THE RED FUNGUS. 21 



valiia])lo data on cultural methods and on the introduction of arti- 

 ficially grown spores. Dr. George F. Atkinson, of Cornell Univer- 

 sity, was successful in growing cultures of this fungus during the 

 summer and fall of 1907 from material sent him by Mr. Worsham, at 

 that time an agent of this bureau, and imder date of September 30, 

 1907, sent tlie authors at the Orlando Laboratory cultures from 

 which infections were secured in the grove. 



DESCRIPTION. 



A glance at Plate I, middle figure, would give one unfamiliar with 

 this fungus a sufficiently correct idea of its appearance and make 

 possible its identification in the grove. (See also Plates III and IV.) 



Dr. Webber's original technical description is as follows:^ 



Stroma hj^^ophyllous, depressed hemispherical, pinkish buff or cream colored, 

 coriaceous, l-2imm. in diameter; mycelial hypothallus grayish white, forming a thin 

 meml)rane closely adhering to the leaf and extending about 1 mm. beyond the stroma; 

 perithecia membranaceous, at first superficial, later becoming irregular, reniform or 

 orl)icular in mature specimens, and opening by small, round, or elliptical pores or 

 slits; basidia crowded, filiform, slender, continuous, 28-40/i long, 0.94-1.5u in diam- 

 eter; paraphyses al)undant, slender, projecting beyond the basidia, G5-100/t long, 

 f-]/( in diameter; sporules fusiform, continuous, mucilaginous, hyaline, sometimes 

 obscurely 3—1 guttulate, 9.4-14. Iw long by 0.94-1.88// -wide, very abundant and erum- 

 pent, forming conspicuous coral-red or rufous masses. (Parasitic on Aleyrodes citri 

 R. Sc H., infesting citrus leaves in Florida.) 



Dr. Webber further states that peculiar darkened cells occur at 

 irregular intervals in the paraphrases w'hich are quite characteristic of 

 this sj)ecies of fungus. 



DEVELOPMENT. 



If in the process of dissemination the spores find a favorable resting 

 place and the weather conditions permit, they soon germinate or 

 grow by sending out rootlike processes known technically as hyphaB 

 or mycelial threads. Should one of these succeed in finding a vul- 

 nerable spot in a wliite-fly larva or pupa, the growth of the fungus 

 becomes very rapid and the insect is soon killed. The following 

 description of the development of the fungus within the insect has 

 been taken, with slight changes, from that of Dr. H. J. Webber,^ 

 which in the main has been verified by the authors. 



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

 white fly is the appearance of sligiitly opaque, yellowish spots, usu- 

 ally 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 honeydew than normally. As the fungus develops, 

 the internal organs of the larva appear to contract away from the 

 margin, leaving a narrow circle, which then becomes filled with the 



» Bui. 13, Div. Veg. I'hys. and Path., U. S. Dept. Agr., p. 21, 1897. sidem, pp. 23-24, 1897. 



