64 MISC. PUBLICATION 17 4, U.S. DEPT. OF AGRICULTURE 



hessian-fly puparia collected at Muncy, Danville, Ford City, and 

 State College, Pa., and at Hagerstown, Md. At that time it was 

 tentatively identified by the writer as a probably new species of 

 Cheilonewrus. Specimens were subsequently submitted to P. H. 

 Timberlake, an expert on this particular group of Chalcidoidea, who 

 expressed the opinion that they were G. elegans Dalman. European 

 specimens of Dalman's species identified by G. Mayr and Garcia 

 Mercet were later obtained by the writer, and Timberlake's identi- 

 fication of the American material was confirmed. 



HOSTS AND LIFE HISTORY 



If published records are correct, Cheilonewrus elegans is parasitic 

 upon* not only the hessian fly but also at least two species of scale 

 insects, viz Kermes sp. and Pulvinaria vitis Linnaeus. The species 

 of Cheilonewrus are believed to be somewhat less polyphagic than 

 many species of chalcidoids, and for that reason a question may arise 

 as to whether or not the same species is involved in all these records. 

 Unfortunately it is impossible to verify this, since no descriptions 

 are given of those species said to have been reared from coccids. In 

 North America C. elegans to date has been reared from no other 

 host than the hessian fly. 



Investigations carried on by Myers, Hill, and others at the Car- 

 lisle, Pa., laboratory indicate that the species is probably a primary, 

 internal, solitary parasite of the spring generation of the fly, but 

 that it may occasionally develop as a secondary parasite. Little is 

 known regarding it, as attempts to breed it in the laboratory have 

 not been successful. Emergence is from the puparium of the fly. 



DISTRIBUTION 



Cheilonewrus elegans appears to be well distributed in Europe, 

 occurring, according to published records, in Great Britain, France, 

 Sweden, Germany, Austria, Switzerland, Italy, and Spain. 



In North America this species has been taken in the States of New 

 York, New Jersey, Pennsylvania, Maryland, Virginia, and the Prov- 

 ince of Ontario, Canada. Kecords of the Bureau of Entomology 

 laboratory at Carlisle, Pa., furnished by C. C. Hill, show it to be 

 present in at least 14 counties in Pennsylvania. Fewer records are 

 available from the other four States mentioned and only one from 

 Canada, probably because the parasites of the fly have been less 

 intensively investigated in those areas than in Pennsylvania. Enough 

 records are available, however, to indicate that the species is widely, 

 and perhaps generally, distributed throughout the Eastern States. 

 Apparently it does not yet occur in the Ohio and Mississippi Valleys 

 nor in the far Western States. 



IMPORTANCE 



This species can be rated as of only minor importance in relation 

 to hessian-fly control. According to Hill and Smith a yearly 

 average of 0.05 percent of the hessian-fly pupae collected in Virginia, 

 Maryland, and Pennsylvania over a 10-year period were killed by it. 



