Weevils - Entomological Society of Canada

Distribution. Quebec to Alberta; in the northern United States
from Oregon and Washington to New Jersey. Alberta: Bilby. Manitoba:
Treesbank. Ontario: Black Sturgeon Lake. Quebec: Choisy, Hudson
Heights, and Rigaud. Saskatchewan: Great Deer.
Comments. Adults of this species are most easily recognized by
the very diffuse color pattern, which is composed of white and very light
brown (almost white) setae in various configurations. Over a dozen
populations of this species have been described as separate species or
subspecies, including, according to Valentine (1971), all nine forms
named by Dethlefsen (1954). This synonymy has not been confirmed.
Nothing is known of the life history or habits of this species, except that
adults breed in the heads and stems of a variety of composite flowers,
especially various species of sneezeweed (Heleniurn species).
Trigo no rh i n us gflseus (LeConte)
Map 8
Brachytarsus griseus LeConte, 1876:405 (syntypes, Colorado;
MCZ).
Trigonorhinus griseus: Valentine 1957:9; Valentine 1960:58, 80.
Diagnosis. Length 2.7-3.5 mm (head excluded). Integument as in
T. limbatus. Setae on elytra bicolored; setae on interstriae 1-4 pale
yellow, yellowish white, or pale brown; setae on interstriae 5-7 white;
setae on interstriae 8-10 intermixed white and yellowish white.
Pronotum with white and yellowish white setae intermixed, with a more
or less distinct, narroq longitudinal stripe. Otherwise as in Z limbatus.
Distribution. Known only in Alberta and Saskatchewan.
Alberta: Lethbridge and Medicine Hat. Saskatchewan: St. Victor.
Comments. This species may be a particularly well-marked
variant of T. limbatus or a distinct species. Valentine (1960) records it as
a separate species, but in 1971 he does not mention the name, even
though the species occurs near the geographic area he treated. Adults of
this species are nearly identical to those of T. limbatus but may be
distinguished by the color pattern described above. Adults have been
collected on Colorado rubber plant (Hymenoxys richardsonii).
Genus O rmiscus Waterhouse
O rmi s cus Waterhouse, 1 845 : 3 7 I Valentine 7960 :62.
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