24 



CALIFORNIA STATE HORTICULTURAL COMMISSION. 



DIPTEROUS INSECTS. 



In the great family of dipterous or two-winged flies, we find very 

 many of our worst pests ; among them the many fruit flies, which do so 

 much damage by laying their eggs in the ripening fruit, and which 

 hatching out into a mass of crawling maggots render it wholly unfit for 

 use; but at the same time this order gives us very many of our best 

 friends, and prominent among them are the following : 



Lestopihqnus ieerya. (Plate 

 I, Figs. 5, 5<z; also Fig. 13.) 

 This is an exceedingly small, 

 two-winged fly, which was 

 found at work on the cottony 

 cushion scale at Sidney, N. 

 S. W., by Albert Koebele. 

 It is now thoroughly estab- 

 lished all over California 

 wherever the cottony cushion 

 scale is found, and has proved 

 itself a valuable auxiliary to 

 th" 1 Vcclalia cardinalis in keep- 

 ing that pest in check. 



FIG. 13. Lestophonus ieerya, enlarged. 



Celatoria erawii, Coquillett. (Fig. 14.) This is another of our 

 beneficial flies, being an internal parasite of the well-known twelve- 

 spotted squash beetle, so common in fruit-growing districts, and is one 



Larva. 



*&'< it *&&'*' 

 ^^Bl^^ 



Female, enlarged. 



FIG. 14. Celatoria orauii, Coq.uillett. 



Pupa. 



of the rare instances that have been recorded of a beetle being destroyed 

 by the larvae of a fly. It is not only interesting to an entomologist, but is 

 of great assistance to the horticulturist in reducing the numbers of such 

 a serious pest. Mr. Craw discovered this parasite in the neighborhood 



