Wasps, Bees, and Ants 



479 



within the body. In the latter case the issuing winged adults have to bite 

 their way out. The host usually dies before its time for pupation has arrived, 

 but in some species it succeeds in pupating beforehand. The parasitic 

 Hymenopterous larvae, while degenerate in the same way as the footless, 



Fig. 673. • Fig. 674. 



Fig. 673. — A chalcid fly, Pleroptrix flavimedia. (After Howard; much enlarged.) 

 Fig. 674. — A chalcid parasite, Aspidiotiphagus cUrinus, of one of the scale-insects of 

 the orange. (After Howard; much enlarged.) 



eyeless, antennaless maggots of house-flies, are not more so. Their parasitic 

 habit has led to no such extraordinary structural specialization through 

 degenerative loss or reduction of parts as is the usual condition in other 

 parasites. 



While Lepidopterous larvae undoubtedly furnish the majority of hosts 

 for the parasitic Hj-menoptera, they are by no means the only ones. The 

 eggs and pupae of Lepidoptera as well as the larvEe, Diptera, Coleoptera, 

 HjTnenoptera in both egg and larval stages, some Hemiptera, especially 



Fig. 675. — iMheo longilarsis, a parasite which lives in a sac in the abdomen of a Fulgorid, 

 Liburnia lentulenta. (After Swazey; five times natural size.) 



scale-insects (Coccids) and plant-lice (Aphididas), the eggs of locusts and 

 other Orthoptera, and some Neuroptera in egg and larval stage, may be 

 infested; in fact the kinds of insects which may serve as hosts for the para- 

 sitic Hymenoptera strongly outnumber the kinds that do not. 



While as a general rule each parasite confines its attacks to a single host- 

 species, there are numerous exceptions; and on the other hand the host 

 itself may be attacked by more than one parasitic species; most of our familiar 

 Lepidoptera are parasitized by several different parasitic Hymenoptera. 



