96 university of colorado studies 



Tribe Xeriini 



Hind tibiae with one calcar; humerus and transverse median of the hind wings 

 wanting. 



Genus XERIS Costa 



Ovipositor longer than the abdomen; antennae long; slender; apical plate of the 

 abdomen long, spear-shape; only one brachial vein. 



(4) X. caudatus (Cresson). Black; legs ferruginous; spot on posterior orbits, 

 and lateral dorsal angles of pronotum white; wings hyaline, somewhat dusky, venation 

 dark brown. 



One female collected on Arapahoe Peak (above timber-line). September 1 (S. A. 

 Rohwer). 



Subfamily TREMICINAE 



Cerci wanting; antennae short and stout; basal vein and transverse median vein 

 interstitial or nearly; second transverse cubitus wanting. 



The larvae of this subfamily confine their attacks to deciduous trees. 



Genus TREMEX Jurine 

 Characters of subfamily. The species of this genus are parasitized by Megarhyssa 

 lunalor. 



(5) T. columba var. sericea (Say). 



Boulder, Colorado, August 27, 1907, one male at flowers of Helianthus pumilus 

 (S. A. Rohwer). This is the pale form agreeing with Say's description of sericea. 



Superfamily Tenthredinoidea 



Posterior margin of the pronotum strongly arcuate; mesonotum extending much 

 beyond the anterior margins of the tegulae; metanotum present; antennae inserted 

 well above the clypeus; anterior wings with more than two cubital cells; scutellum never 

 completely separated from the mesoscutum, the suture always wanting laterally; anterior 

 tibiae with two calcaria; proepimeron present; cubitus joining the costa or touching the 

 basal vein very close to the costa. In all Boulder County species the first perapterum 

 and notauli are always present. 



The larvae of this superfamily have diverse habits, but with exceptions of the leaf- 

 miners and the gall-makers are external feeders. This is the group commonly called 

 "sawflies," and contains all of the common sawfly pests. 



Family ARGIDAE 



Abdomen not sharply angled laterally; antennae not clavate; sternali (a suture 

 separating the mesosternum from the mesoepisternum) present; posterior coxae con- 

 tiguous, or nearly so; antennae three- jointed; proepisternum not divided. 



Subfamily STERICTIPHORINAE 



Fore wings without an intercostal vein; antennae of the male furcate; hind tibiae 

 without lateral spurs. 



The larvae of Sterictophinae are very imperfectly known in North America. Two 



