Tufted thyatirine moth

Description

Tufted thyatirine moth is a common, medium-sized, false owlet moth. It occurs throughout most of the United States and southern Canada, but it is absent from the Great Plains and the Great Basin.

Adults are found in deciduous and mixed forests and in shrublands. They are active from May to October in other parts of their range, but all records from Minnesota are from mid-June to mid-August. They are active at night and will come to lights. The larvae feed on the leaves of a wide variety of hardwood trees and shrubs.

Adults are ⅞″ to 1″ (23 to 25 mm) in length and have a wingspan of 1½″ to 1¾″ (38 to 44 mm). Moth size is often given in terms of forewing length, which in this case is ¾″ to 13⁄16″ (20 to 21 mm). There are two color forms, the “typical” form and the “expultrix” form, and they are very different. According to one source in the “literature”, the typical form is "much more frequent.” An observer in Minnesota indicates that the expultrix form seems more common in their area. The two forms are about equally represented in photos on BugGuide.net and iNaturalist.org.

On the typical form, the forewing is fairly long, and it is pointed at the tip. It is medium gray with faint reddish brown tinting near the base, near the tip, and in the cell. There is a black patch at the anal angle bordered on the outer edge by a small tuft of cinnamon brown scales. This is the feature that gives the species its common name. There is a also a black patch at the base and another near the tip. The patch near the tip is divided by a narrow white line. The antemedial (AM) line is represented by three jagged, blackish lines that contrast sharply with the background. The postmedial (PM) line is similar but it extends only a short distance inward from the leading edge of the wing (costal margin). The terminal line is represented by a line of small black spots, a single dot or wedge-shaped mark at the end of each vein. The hindwings are gray.

On the expultrix form, the forewings are ashy gray with lighter pinkish shading near the base at the anal angle. There is also pinkish shading in the median area around the circular spot (orbicular spot) and the kidney-shaped spot (reniform spot). The forewing lacks the dark contrasting markings of the typical form.

Size

Total length: ⅞″ to 1″ (23 to 25 mm)

Forewing length: ¾″ to 13⁄16″ (20 to 21 mm)

Wingspan: 1½″ to 1¾″ (38 to 44 mm)

Similar Species

Habitat

Deciduous and mixed forests and in shrublands

Ecology

Season

June to September in Minnesota

Behavior

Adults are active at night and will come to lights.

The larvae are solitary feeders.

Life Cycle

Adult Food

Larva Hosts

A wide variety of hardwood trees and shrubs