176 



PSJ-CHE. 



[December 1S94. 



A CONE-LIKE CECIDOMYIID GALL ON BIGELOVIA. 



BY C. H. TVLER TOWNSEND, LAS CRUCES, N. MEX. 



A cone-like cecidomyiid gall was 

 found on Bigelovia graveolens, near 

 Gallo Spring, N. M., June 21, 1S92. 

 They were also found west of Apache 

 Spring and the Rio Apache, June 22. 

 One of the latter, opened on that date, 

 revealed three small larvae which were 

 apparentl}' cecidonij-iidan. Both the 

 above localities are in western Socorro 

 County, New Mexico. This cecido- 

 myiid may be known as Cecidomyia 

 b igel oviae-st rob ilo ides. 



Gall. — Leimth, S to 10 mm. ; width 3 to 

 6 mm. Rather elongate, siibcjlindrical in 

 general form, but little nanower on apical 

 than on basal portion. Borne on side of 

 twig, to which it is attached by a short 

 and narrow stem. Rather compact, formed 

 of many narrowed overlapping stipules, 

 but these are apparently united and grown 

 together, forming a compact body, only 

 the terminal elongate portions of the outer 

 stipules free and showing as curled tips 

 on the outside of the gall. The stipules 

 arranged like the cone of a pine tree, all 

 extending nearly upward but slightly out- 

 ward from the central longitudinal cell. 

 Outside of gall covered with a thin white 

 woolly pubescence, the gall greenish beneatli 

 this, and the rather long narrow more or 

 less curled free terminal ends of stipules 

 protruding through the wooUiness, and 

 growing more numerous toward tip of gall. 

 The central cell is from 4 to 5 mm. long, 

 I mm. wide, quite cylindrical, its walls a 



little hardened in texture. It does not 

 extend to base of gall. 



Described from three galls; one alco- 

 liolic and two dried specimens. About 

 the middle of August, 1S92, the pill 

 box containing the two dried galls 

 was opened and found to contain a 

 metallic dark green microhymenop- 

 teron with an ovipositor as long as its 

 body. It is a minute species. LIpon 

 opening one of tlie dried galls, several 

 very minute transformed hymenopter- 

 ous parasites were found in the terminal 

 portion of the cell, and a well-formed 

 cecidomyiid pupa wit'i very long leg 

 sheaths found in the basal portion. 

 As several larvae appear to inhabit the 

 single cell in each gall, the minute 

 parasites probably developed in the 

 other cecidomyiid larvae leaving one 

 untouched to transforrn. The minute 

 parasites were without ovipositor and 

 are doubtless males of the above men- 

 tioned species. The other dried gall, 

 which was the smallest one, contained 

 the skin of a cecidomyiid pupa and 

 transformed female of the above micro- 

 hymenopteron. This iiymenopterous 

 parasite has been determined by Mr. 

 Wm. H. Ashmead as Torvimis sp. 

 It is a little over i mm. in length 

 (9), with nearly clear wings. Ovi- 

 positor a little over i inm. 



Recent numbers of the Kansas University head of Danais archippus," and "the taxono- 



Quarterly have contained valuable papers on mic value of the scales in Lepidoptera," and 



the anatomy of Lepidoptera. Vernon L. now appears an excellent study of ''the pro- 



Kellogg has discussed "the sclerites of the thorax of butterflies," by May \\. Wellman. 



