SEKPHOID AND CHALCIDOID PAEASITES OF THE HESSIAN FLY 21 



Telenomus. In 1906 Webster 6 republished the Comstock record of 

 p error from the clover seed midge in New York, and in 1916 Viereck 

 recorded the species from Connecticut, naming both the wheat midge 

 and the clover seed midge as hosts but failing to indicate from which, 

 if either, of these hosts the Connecticut specimens were reared. In a 

 revision of the North American Platygasterinae published in 1924, 

 Fouts redescribed the Fitch type and returned the species to the 

 genus Platygaster. Comstock's early record of P. error from the 

 clover seed midge was again cited by Wehrle 7 in an extensive treatise 

 on that midge in New York State published in 1929; but notwith- 

 standing the fact that Wehrle's investigations covered a period of 

 several years and included observations on the parasites, he failed 

 to rear P. error, but did rear two other species of Platygasteridae, 

 viz Platygaster leguminicolae Fouts and Inostemma legwninicola 

 Fouts. 



Ashmead was undoubtedly correct in assuming that the record by 

 Fitch of this species as a parasite of hemipterous eggs was a mistake 

 and that the parasite in question was a Telenomus. Fragments of a 

 Telenomus could easily have been mistaken by Fitch for a Platygas- 

 ter, and it is now well known that no Platygaster develops as a true 

 egg parasite. 



It is likewise almost certain that the record by Comstock of P. 

 error from the clover seed midge is another case of misidentification. 

 The species has not been recorded from this host since that time, 

 and this notwithstanding that Wehrle's above-cited investigations 

 were carried on in the same general locality as that from which the 

 Comstock record originated. It seems altogether likely that the 

 species involved in the Comstock record was Platygaster leguminico- 

 lae Fouts, a species very similar to error in many respects, and one 

 that easily might have been confused with it. 



HOSTS AND LIFE HISTORY 



Little is known of the life history of this species. Two specimens 

 are in the National Museum collection which were reared from pu- 

 paria of the wheat midge collected at New Castle, Pa,, by P. R. 

 Myers, emergence having occurred April 22, 1924. In the same col- 

 lection is a single broken specimen reared by Myers, January 19, 1915, 

 at Hagerstown, Md., from a puparium of the hessian fly. 



According to unpublished notes by Myers and R. M. Fouts, the 

 species occurred abundantly on the green heads of wheat at Mount 

 Holly Springs, Pa,, in 1920 and 1921 at about the time the grains 

 were filling, and numerous specimens were obtained by sweeping. 

 These observations agree with those made by Fitch in New York 60 

 years earlier, when he found numerous individuals on the wheat 

 heads late in June and in July. Several of the specimens swept by 

 Myers and Fouts have been examined by the writer, and they are 

 undoubtedly P. error. 



The date of appearance of the Platygasters in the field seems to 

 coincide rather closely with the date of egg laying by its host, and 

 it therefore appears likely that the egg of the parasite is deposited 



6 Webster, U.S.Dept.Agr.. Bur. Ent. Circ. 69: 5, 1906. 



7 Wehrle, N.Y. (Cornell) Agr. Expt. Sta. Bui. 481 : 29, 1929. 



