|scientific name Paranthrene robiniae |
Montane and adjacent boreal deciduous woodland.
Adults have been collected in Alberta in June.
A relatively large clearwing moth (2.7-4.0 cm wingspan) with the forewings mostly scaled with rusty olive brown scales and the hindwings hyaline. The head and thorax are dark, with yellow or orange markings. The first two or three abdominal segments are dark, with a single narrow yellow band, and the remainder are usually entirely yellow or rust-red. The forewings are mostly covered in scales, with an indistinct, broad oblique “discal mark”, and with a partially unscaled or very lightly scaled area just beyond, forming a light oblique stripe or streak. The legs are pale yellow or orange. All Alberta specimens seen are form perlucida (Busck), a much redder form than the nominate form. P. tabaniformes (Rottemburg) has been recorded from Manitoba and Saskatchewan, and should be watched for in eastern Alberta. It is similar is size to P. robiniae, but has a white front to the head (yellow or orange in robiniae) darker blackish and more heavily scaled forewings and a black abdomen with three or four narrow yellow bands.
P. robiniae larvae bore in the exposed roots, stems and branches of poplar and willows, in particular in weakened or damaged smaller trees and low growing willows. They may also be destructive in ornamental plantings of birch. The mature larvae spend the second winter of their two-year life cycle in pupal chambers constructed in the upper part of their tunnels, with pupation occurring in spring and adults emerging in late spring and early summer.
An uncommon but widespread species; no concerns.
Borers in poplars (Populus sp.), willows (Salix sp.) and occasionally in birch (Betula).
Paranthrene robiniae is a western species closely related to the eastern P. tabaniformes (Rottemburg). It is found mainly in the mountains, from the Rocky Mountains west to the coast, south to the southwestern deserts and north to Alaska. There are several records from Edmonton and Calgary, as well as the Crownest Pass area.
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