Anisota

Hübner, 1820

Oakworm Moths, Oakworms

Anisota is a of giant in the , first described by Jacob in 1820. Their are commonly known as due to their specialized feeding on oak foliage. The genus contains approximately 13 distributed across North America, including well-known species such as the orangestriped oakworm (A. senatoria), pink-striped oakworm moth (A. virginiensis), and spiny oakworm moth (A. ). are gregarious feeders and can cause noticeable of oak trees, particularly in late summer.

Anisota stigma by (c) John P Friel, some rights reserved (CC BY), uploaded by John P Friel. Used under a CC-BY license.

Anisota by (c) Christine Young, some rights reserved (CC BY), uploaded by Christine Young. Used under a CC-BY license.

Anisota by (c) 116916927065934112165, some rights reserved (CC BY), uploaded by 116916927065934112165. Used under a CC-BY license.

Pronunciation

How to pronounce Anisota: //æˈnɪsətə//

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Identification

Anisota are to large-sized Saturniids with furry bodies and relatively subdued coloration compared to other moths. Males have broadly feathery ; females have less-feathery, more thread-like antennae. are distinctive: most have prominent longitudinal stripes (orange, pink, or depending on species) and paired fleshy horn-like behind the . The orangestriped (A. senatoria) has black and orange banding; the pink-striped oakworm (A. virginiensis) has pink stripes; the spiny oakworm (A. ) has prominent branched .

Images

Habitat

Oak-dominated forests and woodlands, including urban and suburban landscapes where oak trees are present. are found on foliage of oaks; are often attracted to lights. Some occupy specialized —A. finlaysoni is restricted to alvar habitats (limestone plains) of the Great Lakes region.

Distribution

North America, with ranging from southern Canada through the eastern and central United States. A. senatoria occurs throughout eastern North America; A. virginiensis ranges from the Great Lakes region to Florida and Texas; A. occurs in the eastern and central United States; A. finlaysoni has a restricted range in eastern Ontario; A. oslari occurs in the southwestern United States including Trans-Pecos, Texas.

Seasonality

emerge in spring and summer, with timing varying by and latitude. In Maryland, A. senatoria adults first appear in May from , with a second producing adults later in summer. Late-season by is most conspicuous from July through September.

Diet

feed exclusively on oak foliage (Quercus spp.), with some also recorded on hickory (Carya) and birch (Betula). Specific associations include: A. oslari on sandpaper oak (Quercus pungens var. vaseyana); A. senatoria on various oak species including pin oak (Q. palustris). do not feed.

Life Cycle

with one to two per year depending on and location. Females lay on undersides of leaves. feed gregariously, initially skeletonizing leaves, later consuming entire leaves except major . Mature larvae drop to the ground, burrow into soil to pupate, and overwinter as . emerge the following spring to mate and oviposit.

Behavior

are gregarious, feeding in clusters that can cause localized heavy . When disturbed, may regurgitate or thrash. Mature larvae exhibit mass exodus , dropping from trees and crawling across ground surfaces to find sites—this makes them vulnerable to mortality on paved trails and roads. are and attracted to light.

Ecological Role

function as primary consumers of oak foliage, transferring energy from trees to higher . They serve as for numerous (ichneumon , wasps, ) and (birds, , predatory ). typically regulate , causing collapses. production contributes to in forest .

Human Relevance

are occasionally significant defoliators of landscape and street trees, causing aesthetic damage and concern. have prompted programs in such as Norfolk, Virginia and Montgomery Village, Maryland. Mechanical removal of larval clusters or targeted (, ) are used when management is warranted. Late-season rarely causes lasting tree damage.

Similar Taxa

Dryocampa rubicunda (greenstriped mapleworm)Also a with similar and late-season , but feeds on maple (Acer) rather than oak; have green and stripes rather than orange or pink
Lochmaeus spp. (tussock moths)Late-season oak defoliators with gregarious , but have distinctive tussock hairs and different
Datana spp. (handmaid moths)Gregarious that feed on oaks and other , but have smooth bodies with longitudinal stripes and different resting posture (rear end raised)