438 Aguicultural. Experiment Station, Ithaca, N. Y. 



together with the swollen one mentioned, rubbed on nine healthy 

 grubs and placed with them in a new pot. 



On February 26th, however, no effect was seen and the experiment 

 was discontinued. The specnnens in the check-cages, died at about 

 the same rate, but none of them became swollen or pink in color. 

 It is possible that the two grubs were attacked and killed by Isaria 

 but it does not seem to act with the same virulence that is reported 

 from Europe, possibly because of different climatic conditions and 

 possibly also because of the difference in the host. 



Perraud records experiments with Botrytis tenella {Isaria densa) 

 in closed chambers. They were successful when small chambers 

 were used, but when larger chambers were used, the experiments 

 were less successful. He does not speak of its economic use. 



Paul Sorauer* says that the results of his experiments show that 

 the insects are rendered susceptible by being placed under unfavor- 

 able conditions, such as being provided with poor or insufficient 

 food, or placed in a soil which is too moist. The latter is also 

 favorable to the development of the fungus. 



Dr. Jean Dufour in Lusanne \ finds it very easy to produce the 

 disease in specimens infected with the conidia, but finds it very 

 difficult to spread the disease. He thinks that it is impossible for 

 the grubs to spread it themselves to any useful degree. His experi- 

 ence is corroborated by Frank;}: who says, that the question is more 

 difficult than it would appear. The difficulty does not consist in 

 finding a parasite on the grub, but in spreading it. 



M. E. Le Coeur|| infected also Anthonomus jpomoruni and Cliei- 

 vnatohia hrumata with Botrytis tenella. Most of the pupae re- 

 mained dead in the ground. 



My experiments were rendered very unsatisfactory because of 

 what was apparently a bacterial disease, which broke out in the 

 Btoj-age cages, as well as out of doors in places where grubs were 

 abundant. The grubs showed small well-defined, irregularly-shaped 

 patches of black, shiny skin, usually on the thorax at the bases of 

 the legs, and often on the legs themselves. In such cases the legs 

 dropped off as the disease advanced. Often the black patches ap- 

 peared on the dorsal-surface, just behind the head, and occasionally 



* Zeit. fill- Pflanzeukrankheiteii, Vol. lY, p. 267. 



+ Zeit. fur Pflaiizeukrankheiten, Vol. Ill, p. 143, 1893. 



X Deutsche Laudwirtscbaftliehe Presse, vom 19, Nov., 1892, p. 961. 



II Bull, de la Soc. Mycol. de la Fr., Vol. VIII, p. 20, 1892. 



