Other Common Names
Cténuche de Virginie - En français.… Ilze V-G.
Explanation of Names
VIRGINICA: the type specimen was collected in Nova Scotia and named Ctenucha latreillana by Kirby in 1837, but an earlier specimen named Sphinx virginica by Charpentier in 1830 may have been collected in Virginia (?)
Identification
Adult: Large, northern (despite the name) wasp moth. Body metallic blue, including some on thorax. Male (?), has incredible antennae. Compare
Yellow-collared Scape Moth--
Cisseps fulvicollis, which is very similar. Cisseps is smaller, with no blue on thorax. Hindwing (not usually visible) of Ctenucha is black, translucent in Cisseps. Cisseps species is widespread, and its range includes the southeastern United States, where Ctenucha is absent. (Milne
(1) states the simiar Brown Ctenucha, C. brunnea, is found in the southeast. This is a typographic error--that species appears to be found in the south
west.)
Hannah Nendick-Mason summarizes identification of these moths thus:
It seems to me the shape of the yellow "collar" is a good distinction. In Ctenucha it is narrower at the nape and then spreads down to the shoulders (excuse ignorance of a better technical term). In Cisseps it goes almost straight across forming a neat line, and in Harrisina the line is blurred.
Larva: body surface black but covered with tufts of cream-colored or black hairs (or a mix of both) that may obscure ground color; white lateral line and white or yellow subdorsal line may be visible or obscured by hair; thoracic legs black, prolegs red or pinkish; head reddish-brown on top and sides, black on front
Range
Labrador and Newfoundland to Virginia, west to Utah, north to British Columbia (has expanded westward greatly since 1950, and now occurs in every Canadian province)
Covell only mentions eastern distribution: Labrador south to Pennsylvania, west to Manitoba, Kansas.
(2)Habitat
Fields with flowers; day-flying and night-flying; adults are attracted to light
Season
adults fly May-July; two broods
larvae usually seen April to September but may be found any time of year (they overwinter)
Food
Larvae feed on monocots: grasses, sedges, iris.
Adults take nectar at various flowers, such as goldenrod.
Life Cycle
two generations per year; overwinters as a larva beneath leaf litter/matted grasses
Life cycle images:
1.eggs 2.newly hatched larvae 3.dark larva 4.light larvae 5.cocoon 6.mating pair, male and female
Life cycle series by Marcie O'Connor
Remarks
Despite its name, this species is more commonly found in the northern United States and southern Canada than in Virginia, which represents the southern boundary of its range.
The larva's hair color may vary according to season for thermoregulation purposes, from black in the early spring (to absorb solar radiation) to yellowish in summer (to reflect the sun's rays) [
article citation, Paul Fields, Agriculture Canada]
Print References
Covell, p. 75, plate 12 #1
(2)
Himmelman, p. 188, plate C-3, compares
Ctenucha and
Cisseps in life
(3)
Milne, p. 792, fig. 544
(1)
