Lochmaeus bilineata

(Packard, 1864)

Double-lined Prominent, double-lined prominent moth

Lochmaeus bilineata, commonly known as the double-lined , is a found across eastern North America. are active from spring through fall depending on latitude, with a wingspan of 32–40 mm. The feed on the foliage of several hardwood tree including Fagus, Quercus, Tilia, Betula, and Ulmus. As a late-season defoliator, it typically causes minor, localized damage that does not threaten overall tree health.

Lochmaeus bilineata by (c) brendanboyd, some rights reserved (CC BY). Used under a CC-BY license.

Lochmaeus bilineata by Jacy Lucier. Used under a CC BY-SA 4.0 license.

Lochmaeus bilineata P1250237a by
xpda. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Lochmaeus bilineata: /ˈlɒk.miː.əs ˌbaɪ.laɪˈniː.ə.tə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from similar by the paired dark longitudinal on the . The specific epithet 'bilineata' refers directly to this two-lined pattern. may be confused with other grey- , but the distinct parallel lines are diagnostic. are gregarious and found in clusters on foliage, which can aid in field identification.

Images

Habitat

Deciduous forests and woodlands containing tree . Associated with hardwood trees in both natural and urban settings where Fagus, Quercus, Tilia, Betula, or Ulmus occur.

Distribution

Eastern two-thirds of the United States and southern Canada. Western limit extends to New Mexico in the south and Saskatchewan in the north. Present in Manitoba, Saskatchewan, and Vermont among other provinces and states.

Seasonality

on from April to October in southern portions of range; June to August in northern portions. or in warmer climates, or with shorter period in cooler regions.

Diet

feed on foliage of Fagus (beech), Quercus (oak), Tilia (basswood/linden), Betula (birch), and Ulmus (elm) . do not feed; they have reduced or non-functional mouthparts typical of many .

Host Associations

Fagus - larval beech
Quercus - larval oak
Tilia - larval basswood, linden
Betula - larval birch
Ulmus - larval elm

Life Cycle

with , larval, pupal, and stages. are gregarious, feeding in clusters on foliage. occurs in soil or leaf litter. Adults emerge to mate and oviposit on host trees. Specific details of egg and pupal stages not documented in available sources.

Behavior

feed gregariously in groups, producing localized areas of heavy within an otherwise intact . This clustering makes them visually conspicuous. High larval result in accumulation of beneath trees.

Ecological Role

As a late-season defoliator, contributes to through leaf consumption and production. Serves as for various and that regulate its . Part of the natural of hardwood forest .

Human Relevance

Occasional pest of trees and ornamental hardwoods due to larval . Damage is primarily aesthetic; single defoliation events do not cause significant tree mortality. Management rarely necessary unless consecutive years of heavy defoliation occur or high-value trees are affected. Mechanical removal of larval clusters or targeted are options if intervention required.

Similar Taxa

Lochmaeus manteoCongeneric , also a late-season defoliator of hardwoods with similar biology and appearance; distinguished by specific pattern and larval characteristics
Anisota senatoriaAnother late-season defoliator with gregarious ; distinguished by orange stripes on and different pattern
Dryocampa rubicundaLate-season with similar ; distinguished by pink and coloration and different larval preferences

More Details

Defoliation Impact

As a late-season defoliator, damage occurs after trees have completed most of their growth and . Consequently, even heavy typically has minimal impact on tree health compared to early-season defoliators. Trees usually refoliate the following spring without long-term consequences.

Research Context

The was included in a 2023 review of late-season hardwood defoliators in the Journal of , which emphasized that typically regulate and management is seldom necessary.