SEKPHOID AND CHALCIDOID PARASITES OF THE HESSIAN FLY 17 



that outlined b} r Herrick. It is probable that Cook's observation re- 

 garding oviposition involved more than one species, since the state- 

 ment that more than one egg is deposited in a single host egg is ap- 

 plicable to Memalis but not to the species which was sent Packard 

 and which was described by him. In 1885 Kiley figured the species 

 and, being convinced that it was different from error, adopted for 

 it the name Packard had suggested. Forbes (1888) mentioned it in 

 pointing out the characters distinguishing it from Memalis. 



In his monograph of the proctotrypids in 1893, Ashmead redes- 

 cribed herrichii and synoymized with it Aneurynchus aneurus Pro- 

 vancher. This synonymy was based by Ashmead upon examination 

 of a male specimen sent to him by W. H. Harrington and labeled 

 " type." This specimen is in the National Museum collection and it 

 is herrickii, but it cannot be the Provancher type because the species 

 was described from a female, no mention being made of a male, and 

 also because it does not agree with the description. It certainly is 

 not the species described by Provancher. which is said to have the 

 antennae 13- jointed and inserted on a transverse prominence on the 

 middle of the head, the thorax polished and shining, and the legs 

 honey-yellow. None of these characteristics agrees with P. herrichii, 

 and the Provancher species is therefore dropped from the synonymy. 

 Provancher's species probably belongs in the Diapriidae. but only ex- 

 amination of the type will permit it to be placed generically. 



Platygaster herrickii has received mention by numerous authors 

 since x4shmead, very few of whom have contributed any new infor- 

 mation other than records of distribution and abundance. 



HOSTS AND LIFE HISTOEY 



Platygaster herrichii is a primary, internal, solitary parasite of 

 Phytophaga destructor and so far as known has been reared from no 

 other host. Adults appear in early spring (February, March, and 

 April are indicated by the labels on specimens in the National Mu- 

 seum collection) and attack the spring generation of the fly by laying 

 a single egg in the egg or in the very young larva of the host. The 

 parasite larva does not destroy its host until after the latter has 

 formed its puparium. It then devours the contents of the puparium 

 and forms its cocoon within the empty shell. Complete details 

 of the development of this species are not known. 



DISTRIBUTION 



Platygaster herrickii occurs generalty throughout most of the 

 wheat-growing region of the United States from the Atlantic to the 

 Pacific, and from New York to North Carolina. So far as is known 

 to the writer, it has not been recorded from California. The single 

 male specimen already mentioned as having been sent by Harrington 

 to Ashmead under the name Aneurynchus aneurus, and probably 

 collected somewhere in Ontario, is the only Canadian material of the 

 species seen. Specimens from Niagara, N.Y., and Battle Creek, Mich., 

 however, indicate the possibility that the species may be more common 

 in eastern Canada than the records imply. 



The species was doubtfully recorded from England by Ormerod 

 in 1887 and by Enock in 1888. These records have been copied by 



6685°— 33 2 



