|scientific name Clostera albosigma |
common name Sigmoid Prominent
In Alberta adults are on the wing from the first week in May through mid-August.
Deciduous woodland and shrublands.
A medium-size (2.8-3.8 cm wingspan) grey-brown or brown moth with short bipectinate antennae and a characteristic tuft on the tip of the abdomen in males. The forewing is crossed by four fine pale lines, much more prominent in spring than in summer specimens. The apical quarter of the wing is dark chocolate or red-brown, sharply delineated from the remainder of the wing and separated at the costa by a short curved white bar. It can be separated from other Clostera species by the sharp demarcation of the dark apical patch on the forewing. It most closely resembles the smaller and darker Clostera brucei, which lacks the sharp contrasting separation of the dark apical area from the rest of the forewing. Spring specimens which are paler and marrked be a series of pale lines have been named form specifica; summer specimens are darker and more uniform in color and pattern. Sexes are similar, but female antennae are simple. See also Clostera apicalis.
Adults are nocturnal and come to light, but are not attracted to sugar baits. The larvae are solitary leaf folders. The extended flight period suggests more than a single brood, but this needs to be documented.
A common, widespread species; no concerns.
Canadian data, which includes Alberta data, lists various poplars (Populus) and willows (Salix), with Aspen poplar (P. tremuloides) by far the most prevalent host.
Newfoundland west to Vancouver Island, north to Great Slave Lake, Northwest Territories and south to at least Missouri. In Alberta they occur throughout most of the wooded parts of the province north to Zama. Uncommon in the wooded valleys of the grasslands region.
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