Moths of North Carolina
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View PDFGelechiidae Members: 8 NC Records

Theisoa constrictella (Zeller, 1873) - No Common Name

Superfamily: Gelechioidea Family: GelechiidaeSubfamily: GelechiinaeTribe: AnomologiniP3 Number: 420635.00 MONA Number: 1722.00
Field Guide Descriptions: Leckie and Beadle (2018)Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONATechnical Description, Adults: Chambers (1874); Forbes (1923)Technical Description, Immature Stages: Heinrich (1920)                                                                                 
Adult Markings: This is a distinctive moth that has the dark basal third of the wing contrasting with a whitish antemedial line. Other distinctive marks include a black discal dot, and a black costal spot at two-thirds that abuts a pale costal spot. The following detailed description is based on those of Chambers (1874, p. 76) and Forbes (1923). The labial palp is dull white to light tan and recurved. The third segment is much longer than the second, and the tip extends nearly to the thorax. The face is white, but becomes more ocherous towards the vertex. The antenna is white to pale with dark brown annulations. The thorax and basal third of the forewing are light wood brown to somewhat darker, and contrast with the lighter two-thirds of the wing. The dark basal third abuts a pale whitish antemedial line that is lined internally with black scales. The line is broadly wavy and turns inward on the costal and dorsal margins. It is followed by a paler saffron yellow shade that fills much of the remainder of the wing, and becomes darker towards the apex. A black discal dot is often evident at about two-thirds the wing length. A blackish costal spot is present at about two-thirds that is followed by a pale spot that sometimes extends obliquely to form a short fascia. The fringe is dusky yellowish. The hindwing and cilia are light yellowish-brown.
Immatures and Development: The larvae feed on the undersides of elms. Each larva constructs a web that is typically made between two lateral veins (Heinrich, 1920). The silk webbing draws the leaf together slightly and the larva feeds on the epidermis within. It also constructed a tube beneath the webbing that is composed of silk and frass that it uses as a shelter when not feeding. Larvae that Heinrich (1920) collected in September in Virginia pupated in October, then overwintered in the pupal stage. The adults emerged the following July. Pupation occurs in a thin, oval, silken cocoon (Forbes, 1923). The mature larva is 6.5-7.0 mm long with a whitish body that has a slight pinkish tinge near the dorsum (Heinrich, 1920). The head is yellowish, the thoracic and anal shields are very pale yellow, and the body tubercles are brown.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Theisoa constrictella is found in eastern North America from New Hampshire, Vermont and adjoining areas of southern Canada (Ontario; Quebec) southward to Florida, and westward to central Texas, Oklahoma, Missouri, and Illinois. Populations appear to be uncommon in the Atlantic Coastal Plain from Virginia south to Georgia. As of 2021, our records are all from the 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: Adults have been observed from March through September in areas outside of North Carolina. Populations appear to be bimodal in southern populations, with the first brood in March through May, and the second in July through September. Populations in North Carolina also appears to be bivoltine, with the first seasonal peak in April and May, and the second in July and August.
Habitats and Life History
Habitats: Theisoa constrictella uses elms as hosts. The exact species are poorly documented other than American Elm, which is found in bottomlands, river floodplains, and on the lower, gentler slopes of sites with rich, circumneutral soils.
Larval Host Plants: American Elm (Ulmus americana) is the only documented host (Robinson et al., 2010), but other elms are likely used.
Observation Methods: The adults are attracted to lights. Host use needs to be better documented, so we encourage naturalists to search for the larvae on elms.
See also Habitat Account for General Wet-Hydric Floodplains
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: This species appears to be relatively secure within the Piedmont, but more information is needed on host use, distribution and abundance before we can accurately assess its conservation status. The historical decline of American Elm may have adversely impacted this species.

 Photo Gallery for Theisoa constrictella - No common name

Photos: 6

Recorded by: Gary Maness on 2020-05-16
Guilford Co.
Recorded by: Gary Maness on 2020-05-16
Guilford Co.
Recorded by: Kyle Kittelberger on 2020-04-24
Wake Co.
Recorded by: T. DeSantis on 2016-05-28
Orange Co.
Recorded by: T. DeSantis on 2014-08-04
Durham Co.
Recorded by: Harry Wilson on 2013-08-13
Wake Co.