ENTOMOGENOUS FUNGI 261 



the entomogenous fungi in combating insect pests, the 

 most satisfactory results have been obtained by P. H. 

 Eolfs and H. S. Fawcett of the Florida Agricultural 

 Experiment Station in the control of certain Coccidae 

 and Aleyrodidae. Some of the most important of these 

 fungi and the insects on which they prey are as follows : 



The genus Aschersonia, 1 belonging to the Sphaero- 

 psidales (page 61) contains several species which attack 

 insects, among the most important of which are A. 

 aleyrodis, Webber, which is well known in Florida 

 and Jamaica, where it destroys Aleyrodis citri, and in 

 Cuba, where it attacks A. citri and A. Howardii. It 

 has been reported on several undetermined species in 

 Ceylon, while uncertain reports have indicated that in 

 Java it occurs on A. longicornus and in Brazil on A. 

 horridus. 



Fawcett says 



The first indication of the effect of the fungus on the larva 

 of the white fly is the appearance of slightly opaque, yellowish 

 spots unusually near the edge of the larva. In the early stages 

 of infection the larva becomes noticeably swollen, and appears 

 to secrete a greater abundance of honey-dew than normally. As 

 the fungus develops, the interior organs of the larva appear to 

 contract away from the margin, leaving a narrow circle, which 

 becomes filled with hyphae. Shortly after this the hyphae 

 burst out around the edge, forming a dense marginal fringe. 

 This may form all around the larva at about the same time, or 

 develop at one portion of the margin sooner than the others. 

 Death usually ensues, it is believed, before the hyphae burst 

 out. The fungus does not spread over the leaf to any extent, 

 but grows upward in a mass, gradually spreading over the 

 larval scale. It is not uncommon to find the pycnidia, with 

 their bright, coral-red masses of sporules, formed in a circle 

 around the edge of the larva while it is yet visible. As the 

 Aschersonia develops, the hyphae spread over the larva, forming 

 a dense compact stroma, which ultimately entirely envelops the 

 larva. The stroma in this stage is thin and disc-like, the 

 fructification being usually borne in a circle near the edge. The 

 hyphae, which make up the main mass of the stroma, are from 



1 Some species of Aschersonia are supposed to be the imperfect stage of 

 ffypocrella, an Ascomycete. 



