THE PARASITIC FUNGI OF INSECTS. 77 



The Entomophthorese do not live exclusively on insects, for 

 one species has been found parasitic on the cells of the prothallus 

 of ferns, and another is parasitic on various species of the fungus 

 Tremelliacege. There is, however, a great deal of work to be done 

 before the limits of this group are defined. For instance, amongst 

 the latest investigations, it has been found that a parasite on Aphis 

 Mali, hitherto placed among the Gregarinidce, really belongs to 

 this group. Also, many different caterpillars seem to be infested 

 by separate species of Entomophthora, each of them peculiar to 

 one special genus or species of caterpillar. Thus, one species has 

 been found on the caterpillar of Euchelia /acobecB, the conidial 

 spores of which form small masses of saccharine aspect upon the 

 hairs of the infected caterpillars — hence the name, E7itomphth. 

 saccharijia. These caterpillars feed on a species of Senecio, and 

 were found dead, attached to the branches of the groundsel, head 

 downwards, but sometimes also in a normal position. 



Another species — E. PhisicB — destroyed a great many cater- 

 pillars of Pliisia gamma in France last year. The infected cater- 

 pillars presented a velvety aspect, like that of certain plants with 

 succulent hairs ; but the integuments presented a very wrinkled 

 appearance from the growth of the tufts of hyphae. 



An acarus was also very abundant on these infected caterpillars, 

 which probably assisted in the propagation of the fungus by trans- 

 porting its conidia. 



The oaks in the Garden of Acchmatisation in the Bois de 

 Boulogne were largely infested during the summer by the cater- 

 pillars of Liparis chrysorrhea ; but these in their turn were to a 

 great extent destroyed by an Entomophthora, called Metarhiziiim 

 chrysorrhecB. In this case the external aspect of the caterpillars 

 was but little altered. They only appeared a little indurated and 

 shrivelled, and the hairs had a slightly powdery aspect. They 

 were, however, full of hyphse of a brownish colour, terminated by 

 small irregular conidia, which often contained some small oily 

 globules. 



Still another species from France, which was found in the 

 woods of Meudon during the month of October. It was found 

 on a rare Orthopteroji Leptophyes p2c?ictatissima, which lives upon 

 elms, and arrives at the adult state quite late in the season — 



