pale beauty

not listed

NNR - Unranked

SNR - Unranked

not listed

Pale beauty is a common, medium-sized, typical geometer moth. In the United States it occurs in the east from Maine to northern Georgia, west to Minnesota and northern Arkansas; on the West Coast from northern Washington to central California; and along the Rocky Mountains from Montana to New Mexico. It is absent from the Great Plains, the desert west, and the deep south. It also occurs across Canada from Newfoundland and Labrador to Yukon (the name of the province was officially changed from “the Yukon” to simply “Yukon” in 2003) and in Alaska. In Minnesota it is common in the eastern half of the state, mostly absent from the western half.

Pale beauty is found from early June through early September in deciduous, coniferous, and mixed forests, and in shrubby areas. Larvae are generalist feeders. They feed on the leaves of at least 65 species of trees and shrubs, including alder, ash, basswood, beech, birch, blueberry, cherry, cranberry, fir, elm, hemlock, maple, oak, pine, poplar, rose, spruce, tamarack, and willow. Adults have nonfunctional mouth parts and do not feed.

Adults have a 1⅛″ to 2″ (28 to 51 mm) wingspan. The female is much larger than the male.

The wings are translucent and are tinged to varying degrees with some shade of green. On the forewing, the antemedial (AM) line is white with a dark lower shadow, and the postmedial (PM) line is white with a dark upper shadow. Both lines are relatively straight and curve upward near the leading edge (costal margin). The PM line continues onto the hindwing, the AM line does not. The wings are otherwise unmarked. The fringe is pale.

The antennae on the female are slender and thread-like. On the male the antennae are branched, feather-like, on both sides (bipectinate).

The caterpillar, called fringed looper, is up to 1½″ (4 cm) long. The ground color may be gray, brick red, or occasionally smoky green. On the sides of the body the breathing pores (spiracles) are ringed with black. The underside of the body is noticeably flattened and pale. Most caterpillars have a pair of fleshy, leg-like structures (prolegs) on abdominal segment three (A3) through A6 and another on A10. Pale beauty has an extra set of prolegs on A5. On each side of the body there is a fringe of thickened pale hairs at the bottom. The fringe probably makes the caterpillar more difficult for predators to see.

Wingspan: 1⅛″ to 2″ (28 to 51 mm)

Deciduous, coniferous, and mixed forests; shrubby areas

Two generations per year in Minnesota: June through early September

Adults are active at night and will come to lights. They spend the day on the underside of living leaves. They rest with their wings spread out.

Third or fourth stage (instar) caterpillars overwinter on tree bark and on branches, probably fully exposed.

At least 65 species of trees and shrubs, including alder, ash, basswood, beech, birch, blueberry, cherry, fir, elm, hemlock, maple, oak, pine, poplar, rose, spruce, tamarack, and willow

Sources

4, 21, 24, 27, 29, 30, 71, 75, 82, 83.

Location: Whitewater State Park, along the Trout Run Creek Trail