Figure 2. A, Breastbone of larva. B, Spines at caudal end of larva. C, Skin of larva. D, Gall.
On June 18, 1914, my wife and I found a hitherto undescribed gall on Stanleya glauca Rydberg, a remarkable cruciferous plant growing about four miles north of Boulder, Colorado. Thinking to rear the adults, the galls were placed in a bottle with some earth and watched for a long time, but nothing appeared. Supposing the effort to have been unsuccessful, I set the bottle aside; but long after discovered that adults had eventually emerged, but had died and were covered with mold. I was able to rescue sufficient fragments to make the drawings given herewith, which, together with the larval characters, serve very well to indicate the genus, with enough of the specific characters for ready recognition. The species may be called
Perrisia Stanleyae n. sp. (Cecidomyiidæ)
Gall: A swollen flower of Stanleya glauca, containing many pallid larvæ. The sepals are thickened and enlarged.
Larva: With the skin strongly verrucose; breastbone of the same general type as that of P. fructicola Kieffer; caudal end with strong spines.
Male: The characteristic genitalia and antennal joint are figured.
PROF. A. M. BEAN