Fingered Dagger

Appearance

The wingspan is 45–55 mm. Adults are on wing from May to July in one generation depending on the location.

Adult: Powdery gray FW with darker markings and whitish HW. FW with the normal markings somewhat broken and blurred, the outer part of the PM and a partial reniform spot most prominent. The orbicular spot is a small, hollow ring. There is no basal dash. The anal "dagger mark" is blurred but obvious. The male hindwings are white with grey scales along the veins. The female is larger and is more heavily dusted with grey on the hindwings. Antennae in both sexes are simple.

Larva: body covered with stiff orange or brown hair dorsally, and pale yellowish or white hair laterally, with several much longer black hairs and white hairs concentrated near the front and back (may also have three dense dorsal tufts of long black hair on abdominal segments 1, 3, and 8)

Naming

''Acronicta hesperida'' was formerly considered to be a separate species, but is now considered a synonym.

Acronicta insita (Walker, 1856)
Acronicta dactylina (Grote, 1874)
Acronicta hesperida (Smith, 1897)

Large, pale, poorly marked adults of western populations were previously considered a separate species (Acronicta hesperida).

Distribution

Newfoundland to North Carolina mountains, west to Manitoba and Illinois.

Status

Uncommon, but widely distributed.

Food

Larvae feed on alder, birch, poplar, hawthorn, willow.

Defense

They have fine hairs that are actually hollow, containing a toxin within. If direct contact is made through handling or even indirect contact through clothing, shaking a tree branch with a alder dagger caterpillar on it can result in exposure to these fine hairs. Mild to severe rashes may appear for up to a week and may spread easily to other areas of the body through clothing rubbing on exposed area or scratching. Some people react more seriously while others have no reaction at all. Applying strong adhesive tape to the area immediately after exposure may help to remove the fine hairs from your skin/clothes.