SMICRONYX WEEVILS—ANDERSON 297 
laterally and medially behind antennal insertions, punctate and 
sometimes feebly carinate before antennal insertions, in male; 
only traces of carinae behind antennal insertions, smooth, finely 
punctate before antennal insertions in female. Head black, finely 
alutaceous, thinly squamose above antennal insertions. Prothorax 
black, moderately rounded at sides, narrowed some distance 
behind apex; punctures deep, rounded, closest medibasally where 
interspaces form short transverse rugae; scales light brown with a 
scattering of gray, mostly ovate and subtruncate, a few linear and 
pointed. 
Elytra black to piceous; humeri distinct, subangular; scales, 
except usual setiform scales, ovate, white, gray, or light brown, so 
arranged that brown scales form indistinct, wavy bars. Underside 
of thorax and abdomen black, closely covered with small, ovate, pale 
gray scales. Femora rufous, moderately clavate, covered with small, 
elliptical white scales. Tibiae rufopiceous, covered with linear, white 
scales. Tarsi rufopiceous, third segment distinctly broader than 
first two; fourth segment considerably exceeding third, claws connate 
near their bases, moderately divergent. Median lobe of male geni- 
talia gradually broadened toward apex, internal sac rather granulate 
near median orifice, covered with fine spines elsewhere (fig. 81). 
MeEasurEMENTS: The following measurements were taken from 
3 male and 3 female topotypes from Regina, Sask. (USNM, CNC) 
and 1 male and 2 female paratypes from Regina, Sask. (USNM). All 
measurements are in millimeters: 
Males Females 
Mean Extremes Mean Extremes 
Body length 2. 40 2. 00-2. 70 2.56 2. 30-2. 70 
Elytra length 1. 35 1. 30-1. 90 170) 0) Leo0-12 90 
Elytra width at base 0. 95 0.°76=1. 12 0.99 0. 86-1. 09 
Prothorax length 0. 57 0. 49-0. 66 0.60 0. 59-0. 66 
Prothorax width 0. 67 0. 56-0. 76 0.68 0. 59-0. 76 
Rostrum length 0. 85 0. 79-0. 96 0.96 0. 79-1. 03 
Rostrum length before anten- 0. 29 0. 26-0. 36 0.41 0. 33-0. 46 
nal insertion 
Funicular segment 2 length 0.063 0. 051-0.068 0.076 0. 068-0. 085 
Funicular segment 3 length 0. 034 0.050 0. 034-0. 051 
Brotocy: Rempel and Shevkenek (1941) made a study of the bi- 
ology of S. utilis in Saskatchewan. A summary of their findings 
follows. 
The only known host plant of this weevil is poverty weed, Iva 
axillaris Pursh. The adult weevils appeared on the plants in early 
June, when the poverty weed began to blossom. Copulating pairs 
were first noted about June 10, and the first oviposition was noted 
about June 20. In ovipositing, the females chewed circular holes 
through the bracts of the involucres of the flower heads and into the 
586455—62——_8 
