New York Natural Heritage Program
Inland Barrens Buckmoth
Hemileuca maia maia (Drury, 1773)

General Description [-]
This is the widespread oak feeding buckmoth of the eastern United States that is found mostly from southern New Jersey to Missouri and southward, but has isolated colonies inland north well into New York and at least formerly Maine.

Identifying Characteristics [-]
The subspecies taxonomy suggested by NatureServe is followed here. Populations on Long Island and coastal southeastern New England are considered a separate subspecies. For New York, this means Hemileuca maia maia refers only to the more normal mainland populations, which are known from Glens Falls and Albany southward to the Shawangunk Ridge in Orange County. Maculation (spotting) of larvae and almost all adults, and morphological characters of these mainland New York populations, appear to fall within the variation of the more variable southern populations which NatureServe and most literature consider typical H. maia maia, although New York and other far northern populations do differ in their close association with scrub oak. The Albany area population has probably been isolated for a long time and has, or had, a very rare form in which the white forewing band is completely missing. Apparently, such a form is not known from any other eastern United States population of any species of this genus. Tuskes et al. (1996) illustrate a Long Island adult, as well as more normal adults. Wetland buckmoths are not considered part of this species.

Characters Most Useful for Identification [-]
Adult buckmoths are unmistakable as a group and nearly always can be identified to species by habitat, which would be scrub oak barrens for this species, and to subspecies by range, which in New York means any place other than Long Island. Young larvae are found in clusters on scrub oak in May and are black and spiny. They could be confused with Mourning Cloak larvae, but these are usually on willows or elms. Older larvae differ from other species and also from populations on Long Island in not having extensive yellow dorsally or a yellow lateral line. The last instars are described as plain blackish with no real pattern, but sparsely sprinkled with pale flecks. Populations south of New York are more variable and those in the southeastern region of New York could be variable as well.

Behavior [-]
This buckmoth is found among scrub oaks or on dry ridgetops with scrub oak or possibly other shrubby oaks. It does not occur in wetlands although an individual could stray into a wetland.

Diet [-]
The eggs are laid on scrub or dwarf chestnut oak and the larvae predominately feed on these species. Later instars (stages) wander to other foodplants such as cherry and willow.
Inland Barrens Buckmoth Images
click to enlarge
The Best Time to See
The adult flight season is brief, probably no more than two weeks in a given year. In the Albany Pine Bush, the flight season starts on a sunny day soon after about September 25 and usually peaks the first week of October. The flight period should run a few days later south of there, and perhaps a few days earlier at Glens Falls. The eggs probably hatch before May 15 in warm springs, but May 20 is generally about average. They hatch while the scrub oak foliage is expanding and larvae must reach fourth instar before this foliage hardens. After the fourth instar, the growth slows and the last instar can take up to a month. Female larvae feed about a week longer than males. Pupation starts about mid-July and most are in the soil by the end of the month. While most pupae diapause (a period where growth is suspended; i.e, a dormant period) only a few weeks and eclose (emerge as an adult from the pupal case) the same autumn, probably about 10-30% overwinter and eclose in the second autumn. In states farther south, a few pupae overwinter two or three times and this might also happen in New York. A viable population will always have pupae in the soil. In contrast to southern populations, the Albany area adults are active only in sunny, hazy, or partly cloudy weather. They may abruptly cease flying if a large cloud obscures the sun, especially on a cool day. Males fly mostly between 10:00 am and 2:00 pm, and mating occurs during this time. Most females mate a few hours after eclosion. Mated females rest briefly and then take flight that afternoon when they locate a suitable oak and lay an egg ring. If it is sunny, the female usually flies a second time and she lays another egg ring if a suitable oak is found quickly enough. However, many females manage to lay only one egg ring the first day and the second egg ring is then laid on the next sunny day when oviposition is sometimes preceded by a second mating. Early instar larvae also feed mostly in sunny weather. Older larvae are less fussy, but still feed mostly in the daytime and are lethargic in cool weather.
Reproducing Larvae present and active Eggs present outside adult Pupae or prepupae present
The time of year you would expect to find Inland Barrens Buckmoth reproducing (red shading), larvae present and active (blue shading), eggs present outside adult (green shading) and pupae or prepupae present (orange shading) in New York.
Similar Species
  • Bogbean Buckmoth (Hemileuca sp 1)
    A colony of buckmoths in a wetland will be another species, not Hemileuca maia maia, and should be reported to the Natural Heritage Program along with photos of the larvae or an adult specimen, since adult photos are usually not useful beyond verifying genus.