Moths of North Carolina
Scientific Name:
Common Name:
 Family (Alpha):
« »
View PDFNoctuidae Members:
Exyra Members:
45 NC Records

Exyra ridingsii (Riley, 1874) - No Common Name

Taxonomy
Superfamily: Noctuoidea Family: NoctuidaeSubfamily: PlusiinaeTribe: PlusiiniP3 Number: 931190.00 MONA Number: 9023.00
Comments: One of three members of this genus, all of which are highly associated with the solely eastern North American genus of Pitcher Plants, Sarracenia. All three have been recorded in North Carolina.
Identification
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Jones (1921); Forbes (1954); Lafontaine and Poole (1991)Technical Description, Immature Stages: Jones (1921); Forbes (1954); Lafontaine and Poole (1991); Wagner et al. (2011)                                                                                 
Adult Markings: A medium-small, black-and-yellow striped Noctuid. The head and front half of the thorax are dark, blackish brown, differing from the crimson-and-yellow found in Exyra fax but very similar to the pattern shown by E. semicrocea. Unlike semicrocea, a strong, black antemedian line is usually present, strongly contrasting with the yellow ground color of the the basal and medial areas of the wing (sometimes extending beyond the postmedian). Similarly dark median and postmedian lines are often present, as well as a wider dark subterminal shade. Sometimes the bands are fused from the median outward to form a solid black outer portion of the wing. In these dark forms, the inner edge of the black portion is more curved or irregular than in semicrocea.
Adult Structural Features: Male and female genitalia are illustrated in Lafontaine and Poole (1991).
Adult ID Requirements: Identifiable from good quality photos of unworn specimens.
Immatures and Development: Mature larvae are wine red with white, intersegmental bands. Unlike Exyra fax but similar to E. semicrocea, elongated lappets (pinnacula or warts) occur on the thorax and anterior portion of the abdomen, that apparently help the larvae from getting stuck in the narrow bottom reaches of the pitcher plant tubes (Jones, 1921). In E. ridingsii, the lateral (= subdorsal) lappets on the thorax are longer than in semicrocea, approaching the lengths of those on the abdomen and longer than the dorsal warts on the same thoracic segments (Lafontaine and Poole, 1991; Wagner et al., 2011). The life history of the Exyra species was well-described by Frank Morton Jones, who studied them initially in Richmond County, NC (Jones, 1904). All life stages are closely associated with their host plants: eggs are laid within the entrance to the pitcher; larvae seal off the entrances to the tubes to create a sealed feeding chamber; both overwintering by larvae and pupation typically occurs within the bases of the tubes; and adults typically rest within the tubes between dispersive flights (see Jones, 1921, for details, including slight differences between species).
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Occurs in both the northern and southern Coastal Plain, including the Fall-line Sandhills. Formerly, at least, it was also recorded in several bogs in Montgomery County and in Wake County in the eastern Piedmont. However, it now appears to be extirpated from that region.
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