Moths of North Carolina

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View PDF	Psychidae Members:	Dahlica Members:	28 NC Records

Dahlica walshella (Clemens, 1862) - No Common Name

Taxonomy

Superfamily:
Tineoidea

Family:
Psychidae

Subfamily:
Naryciinae

P3 Number:
300007

MONA Number:
435.00

MONA Synonym:
Siederia walshella

Comments: The family Psychidae contains as many as 1,350 species that are found worldwide. The females of many species are flightless, and the larvae of all species live in constructed cases or bags, hence the name bagworms. Siederia is a small genus with eight currently recognized species and only one North America representative.

Identification

Field Guide Descriptions:

Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLD

Technical Description, Adults: Davis (1964)

Technical Description, Immature Stages: Davis (1964)

Adult Markings: The following is based in part on descriptions by Clemens (1862), Forbes (1923), and Davis (1964). The head and head tufts of the males are dark gray, and the antenna is dark gray to fuscous with slight whitish spotting. The scales of the vertex usually have whitish tips. The forewing is mottled with a patchwork of alternating light and dark marks. These are typically small, pale gray patches that alternate with dark gray to fuscous patches. There are no other defining marks, except for a better organized series of similar alternating light and dark marks that extend along the costa, around the termen, and along the inner margin. Those in the apical third of the costa and along the termen tend to be larger and more conspicuous. The cilia on the forewing are gray and increase in length from the apex to the anal angle. The hindwing and cilia are gray. The forewing is oblong and gently bowed along the termen, and the resting males hold the wings tent-like and resemble a caddisfly. The females are wingless and live in silken cases. The antenna of the female is long with 20-24 segments. The middle tibia has either one or two apical spurs, and the hindtibia has an apical pair of spurs (Davis, 1964).

Wingspan: 12-14 mm for males (Davis, 1964)

Forewing Length: 6-7 mm TL for females (Davis, 1964)

Adult Structural Features: Davis (1964) has descriptions and illustrations of the male and female genitalia.

Adult ID Requirements: Identifiable from good quality photos of unworn specimens.

Immatures and Development: The larvae live in silken cases that are 7-10 mm long and 1.5-2 mm wide. The cases are fusiform in outline and have a somewhat leathery consistency. The silk is grayish and often covered with tiny sand grains, fragments of lichens, larval excrement, and various small animal remains (Davis, 1964). The larvae feed on lichens (Chambers, 1873) and appear to disperse from their feeding sites before pupating within the case. In Illinois, they commonly end up in large numbers on the sides of houses (BugGuide). The adults emerge within a week or so after the larva pupate (Chambers, 1873). The adults emerge very early in the year in North Carolina, which suggests that this species overwinters either as larvae or pupae.

Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.

Distribution in North Carolina

Distribution: Dahlica walshella is found in eastern North America where the range extends from extreme southern Canada and the New England states southward to South Carolina and Mississippi, and westward to Illinois, Michigan and Minnesota. As of 2020, we have only three site records from the Piedmont and lower mountains.

County Map: Clicking on a county returns the records for the species in that county.


Flight Dates: High Mountains (HM) ≥ 4,000 ft. Low Mountains (LM) < 4,000 ft. Piedmont (Pd) Coastal Plain (CP) Click on graph to enlarge
Flight Comments: Adults have been observed from February through November in different areas of the range, with peak number occurring in March and April in most regions. As of 2020, our records are from early February through late March. Populations in North Carolina are univoltine.

Habitats and Life History

Habitats: The specific habitats are poorly documented, but the larvae appear to feed rather heavily on lichens, particularly those that grow on conifers.

Larval Host Plants: The larvae appear to be specialize on lichens, particularly those that grow on pines and hemlocks (Forbes, 1923; Robinson et al., 2010). - View

Observation Methods: The adults are attracted to lights during the late winter-early spring warm-up. The pre-pupal larvae can sometimes be found on the sides of houses or other structures.

Wikipedia

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: GNR SU

State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.

Comments: We currently do not have sufficient information on the distribution and abundance of this species to assess its conservation status.

Photo Gallery for Dahlica walshella - None

Photos: 16

	Recorded by: Jim Petranka on 2025-10-06 Madison Co. Comment: Case with larva was attached to the side of a garage; was gone the next morning. Adults have been collected in the spring from < 30' from where the case was found.		Recorded by: John Petranka on 2024-02-10 Orange Co. Comment:
	Recorded by: Jim Petranka on 2023-03-24 Madison Co. Comment:		Recorded by: Jim Petranka on 2022-04-11 Madison Co. Comment:
	Recorded by: tom ward on 2022-03-21 Buncombe Co. Comment:		Recorded by: tom ward on 2022-03-16 Buncombe Co. Comment:
	Recorded by: tom ward on 2022-03-11 Buncombe Co. Comment:		Recorded by: tom ward on 2022-03-11 Buncombe Co. Comment:
	Recorded by: tom ward on 2022-03-05 Buncombe Co. Comment:		Recorded by: tom ward on 2022-03-05 Buncombe Co. Comment:
	Recorded by: Brian Bockhahn on 2022-03-04 Buncombe Co. Comment:		Recorded by: tom ward on 2022-03-04 Buncombe Co. Comment:
	Recorded by: Ken Kneidel on 2022-02-19 Yancey Co. Comment:		Recorded by: Brian Bockhahn on 2022-02-12 Buncombe Co. Comment:
	Recorded by: Stephen Hall on 2021-03-12 Orange Co. Comment:		Recorded by: Steve Hall on 2015-03-11 Orange Co. Comment: