IOO UNIVERSITY OF COLORADO STUDIES 



delta is the dominating one in the west. The adults are more numerous in mid-summer 

 and may often be collected in great abundance on the flowers of Heracleum lanatum. 

 The length of life of the adults is not known, but it is known that they are either herbiv- 

 orous or carnivorous. Only the tribe Tenthredinini has been found in the county, 

 although the Perineurini may be represented by the genus Zaschizonyx Ashmead. 



Tribe Tenthredinini 



Propodeal spiracle placed at, or near, the lateral dorsal basal angle of the propodeum; 

 anterior margin of the scutellum truncate or nearly so, its cephal-caudad length much 

 shorter than the width. 



Genus TENTHREDELLA Rohwer 



Mesial margins of the eyes strongly converging below; space between the eyes at the 

 antennae less than the length of the eye; malar space very narrow; metaepimeron narrow; 

 not rectangular in outline, curved above, reaching to, or very little beyond, the propodeal 

 spiracle; hind coxae normal; nasal margins of the antennal sockets strongly dilated and 

 hollowed out between; the antennae often longer than the head and thorax, 9- join ted, 

 not thickened apically. 



This genus will probably be well represented in the county as there are many species 

 known from Colorado. They are boreal and are often found in numbers on the flowers 

 of Heracleum lanatum. 



One species (allied to pectoralis Norton) has been taken at Copeland Park, Boulder 

 County, Colorado, on September 6, 1907, by G. M. Hite. 



Subfamily MESSINAE 



Prepectus wanting; proepisternum very small ventrally, and widely separated; 

 presternum T-shaped; metapostnotum short; mandibles short, not strongly falcate; 

 robust, short species; basal vein and first recurrent vein strongly diverging; the first 

 recurrent vein much shorter than the basal vein. 



Tribe Phyllotomini 



Anal cell of the fore wings contracted basally and with an oblique cross-vein. 



Genus CALIROA O. Costa 

 Antennae 9- jointed; inner margins of eyes parallel. Larvae slimy, slug-like; 

 skeletonizing leaves of shrubs and trees. 



Subgenus CALIROA O. Costa 



Clypeus truncate; pedicellum much wider than long, shorter than the scape; hind 

 wings of female usually with only one discal cell. 



(14) C. aethiops (Fabricius). The adults of this species have not as yet been taken 

 in the county, but their work on rose leaves is not uncommon. For an account of the 

 larvae and a summary of the habits, see Chittenden, 1903, p. 1. 



Subgenus ERIOCAMPOIDES Konow 

 Clypeus emarginate; pedicellum subequal in length with the scape; hind wings of 

 the female usually with two discal cells. 



