F-500805 
Figure 55.—Larva of the boxelder twig borer, Proteoteras 
willingana, in a boxelder stem. 
The spruce bud moth, Zeiraphera canadensis Mutuura & Freeman, occurs 
throughout the range of spruce in the Northern United States and Canada (984). In 
addition to spruce, it feeds on several other conifers, especially fir. The adult is 
light brown and has a wingspread of about 14 mm. The forewings have darker 
diagonal markings, and the outer margins are straight. Full-grown larvae are 
yellowish or grayish green and about 18 mm long. 
Young larvae feed singly in opening buds in the spring or on tender terminal 
needles which they web together. Some pupae are found on the foliage of the trees, 
but the majority occur immediately below the ground surface. Winter is passed in 
the egg stage, and there is one generation per year. Z. improbana (Walker) occurs 
all the way across southern Canada and possibly in the northern tier of States. It 
appears to prefer larch and spruce, but several other conifers are also infested. The 
foregoing two Zeiraphera species were formerly thought to be European but now 
they are shown to be specifically distinct from their European counterparts (900). 
Z. unfortunana Powell occurs commonly from coast to coast in southern Canada. 
Infestations also have been found in Maine. It apparently prefers white spruce. 
The maple trumpet skeletonizer, Epinotia aceriella (Clemens), occurs from 
southern Canada to North Carolina. Its hosts are principally red and sugar maples, 
but it has also been collected on hawthorn and beech. The adult is white with 
dustings of gray or brown, and has a wingspread of about 15 mm. Each larva spins a 
long trumpetlike tube of silk and frass on the underside of a leaf, causing the leaf to 
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