Triton Dagger Moth

Very rare and at the extreme northwestern limit of its range in northern Alberta.

The only Alberta record is an adult female collected in mid-June.

Nova Scotia west to northeastern Alberta, south to Florida and Texas, and in the USA west to Oregon. In Alberta, known only from a single specimen collected just north of Fort McMurray.

A medium-size (3.5-4.0 cm wingspan) dark purple-grey moth. Forewings have a long narrow black basal streak, a larger black streak (dagger-mark) in the anal angle, and a smaller one near the apex. The postmedian-line is prominent, marked with black scales, and loops outward between the costa and the upper dagger mark, between the two dagger marks, and below the lower dagger mark. The orbicular spot is indistinct, marked by a few dark scales. The reniform spot is more prominent and is filled with dark red-brown scales. There are also dark red-brown scales shading the upper part of the lower dagger-mark. Hindwings are grey-brown, darker toward the margin. The sexes are similar, but the female is darker, especially on the hindwings. Antennae simple in both sexes. The Triton dagger-moth is darker and less patterned than the other Alberta dagger-moths. Apharetra dentata is similar in color and pattern and occurs in the same habitat, but is much smaller and flies later in the season.

Dry forest with blueberry understory.

A solitary defoliator of blueberry. The single annual brood overwinters in the pupal stage. Adults come to light.

No Alberta data; elsewhere reported to feed on various Ericaceae, including species of Vaccinium sp. (blueberry and cranberry), Azalea and Rhododendron. The Alberta specimen was taken in association with blueberry.

Acronicta tritona, the Triton dagger moth, is a moth of the family Noctuidae. The species was first described by Jacob Hübner in 1818. It is found in eastern North America, from Nova Scotia west to north-eastern Alberta, south to Florida and Texas, and west to Oregon.

The wingspan is 35–40 mm.

The larva feeds on Helonias bullata and Vaccinium species, including Oxycoccos species and Vaccinium stamineum.