July 1893. 



PSYCHE. 



491 



A CABBAGE-LIKE CECIDOMYIIDOUS 

 GALL ON BIGELOVIA. 



BY C. H. TYLER TOWNSEND, 

 KINGSTON, JAMAICA. 



On June 21, 1892, a small bud-like gall was 

 found on Bigelovia graveolens. It was quite 

 abundant a few miles to the east of Gallo 

 Spring, N. Mex. There were also found next 

 day, June 22, west of Apache Spring. 



Gall. — Length, 5 to SJ mm. ; greatest basal 

 width, 4 to 7 mm. Small, bud-like, borne on 

 sides of stems, to which the gall is attached 

 by a very constricted base almost without 

 length ; formed of loosely overlapping stip- 

 ules much like the cabbage gall on willow 

 but not conical or compact. Greenish in 

 color, or slightly yellowish, scantily covered 

 with a fine white woolly pubescence. Stip- 

 ules forming the gall rather broad at base, 

 pointed at end or sometimes rounded, from 

 12 to 20 in number, but not more than 8 or 10 

 showing on the outside, the tips of the rest 

 joined and forming the terminal central tip of 

 the gall. Inside the innermost of these, in a 

 little slightly hardened cell, a single larva or 

 pupa is found. Stipules with the woolly 

 pubescence on the outer convex surface and 

 on the edges, nearly or quite bare on the 

 inner concave surface! The central pupal 

 cell is thinly lined with the white woolly 

 pubescence, and is about 3 mm. long, by \\ 

 mm. wide. 



Described from 8 or 9 galls. This species, 

 which is with hardly a doubt new, may be 

 called Cecidomyia bigeloviae-brassicoides. 



Mr. T. D. A. Cockerell records, on page 

 106 of vol. vi, West American Sci., the breed- 

 ing of a cecidomyian from the galls of the 

 trypetid Eurosta bigeloviae. If bred from the 

 trypetid galls, it can hardly be the same as this 

 species. He proposes the name C. bigeloviae 

 for it, but without description of either gall or 

 insect. 



The click of Ageronia. — In a paper 

 on stridulation in certain Lepidoptera pub- 



lished by the Zoological society of London 

 Mr. G. F. Hampson gives the first reasonable 

 explanation of the clicking sound produced 

 by Ageronia. He says :"On detaching and 

 clearing a fore wing of Ageronia arethusa. I 

 found there was a small pyriform membran- 

 ous sac attached to the base of the inner mar- 

 gin of the fore wing, open anteriorly, and 

 with a pair of curved chitinous hooks with 

 spatulate extremities lying freely in front of 

 it. It was obvious that this could not come 



into contact with any of the nervures of the 

 hind wing, and that no structure attached to 

 the hind wing could act on it; and as there 

 seemed to be a projection on the thorax in 

 the immediate neighborhood, I cleared and 

 denuded of scales a half insect with the wings 

 still attached to the thorax, and could then 

 see under a low power of the microscope that 

 there was a pair of strong chitinous hooks 

 attached to the thorax and that when the fore 

 wing was moved up and down the spatulate 

 ends of the chitinous hooks attached to the 

 wing played against these, being released 

 when the wing reached a certain angle, and 

 I suggest that this is the cause of the clicking 

 sound, the hooks acting as a tuning fork 

 and the membranous sac as a sounding 

 board." We owe to the favor of the Zoolog- 

 ical society the opportunity to reproduce 

 here his cut illustrative of the mechanism 

 involved. 



Early appearance of Anosia plexip- 

 pus. — On two very warm days in the early 

 part of May, May 11 and 12, Mr. S. W. Den- 



