Moths of North Carolina
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10 NC Records

Epiblema discretivana (Heinrich, 1921) - Epiblema Species Group

Epiblema discretivana
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Taxonomy
Superfamily: Tortricoidea Family: TortricidaeSubfamily: OlethreutinaeTribe: EucosminiP3 Number: 51a1086.1 MONA Number: 3188.00
Identification
Field Guide Descriptions: Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Heinrich (1921); Wright and Gilligan (2023).Technical Description, Immature Stages: Miller (1976).                                                                                 
Adult Markings: The following description mostly is based on those of Heinrich (1921) and Wright and Gilligan (2023). This is a medium-sized Epiblema with a moderately broad forewing. The antennae, palps, face, and head vary from dull fuscous to ashy fuscous. The thorax is dull fuscous, while the forewing ground color is a dirty grayish white with darker markings. An outwardly angulated basal patch covers the basal third of the wing and varies from dark gray to grayish-fuscous. It is followed by a grayish white medial band that has gray transverse reticulations. Following this is a vaguely defined blackish-gray pretornal mark. The ocellus is grayish-white and has gray lateral bands, while the termen has a dark gray or fuscous band that extends from the tornus to the apex. The hindwing is smoky fuscous and the fringe is grayish white with a dull fuscous band along its base.

Eucosma discretivana most closely resembles E. obfuscana, but the latter has the face, head, thorax, and base of antennae covered with inky blue-black scales. In addition, the dark margin of the termen of E. obfuscana is bluish-black and only extends from the apex to a little over one-half the length of the termen. In E. discretivana there is none of the bluish-black scaling that is so noticeable in E. obfuscana and the entire length of the termen is faintly dark margined. Eucosma discretivana also resembles E. desertana, but the latter has bluish-black scaling that is similar to that of E. obfuscana.
Wingspan: 13-16 mm (Heinrich, 1921).
Forewing Length: 5.8-8.4 mm; mean = 6.9 mm (Wright and Gilligan, 2023).
Adult Structural Features: Wright and Gilligan (2023) provide descriptions and illustrations of the male and female genitalia.
Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].
Immatures and Development: The following life history account is based on that of Miller (1976), who reared adults from three species of Baccharis. The young larvae bore into the stems of the host plants and feed on the internal tissues except for the cambium. Feeding is typically confined to a short length of the stem (2.1-3.3 cm) and triggers the plant to produce an elongated gall. Maximum stem swelling seems to be associated with the point where larvae concentrate their feeding within the stem. The larvae modify the initial entry passages to create debris hatches and plugs in the upper half of the gall to void frass and debris. When mature, each larva excavates an exit tunnel for the adult to emerge in the upper half of the gall, but leaves a thin layer of plant tissue intact. It then spins a silken funnel that guides the emerging insect into the exit tunnel. The exit tunnels are completed before winter, and the larvae overwinter and pupate the following spring.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Epiblema discretivana is found in coastal habitats from southern Texas eastward across the Gulf Coast to Florida, and northward along the Atlantic Coast to Rhode Island (Wright and Gilligan, 2023). As of 2024, all of our records are from the Coastal Plain, with the exception of one larval record from the eastern Piedmont.
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: Wright and Gilligan (2023) reported flight dates that ranged from mid-March to the end of the July, with one record from south Texas dated 3 October. Populations in North Carolina are univoltine. As of 2024, our records range from late-April through late-June.
Habitats and Life History
Habitats: Local populations are commonly found where Groundsel-tree, which is the primary host, grows locally. This species is commonly found around the margins of maritime wetlands, but has rapidly expanded its range westward in North Carolina where it grows in disturbed sites such as damp roadsides, ditches and weedy fields.
Larval Host Plants: Miller (1976) reared adults mostly from Groundsel-tree (Baccharis halimifolia), but also from Saltwater False-willow (B. angustifolia) and Silverling (B. glomeruliflora). In North Carolina, galls have been observed on Groundsel-tree. - View
Observation Methods: The adults are attracted to lights, and the elongated galls can be found on the stems of Baccharis.
Wikipedia
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: GNR[S2S3]
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.
Comments: This species appears to be uncommon in North Carolina, with only five site records as of 2024. More information is needed on its habitat requirements and distribution and abundance before we can accurately assess its conservation status within the state.

 Photo Gallery for Epiblema discretivana - Epiblema Species Group

Photos: 3

Recorded by: Tracy Feldman on 2024-02-29
Wake Co.
Comment: A gall on Baccharis halimifolia. 		Recorded by: Tracy Feldman on 2024-02-29
Wake Co.
Comment: A gall on Baccharis halimifolia.
Recorded by: Tracy Feldman on 2024-02-29
Wake Co.
Comment: A gall on Baccharis halimifolia.