250 



THE MONTHLY BULLETIN. 



THE DIPTEROUS PARASITE OF THE COTTONY CUSHION SCALE. 



Cryptochwtum iccrinv Will. (Family AgromyzidiE). 

 {Lestophontis iceryce Will.) 

 (Fig. 246.) 



General Appearance. — The adults of this very beneficial insect are 

 exceedingly small two-winged flies about one sixteenth of an inch long. 

 The head and thorax are metallic blue and the abdomen bright irides- 

 cent green. The antenna are black; legs black or dark brown with 

 feet light ; wings grayish hyaline with dark brown veins. 



Life History. — The eggs are deposited by the females in the egg-sacs 

 of the cottony cushion scale and the young maggots feed upon the 



Fig. 246. — The dipterous parasite (Cryptoclur- 

 ium iceryce Will.) of tlie cottony cushion scale. 

 Adult and egg. Very greatly enlarged. (After 

 Williston. ) 



eggs of this pest. The entire life history is passed within the protect- 

 ing sac of the host, the adults emerging as by magic from the masses 

 of the scale. 



Distribution. — This fly is practically confined to the citrus-growing 

 sections of Southern California and is more often found in Los 

 Angeles, Orange and San Diego counties. 



While it is not as consistent and reliable in its work upon the cottony 

 cushion scale as are the ladybird beetles {Novius cardinalis and N. 

 koehelci) yet its work is often phenomenal. During the summer of 

 1912 Mr. A. S. Hoyt, Deputy State Quarantine Officer, bred quantities 

 of this species in Los Angeles County. He believes that the fly is often 

 responsible for the good name of the Vedalia. Certainly its rearing 

 and distribution is well worth while. 



