|scientific name Catocala relicta Wlk.|
common name White Underwing, The Relict
Mature hardwood and mixedwood forest, in particular aspen forest.
Adults are on the wing from late July through September.
A large (6.7-7.5 cm wingpan) moth with white forewings crossed by several diffuse black bands and lines, the most prominent being the median band. The hindwings are jet black with a white median band and a narrow white terminal band and fringe. The amount of dark scaling on the forewings varies greatly among populations. The antennae are simple and the adults look alike. Unmistakable.
Adults are nocturnal and come to light, but they are best collected using sugar baits. The adults emerge in late summer and early fall, and the eggs overwinter. The larvae, which are solitary defoliators, hatch in May and can be found until early August. There is one brood per year.
A common, widespread insect. No concerns.
No Alberta data. Elsewhere in Canada the larvae feed mainly on Aspen poplar (Populus tremuloides). Also reported, much less frequently, from Balsam poplar (Populus balsamifera), willow (Salix) and White birch (Betula papyrifera).
Across southern Canada, from Newfoundland to Vancouver Island, south to Missouri and Arizona. In Alberta, it is found throughout the Aspen parklands, southern Boreal forest north to the northern Peace River area, and the foothills and lower elevations in the mountains. It is also present in smaller numbers in cottonwood stands along the rivers of the grasslands region (Dinosaur Provincial Park and Lethbridge).
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