166 



Descriptions of New Species of Hymenopterous Parasites of 

 Muscoid Diptera with Notes on their Habits. 



BY JOHX COLBUEN BRIDWELL. 



The Muscoid Diptera play so large a part in the economic 

 entomology of the Hawaiian Islands that any contribution to 

 our knowledge of their enemies has its value. The injuries to 

 fruits by Ceratitis capitata, to vegetables by Badrocera cucur- 

 hitae, to meats by certain of the Sarcophaga species and the 

 annoyance and disease transmission by the house fly ; the injury 

 to cattle by Stomoxys calci trans and by Haematobia serrata; 

 the benefits in checking the seeding of the lantana by the Agro- 

 myzid seed fly ; the reduction to harmlessness of th'.' cane borer 

 {Ehabdocnemis ohscura) by Ceromasia sphenophori and the 

 beneficial effects of the attacks of other Tachinidae upon Le- 

 pidoptera make it desirable to extend our knowledge of their 

 enemies, particularly since efforts have been made in the past 

 and will doubtless be made in the future to control the worst 

 of the pests through the importation of their enemies. 

 Farther afield are the problems of the cherry, apple and 

 currant fruit flies, the root maggots, the sheep maggots and 

 the screw worms all of which at least suggest the consider- 

 ation of methods of natural control. 



So far as I can learn there are no known hymenopterous 

 parasites of the eggs of Muscoid Diptera. Their enemies 

 aside from predators appear to attack them in either the 

 pupal or larval stages. Several Pteromalids, Chalcidid? and 

 Ichneumonoids are knoAv to attack them only in the pupfirium. 

 For the practical purpose of parasitic introduction, this group 

 of their enemies have seemed of little importance for two 

 reasons: 1st, because they exercise little or no discrimination 

 in their choice of host and, 2d, because the puparia which 

 they attack are hidden away from them and require to be 

 searched for and found, a time consuming operation which 



Proc. Haw. Ent. Soc, TV, No. i, June, 1919. 



