178 The Ohio Journal of Science [Vol. XVIII, No. 6, 



tinctly beneficial. This fact has been utilized in actual practice 

 in control measures against the sugar-cane leaf-hoppers in 

 Hawaii with marked success. 



From the biological viewpoint, the study of the interrelations 

 of these parasites with their host has a direct bearing upon the 

 interesting problem of insect parasitism in general. Thus the 

 specialization of the dryinid, and the morphological changes it 

 brings about in its host, the hopper, may and probably does have 

 parallels in the relations between other groups of parasitic 

 insects. with their hosts. 



These Homoptera are subject to parasitism in all their 

 stages; namely, egg, nymphal, and adult. In North America 

 three orders of insects are known to contribute their quota of 

 the parasites of this group — the Hymenoptera, Diptera, and 

 Strepsiptera; and in Australia and Hawaii, certain of the 

 Lepidoptera are considered to be parasitic, though this relation 

 is not definitely established. 



The eggs are known to be parasitized by species of the 

 PlatygastridcB, MymaridcB, Encyrtidce, Eiilophidce, and Tricho- 

 grammidcB (Perkins, 1905-1906). The nymphs and adults are 

 parasitized by the Anteonince, Pipunculidce, Strepsiptera, Epipy- 

 ropidcE and Encyrtidce (Perkins, 1905) and Chalcididce (Misra, 

 1917). 



The relative importance of these parasites as natural checks 

 varies probably in different localities. However, in Ohio, at 

 least in the northern half, the Anteonince are the most important. 

 Strepsiptera have been recorded as being relatively numerous 

 in regions further south, and their rather obscure habits and 

 small size possibly may account for an underestimation of 

 their importance in this locality. Frequently their host survives 

 and thus it seems that their attack is not always fatal. Certainly, 

 however, they form an important link in the chain of natural 

 enemies. 



The following paper is confined to an account of the Anteo- 

 nince. Material was more plentifully obtained for their study, 

 and their greater importance warranted a more extended 

 investigation. Most of the parasites used in the life history 

 studies were bred from hoppers taken near Sandusky and 

 Columbus, Ohio. 



