at somewhat an advanced 

 age upon their food-plants are quite liable to have been parasitized, for 



