REPORT OF THE STATE ENTOMOLOGIST I916 



225 



stem of Muhlcnbergia m e x i c a n a. It was first reared 

 by Mr Marten at Champaign, 111., adults appearing from May 9 

 to June 10, 1902. There is but one generation annually, the larvae 

 wintering in the gall. We have received examples of this form from 

 Prof. Cyrus R. Crosby of Ithaca, N. Y., who reared the insect from 

 grass collected in that vicinity. 



Gall The gall has been described by Mr Marten 

 as cone-shaped and produced by the abortion of 

 a branch and the consequent approximation of the 

 leaves. He states that the peculiar yellowish larvae 

 lie singly or several together on the inner bases of 

 the leaves, thus producing the gall. 



The pupa he describes as reddish yellow, becoming 

 darker reddish or even orange color with age. When 

 ready to pupate, the old larval skin is pushed down 

 to the tip of the abdomen, where it remains adher- 

 ing to the last segment. 



The following descriptions have been drafted from 

 specimens kindly contributed by Prof. H. A. Gossard 

 of the Ohio Agricultural Experiment Station. The 

 anatomical characters are from these specimens, the 

 color features from Mr Marten's descriptions. 



Gall. Length about 3 cm, diameter nearly 1 cm. 

 This gall is a long, stout, fusiform swelling evidently 

 caused by the dwarfing of the young shoot leaves 

 growing close together and the larvae occur here and there at 

 base of the inner leaves. 



Larva. Length 2 mm, pale yellowish 

 white, breastbone not evident. The larvae 

 occur in numbers irregularly located between 

 the inner leaves of the gall. 



Female. Length 3 to 3.5 mm. Antennae 

 black, fading to dusky toward the tips, 

 yellowish brown basally; 19 segments, the 

 fifth with a length about one-half greater 

 than its diameter; terminal segment red- 

 dish, suboval. Palpi; the first segment 

 irregularly obconic, the second irregularly 

 conic, greatly swollen basally; face tinged 

 with yellowish brown and having a silvery 

 white reflection in certain lights ; it also has 

 a few scattering black hairs. Eyes rather 

 small, black. Mesonotum shiny pitchy black 

 with some reddish brown about the base of 

 the wings and on the posterior angles of the mesothorax. Scutelluni 

 black with reddish brown margins, somewhat transparent in appear- 

 ance; mctathorax and pleurae reddish brown, the latter with a 



Fig. 43 As- 

 ter o m y i a 

 a g r os t i s , 

 gall , natural 

 size (origi- 

 nal) 



the 



Fig. 44 Asteromyia 

 a g r o s t i s , palpus of 

 female, enlarged (origi- 

 nal) 



