Insecutor Inscitiae Menstruus 



Vol. II MARCH. 1914 No. 3 



ON THE GENUS CRYPTOCH>ETUM 



{Diptera, Muscida acalyptrata) 

 By FREDERICK KNAB 



The anomalous genus Cryptochatum was first brought to the attention 

 of American entomologists through the discovery that in Australia certain 

 species were parasitic on scale insects and through their introduction into 

 California to control the injurious scale insect Icerya purchasi. One of 

 these forms was described by Williston under the name Lestophonus 

 icerya, from material sent to the United States Department of Agricul- 

 ture from AustreJia by Mr. Frazer S. Crawford (Insect Life, vol. 1 , p. 2 1 , 

 1 888). Shortly afterwards a second species was described in AustrzJia 

 by Skuse under the name L. monophlehi (Proc. Linn. Soc. N. S. Wales, 

 2 ser., vol. 4, p. 125, 1889). The vjJidity of this last species has been 

 denied by Williston (Insect Life, vol. 1, p. 330), but reaffirmed by Riley 

 (Proc. Ent. Soc. Wash., vol. 1 , p. 263, 1 890) and recently by Melan- 

 der (Journ. N. Y. Ent. Soc, vol. 21, p. 248, 1913). 



Recently specimens of Ciyptochistum bred in Ceylon from scale insects 

 of the genus Walk.eriana were submitted to the writer for determination and 

 this has caused him to go over the literature and the material in the national 

 collection. As it appears that there is still doubt in some minds that the 

 two forms described from Australia are distinct, it seems worth while to re- 

 cord the result. I can point out additional characters for the two Australian 

 species, and the Cingalese form proves to be distinct and is described 

 herewith. Professor Melander, in his diagnosis of the genus (1. c, p. 246), 

 states that a single pair of scutellar bristles is present, but careful exauni- 

 nation of all three species shows that there is a series of short bristles 

 medianly on the apical margin which are but weakly ditferentiated from 



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