Moths of North Carolina
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View PDFNotodontidae Members: 11 NC Records

Heterocampa varia Walker, 1855 - No Common Name


Taxonomy
Superfamily: Noctuoidea Family: NotodontidaeSubfamily: HeterocampinaeP3 Number: 930074.00 MONA Number: 7982.00
Comments: One of 21 species in this genus that occur in North America north of Mexico (Lafontaine and Schmidt, 2010), seven of which have been recorded in North Carolina.
Identification
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONATechnical Description, Adults: Forbes (1948); Schweitzer et al. (2011)Technical Description, Immature Stages: Forbes (1948); Wagner (2005); Schweitzer et al. (2011)                                                                                 
Adult Markings: A moderately large Prominent. The ground color of the forewings is ashy gray with a bluish cast when fresh (Forbes, 1948). The basal, antemedian, and postmedian lines are black, double, and filled with a slight yellowish shade. More conspicuous is a whitish shade that extends from the apex to the cell and a series of black dashes bordering it on the outward side, forming the upper part of the subterminal line. A separate pale spot is also located in cell M3. Males in general are very similar in size, color, and forewing pattern to the much more common H. obliqua. Forbes mentions that the pale spot in M3 has more of a bar shape in varia and a more of a circular shape in obliqua, but that difference is not apparent in our specimens. More reliable differences given by Forbes are seen in the hindwings: they are nearly pure white in varia, with only a dark anal spot and dark bars in the fringe, whereas in obliqua, there is usually a dark shade in the fold and a well-defined terminal line (Forbes, 1948). The basal area of the forewing and thorax may also be paler gray in varia than in obliqua and varia lacks the greenish tint found in some specimens of obliqua. In most cases, these external differences are only slight and inspection of the the 8th sternite offers the surest way of distinguishing the males of the two species (see Structural Features below). Females are usually more separable (Schweitzer et al., 2011): in varia, they have a coloration similar to the males whereas in obliqua, females usually have a strong brown shade located between the discal spot and pale apical shade. Forbes, however, points out that there at least some forms of female obliqua that are similar to males and, by extension, similar to varia. Where this is true, the much darker hindwings found in female obliqua may distinguish them from varia, whose hindwings usually are fuscuous only in the subterminal area and paler whitish towards the base.
Wingspan: 45-50 mm, males; 50-57 mm females (Forbes, 1948)
Adult Structural Features: Antennae of males are pectinate basally and simple at the apex; antennae of females are simple over their entire length. Males of varia differ from those of obliqua in both the genitalia and in the configuration of the 8th sternite, which can be easily seen by brushing away the scales on the underside of the tip of the abdomen: in obliqua, there is a conspicuous curved, indented line that connects the two sternal pits; in varia, no such indentation exists and the posterior edge of the sternite has two lateral lobes that are much better developed than in obliqua. The internal genitalic features also easily distinguish males of the two species, with pronounced differences in both the socii and aedeagus (see Forbes, 1948, for a description and illustrations).
Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].
Immatures and Development: Larvae are similar to those of Heterocampa obliqua. Early instars have thoracic "antlers" that are shed as they mature. Later instars have a smooth, pale green body with a pale dorsal stripe. Wagner (2005) describes varia as having the dorsal stripe much less constricted between two white saddles than in obliqua, with the constriction being about half as wide as the posterior saddle. A white triangle at the anterior of the body also extends forward across the top of the head in varia, reaching the antennae (a larva of varia is illustrated in Schweitzer et al., 2011).
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Our records come primarily from the Fall-line Sandhills; the historic records from other parts of the state need to be confirmed
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: Possibly bivoltine, with flights in May and June and again in July and August
Habitats and Life History
Habitats: Habitats in the Fall-line Sandhills all consist of Pine--Scrub Oak Sandhills, where a variety of xerophytic oaks occur, including Blackjack and Post Oaks. While Turkey Oak is common at these sites, we do not have records for varia from Xeric Sandhill Scrub habitats where Turkey Oak is nearly the only hardwood tree species present. Habitats represented by the historic Piedmont localities are unknown, but likely possessed Blackjack or Post Oaks.
Larval Host Plants: Heterocampa varia is believed to feed solely on Oaks (Forbes, 1948; Wagner, 2005; Schweitzer et al., 2011), and probably only on xerophytic species, with larvae having been found on Post Oak (Quercus stellata), Dwarf Chiquapin Oak (Q. prinoides), and Bear Oak (Q. ilicifolia) in the Northeast, with Blackjack Oak (Q. marilandica) and Turkey Oak (Q. laevis) also considered likely (Schweitzer et al., 2011).
Observation Methods: Adults come at least to some extent to blacklights, with females coming about two hours after dusk and males mostly after 1:00 a.m. (Schweitzer et al., 2011). Adults probably do not feed and are unlikely to be found at bait or flowers.
Wikipedia
See also Habitat Account for Xeric-Mesic, Sandy Woodlands and Scrub
Status in North Carolina
Natural Heritage Program Status: SR
Natural Heritage Program Ranks: G3G4 S1S2
State Protection: Listed as Significantly Rare by the Natural Heritage Program. That designation, however, does not confer any legal protection, although permits are required to collect it on state parks and other public lands.
Comments: This species has long been considered rare over most of its range (Forbes, 1948), the one exception being the New Jersey Pine Barrens, where it is considered uncommon (Schweitzer et al., 2011). We have very few records for this species in North Carolina, where it is vastly outnumbered by Heterocampa obliqua even within the dry-xeric oak woodlands that varia prefers (we routinely check the sternal plates of all specimens in this group, having inspected hundreds of H. obliqua for every H. varia we have found). While occurring fairly regularly, if sparsely, at certain sites, varia appears to be absent from many other areas where it might be expected to occur, particularly dry oak-hickory woodlands that we have sampled in the Piedmont where Blackjack and Post Oak are both common species. Outside of the Sandhills, however, those habitats tend to occur in relatively restricted locations and it may be no accident that the best populations of this species occur at Fort Bragg and vicinity where dry oak woodlands are still extensive and unfragmented.

 Photo Gallery for Heterocampa varia - No common name

Photos: 3

Recorded by: SPH on 2003-05-28
Richmond Co.
Comment: Male. Confirmed by checking 8th sternite. Wingspan = 4.7 mm; forewing length = 2.1 mm.
Recorded by: SPH, SH, CH on 2000-08-25
Moore Co.
Comment: Female. Wingspan = 5.7 mm; forewing length = 27. mm.
Recorded by: Steve Hall, Scott Hartley, Chris Helms on 2000-06-24
Moore Co.
Comment: Male; confirmed by checking 8th sternite. Wingspan = 5.0 mm; forewing length = 2.8 mm.