110 Fungi on Aleurodes vaporariorum 



The mode of occurrence of the Cephalosporium on the Aleurodes 

 nymph agrees in every respect with Parkin's description and figure of 

 Cephalosporium Lecanii on Lecanium, where the mycelial threads with 

 their short capitate conidiophores are depicted radiating outwards from 

 the body of the nymph, but in this case dead imagos invested by a 

 weft of mycelium are also found. 



Since this Cephalosporium, which will be described in detail else- 

 where, proves to be quite distinct from Zimmermann's species and 

 indeed from all other Cephalosporia, it has been named Cephalosporium 

 Lefroyi (see Gaul. Chron. March 13, 1915, p. 139). 



Ever since P. H. Rolfs 1 demonstrated by orchard introductions 

 that Sphaerostilbe coccophila, discovered by the Tulasnes in 1865, could 

 be used to combat the San Jose scale, the use of entomogenous fungi 

 has been extensively adopted in Florida where the conditions of tem- 

 perature and moisture are conducive to the spread of fungi. Thus a 

 list of six fungi parasitic upon Aleurodes citri — Aschersonia aleyrodis 

 Webber, Aschersonia fiavo-citrina P. Henn., Verticillium heterocladum 

 Penz., Sphaerostilbe coccophila Tul., Microcera sp., and a sterile brown 

 fungus, afterwards styled Aegerita Webberi (see Mycologia, n. No. 4, July, 

 1910) — is given by Howard S. Fawcett 2 (1908) of which Sphaerostilbe 

 coccophila is stated to be rarely parasitic on this insect: a seventh is 

 added by E. W. Berger 3 (1909), a species of Sporotrichum, which is 

 stated to infect the adult and some larvae. 



According to the Report of the Entomologist 4 , Florida (1913), 

 natural mortality of white fly is caused mostly by Microcera. On the 

 other hand, Morrill and Back (1912) 5 report that mortality from un- 

 explained causes proves to be the most important element of natural 

 control. This mortality has never been taken into consideration in 

 previous publications, and in the past no little confusion has existed 

 owing to the failure to distinguish between the benefits derived from 

 it and those from fungus parasites. Microcera is stated to be normally 

 saprophytic. 



We are therefore led to wonder to what extent the mortality amongst 

 scale insects is really due to fungi. Both in Florida and the West 



1 P. H. Rolfs in Fid. Ayr. Exp. Sta. Bull. 41 (1897). 



2 Howard S. Fawcett. Fungi parasitic upon Aleyrodes citri. Thesis Univ. State of 

 Florida, June, 1908. 



3 E. W. Berger in Flu. Ayr. Exp. Sta. Bull. 97 (Feb. 1909). 



4 Florida Agr. Exp. Sta. Ann. Kept ( I t»l 3), liv-lviii. 



6 A. W. Morrill and E. A. Back in U.S.A. Dept. Agr. Bur. of Ent. Bull 102 (1912) 



