Moths of North Carolina
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Hemipachnobia Members:
2 NC Records

Hemipachnobia monochromatea (Morrison, 1874) - Sundew Cutworm Moth


Taxonomy
Superfamily: Noctuoidea Family: NoctuidaeSubfamily: NoctuinaeTribe: NoctuiniP3 Number: 933546.00 MONA Number: 10993.10
Comments: Hemipachnobia is a North American genus composed of two species, both of which have been recorded in eastern North Carolina. The genus Hemipachnobia was defined by McDunnough in 1929, with H. monochromatea designated as the type species (McDunnough, 1929; Lafontaine, 1998). Although Smith (1891) tentatively listed subporphyrea as a synonym of monochromatea, other authors treated the two species as belonging to separate genera until relatively recently (Hall and Sullivan, 2000).
Identification
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIFTechnical Description, Adults: Forbes (1954, as Cerastis monochromatea); Lafontaine (1998)Technical Description, Immature Stages: Hooker (1919, as Epipsilia monochromatea); Forbes (1954, as Cerastis monochromatea); Lafontaine (1998); Wagner et al. (2011)                                                                                 
Adult Markings: A medium-sized Noctuine. The ground color is typically reddish-brown, occasionally with a tawny tint (Forbes, 1954; Lafontaine, 1998), as in our two specimens, although there is a a form in New Jersey that has a purplish color similar to specimens of subporphrea (D.F. Schweitzer, pers. comm.). The only conspicuous markings are the darker brown antemedian and postmedian lines; the antemedian is slightly excurved and the postmedian is somewhat dentate and outwardly bent at the end of the cell. A diffuse whitish subterminal line may be present in some specimens, separating the otherwise concolorous median and basal areas of the forewings from a paler subterminal band. The orbicular, reniform, and claviform spots are all obsolete, distinguishing Hemipachnobia species from those of Cerastis (Forbes, 1954). Monochromatea is similar but smaller than subpoprhyrea (Lafontaine, 1998). Although Lafontaine also stated that the postmedian is less serrated in monochromatea than in subporphyrea and the subterminal area usually more concolorous, these characters, as well as wing color and other features of the markings appear to overlap in at least some specimens of these two species. For that reason, as well as the conservation significance of records for either of these two species, we recommend that identities be established based on dissection of the males.
Wingspan: 30-35 mm (Forbes, 1954)
Adult Structural Features: The differences separating males of subporphyrea and monochromatea were discovered by Timothy McCabe and Dale Schweitzer (Schweitzer, 1996) and were formally described and illustrated by Lafontaine (1998). The valve in male subporphyrea has three prominent distal projections, while the valve in monochromatea has only a single distal projection. The juxta of subporphyrea has a triangular, wedge shaped posterior projection, while the juxta of monochromatea, possesses a narrowly conical posterior projection. According to Lafontaine (1998), key differences also separate the females of subporphyrea and monochromatea, with the ductus bursae heavily sclerotized and anteriorly enlarged in subporphyrea and lightly sclerotized and anteriorly tapered in monochromatea.
Structural photos
Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].
Immatures and Development: Hooker (1919) described early instars as pale in color, changing first to green and then ultimately to brown as they aged. Mature larvae are reddish to purplish brown and possesses a conspicuous, white mid-dorsal line but no other strong markings. In all of these respects, they are very similar to the larvae of subporphyrea, as described by Hall and Sullivan (2002); see Wagner et al. (2011) for a detailed description and illustrations. According to T. McCabe (pers. comm.), larva of monochromatea enter a diapause in the second instar, unlike subporphyrea in which no diapause has been observed (Hall and Sullivan, 2002). Overwintering is done by mature larvae.
Larvae ID Requirements: Identifiable only through rearing to adulthood.
Distribution in North Carolina
Distribution: Appears to be restricted to the Albemarle-Pamilico Peninsula in the northern part of the Coastal Plain.
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: Our two records for this species come from early to mid-May, just beyond the latest records we have for H. subporphyrea. This difference, however, may be due to the more northerly location (and probably cooler microclimate) of the location where monochromatea was collected in the state.
Habitats and Life History
Habitats: Both of our records come from an extensive area of peatlands. One record was from a High Pocosin and the other from a Pond Pine Woodland. Both of these areas are located close to a large area of Low Pocosin that contains one of the largest concentrations in North Carolina of Cranberries and Sundews occurring in close association.
Larval Host Plants: Hooker (1919) described early instar larvae as feeding on the undersides of the leaves of Sundews (Drosera sp.), but later switching to feeding on Cranberry (Vaccinium macrocarpon). Timothy McCabe (pers. comm.) has also observed larvae feeding initially on Sundews but subsequently feeding on other species of Vaccinium. Wagner et al. (2011) also mention use of Sheep Laurel (Kalmia angustifolia) as another heath used in later instars.
Observation Methods: Comes well to blacklights but we are not aware of records from bait or from flowers.
Wikipedia
See also Habitat Account for Coastal Plain Herbaceous Peatlands
Status in North Carolina
Natural Heritage Program Status: SR
Natural Heritage Program Ranks: G4 S1?
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: The sole North Carolina occurrence of this species appears to be disjunct from the rest of its range; the next nearest known populations occur in New Jersey (Lafontaine, 1998). This species may also be an extreme habitat specialist, occurring in open peatland habitats that contain both Sundews and Cranberries (or other heaths). The sole North Carolina occurrence of this species is located at a site that is highly vulnerable to the effects of sea-level rise, including the destructive effects on peatlands due to salt-water intrusion. This species, thus, appears to be one of the most endangered species in the state.

 Photo Gallery for Hemipachnobia monochromatea - Sundew Cutworm Moth

Photos: 2

Recorded by: SPH on 1994-05-11
Dare Co.
Comment: Female. Wingspan = 3.9 cm; forewing length = 1.6 cm.
Recorded by: SPH on 1994-05-10
Dare Co.
Comment: Male. Wingspan = 3.8 cm; forewing length = 1.7 cm. Identity confirmed by dissection.