6 BULLETIN 111*7, U. S. DEPARTMENT OF AGRICULTUEE. 



likewise quite distinct. In many respects the ubiquitous E. fresenii 

 as well as E. lageniformis^ both aphid parasites, are more nearly 

 allied to it than other known species. The similarity is due to the 

 smoke-colored hyphse and conidia, the peculiar secondary conidia, 

 and the dark resting spores, characters present in all of the forms 

 which were regarded by Thaxter as sufficiently distinct from the typi- 

 cal Entomophthora, such as E. aiiUcae^ to justify a group of sub- 

 generic {Triplosporium) value. 



DESCRIPTION. 



Entomophthora fumosa, n. sp. 



Conidia typically more or less fusiform, 16 to 20 microns by 8 to 

 10 microns, distinctly smoke- colored, tapering rather abruptly 

 toward both the base and apex, occasionally elliptical. Apex sharply 

 rounded, base or papilla weak but clearly visible; conidiophores 

 simple, smoke-colored, slender, arising directly from spherical yel- 

 lowish hyphal bodies. Secondary conidia elliptical, small, 4 by 8 

 microns, rather thick-walled, without papillae, arising on 1 to 5 

 slender, capillarylike conidiophores from each primary coniclium; 

 Resting spores (zygospores?) apparently arising from conjugation 

 of hyphal bodies, spherical, opaquely black, 15 microns in diameter, 

 invariably provided with a hyaline protuberance or appendage. 

 When crushed, black exospore cracks, revealing internal, hyaline, 

 spherical, thick-walled spore. Host attached to substratum by in- 

 sertion of proboscis. 



On Pseudococcus citH Eisso on Citrus spp., Florida; on Pseudo- 

 coccus citri on Ficus sp., Louisiana; on Phenacocciis sp. on Hibiscus 

 sp., Louisiana. 



MICROSCOPIC CHARACTERS. 



It is a relatively simple matter with a microscope to recognize this 

 disease very early in its development, because the organism which 

 causes it is large and possesses unique characters. Insects which are 

 suspected of having the disease are crushed in water and mounted on 

 a slide. If the organism is present, bodies such as those represented 

 in Plate I, 16, will be observed. Such bodies are always evident if a 

 milky white liquid emerges when the body is crushed, and often they 

 can be detected, though in lesser numbers, before the blood appears 

 white. They have been termed "hyphal bodies" and, while some- 

 what variable, in so far as shape and appearance are concerned, in 

 the different species of the genus, in the species under consideration 

 they are perfectly spherical, very thin walled, and are filled with a 

 very finely granular protoplasmic content. The wall which sur- 

 rounds these bodies is exceedingly thin and plastic, as shown by the 

 fact that when pressure is applied unequally upon their surfaces the 



