|scientific name Acossus centerensis |
common name Poplar Carpenterworm
Mature woodland with poplar, in particular Trembling aspen.
Adults have been collected in Alberta from mid-June through early August.
A large (4.0-5.0 cm wingspan) heavy-bodied grey moth. The body is slate grey or blackish. Forewings are dark grey or black over the basal half, shading to lighter grey on the outer half, and are crossed by a network of fine broken black lines. The hindwings are thinly scaled and somewhat translucent white, with a very fine network of indistinct dark lines and a narrow black terminal line. Antennae are narrowly bipectinate in males, finely serrate in females. Sexes similar except for size, with females larger than males. The two-tone forewing with dark basal half and the pale hindwings will separate the Poplar Carpenterworm from the similar Carpenterworm (P. robiniae) and Aspen Carpenterworm (A. populi).
The larvae are borers that live in galleries they create in the trunks and stems of poplar trees, where they feed on the cambium area. Mature larvae are 4-5 cm long, creamy white with brown spots at the base of the setae, and dark brown heads and thoracic shields. Little is known about the life cycle, but the closely related Carpenterworm takes up to three or four years to complete the life cycle, and it is probable that the Poplar Carpenterwom also takes several years to mature. The adults come to light.
Larvae are occasionally been found when splitting aspen logs for firewood. Their boring can weaken trees, making them more vulnerable to wind damage and drought, but they are not abundant enough to be a serious problem.
At the northwestern edge of it's range in Alberta; no concerns.
The only Alberta data is for an adult reared at Altario from a larva in an aspen poplar (Populus tremuloides) log split for firewood. They probably also utilizes other poplar species as well.
Eastern North America, west to central Alberta. In Alberta, they have been collected along the southern edge of the Boreal forest (Lac la Biche, Redwater and Edmonton areas) and in the Aspen Parkland (Altario).
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