April, '10] KELLY : EUPELMUS AND STICTONOTUS 203 



eggs into the cells of Isosoma larvtp, but not always on the larva itself ; 

 and inside the puparium of the Hessian ^y, but, again, not into the 

 larva. 



Life History. During the early fall the egg hatches in three to 

 six days, after deposition the tiny larva attaches itself to the host 

 larva and sucks its life blood; they do not consume the skin of the 

 host. The larvae reach maturity in six to fifteen days and pupate in 

 the Isosoma cell witliin the straw, and within the puparium of the 

 Hessian fly. The pupa? are naked in both species. The pupal period 

 ranges from seven to twelve days. 



Eupelmus allynii hibernates in both the larval and pupal stages. 

 Stictonotus isosomatus liibernates as pupa. Both species are found 

 in cells of Isosoma sp. and in puparite of Hessian fly at this date 

 (November 26, 1909). There were two distinct broods this year — 

 one in early summer, the other in fall. 



Descriptions. The eggs of the two species are quite difl^erent ; 

 that of Eupelmus is whitish in color and pedicellate. The bulb is 

 elliptical in form, about .25 mm. in length and .12 mm. in width ; the 

 pedicel is slender, of imiform diameter and nearly as long as the 

 bulb. The egg of Stictonotus is whitish in color, elliptical in form 

 and about .3 mm. long and .12 mm. in width. 



The lar^^ae of the two species, though quite similar when viewed 

 without the aid of a magnifier, magnified they present some striking 

 differences. Eupelmus larva? have four distinct rows of bristles on 

 the body, each segment having two dorsal and two ventral; the head 

 bears two tiny brown mandibles; they vary in size from 2 to 4 mm. 

 in length. Stictonotus lurx-x are more cylindrical, have no bristles 

 and no mandibles; they are 2 to 4 mm. in length. Both species are 

 yellowish white in color. 



The pupfe are quite different, Eupelmus being black with light 

 rings on the abdomen, while Stictonotus has a dark thorax and yel- 

 lowish abdomen. 



A very interesting feature of parasitism presented itself while 

 these studies were in progress. Eupelmus allynii lavwe were found 

 attached to pupse of Stictonotus isosoinatis and reared to adult; and 

 Stictonotus isosomatis larva were found attached to pupae of 

 Eupelmus allynii and reared to adult. Parasitic larva were found 

 attached to parasitic larvae whose identity could not be determined 

 because of mutilation or because of the desire of the writer to rear 

 the secondary parasite. However, both species were reared from 

 these laiwae, the host not being determined. In several instances ter- 

 tiary parasites were found but failed to mature. 



