What Is This Moth?

Moth in Sedge Marsh
A moth in the sedge marsh but that is not its home as I eventually learned.


I saw this moth several years ago on March 30, 2006. The temperatures were still around freezing that day and the upland fields were clear of snow, but in the lowlands and in the woods there was still snow on the ground. And now the sedge marsh where this little moth had apparently spent the winter was beginning to flood.


Flooded marsh (on April 02, 2006) where I found the scarce infant moth.
Flooded marsh (on April 02, 2006) where I found the scarce infant moth.


For many years the photograph of the moth remained as “moth in sedge marsh”. Recently, I began working on figuring it out again. When looking for a photo or description of this charcoal-gray moth with fringed wings and a hairy head I ran into many dead ends. One of the problems was I thought this moth was a marsh-dweller whose larvae probably feed on sedge. Another is the general dislike for moths especially drably colored ones which, in the minds of some at least, automatically makes them “pests”. It is bothersome that search engine results for “moth” even with very specific descriptors like “black moth that overwinters as an adult” or some similar combination of words often result in links about pest species (I wonder how they would regard us) and how to get rid of them.

Eventually I found a website with thousands of photographs of moths ranging from the showy luna moth to the obscure moths such as the Micropterigoidea and the moss-eating crambids. After looking over hundreds of photographs of small gray and black moths I found one that looked very similar to the moth I’d seen in 2006. It was Leucobrephos brephoides, the scarce infant moth. Additional literature searches (Beadle and Leckie 2012, University of Alberta Museum) confirmed the identity of the species.

The small infant moth (Leucobrephos brephoides, Family Geometirdae, Subfamily Archiearinae) is a small insect with a wingspan measuring 30 mm. The forewings are black with gray patches and zones. About one-forth from the tip of the forewings is a prominent wavy white band that goes from edge to edge. The hindwings are white bordered in black. The wing tips are fringed with dark hair-like scales. The body is also hairy and the hairs around the head may be pinkish-purple. Both sexes are similar in appearance but males have feathery antennae.

In its fully grown stage the larva is cylindrical, green with thin yellow stripes. The color between the segments is yellowish. The spiracles are white and ringed with black. Minute tubercles, each bearing a single hair, are ringed with pale yellow. The head is pale green and glassy.

The pupa is green at first then becomes pale brown, and finally a dark reddish-brown. The thorax is darker, almost black, and wrinkled. The abdominal segments are coarsely pitted becoming minutely pitted in the last quarter. (Beadle and Leckie 2012, University of Alberta Museum)

Order Lepidoptera, Suborder Ditrysia, Superfamily Geometroidea, Family Geometirdae, Subfamily Archiearinae, Genus Leucobrephos, Species Leucobrephos brephoides (Walker, 1857)

Range and Habitat
The small infant moth occurs from Yukon, British Columbia and Alberta east to Labrador, south to New York, Michigan, Wisconsin, and Minnesota in open mixed tree species forests in the boreal and montane regions (Gibbson and Criddle 1916, McGuffin 1988, Beadle and Leckie 2012, University of Alberta Museum).

Life Cycle
Small infant moths emerge from their cocoons in early spring form March to May. They are the first moths to appear and very often there is still snow on the ground. A single female can lay as many as 135 eggs but the eggs are laid two or three at a time on a leaf scar before leaves emerge on the larval host plants. Preferred host plants are aspen (Populus tremuloides), paper birch (Betula papyrifera), and alders (Alnus spp.) and sometimes balsam poplar (P. balsamifera) and willows (Salix spp.). These tree and shrub species produce catkins before leafing out in the spring so the flowers may be the initial food of the larvae. Eggs hatch in about five to ten days. The larva is a looper or inch-worm.

After feeding and going through five instar stages the larva is ready to pupate about 60 days after hatching. The larva leaves the host plant and burrows into the ground or duff where it pupates until spring. The adult does not overwinter. (Gibbson and Criddle 1916, McGuffin 1988)

Other Species of Leucobrephos
Two other species of Leucobrephos are known but neither is from North America. They are Leucobrephos mongolicum and L. middendorfii (including L. middendorfii ssp. nivea and L. middendorfii ssp. ussuriensis) and live in eastern Siberia and Mongolia (Vojnits 1977) with L. middendorfii extending as far west as the Ural Mountains (Nupponen and Fibiger 2011).

Finding the Moth
I have not seen the small infant moth since but then I haven’t been looking for it either. Now that March has come and gone and we are well into April with warmer weather in the forecast I am going to be on the lookout for it. I will also be checking leaf scars on the twigs and branches of its larval host plants for eggs later in the month and in May. I’d like to get photos of these and the larva. This obscure moth has become very interesting to me.


Beadle, D. and Leckie, S. (2012). Peterson Field Guide to Moths of Eastern North America. Houghton Milfin Harcourt Publishing Company. New York, New York.

Gibbson, A. and Criddle, N. (1916). The Life-History of Leucobrephos brephoides Walk. (Lepidoptera). The Canadian Entomologist. Vol. 4: 133-138.

Lepidoptera.pro website

McGuffin, W.C. 1988. Guide to the Geometridae of Canada (Lepidoptera). III, IV, and V. Subfamilies Archiearinae, Oenochrominae, and Geometrinae. Memoirs of the Entomological Society of Canada No. 145. 56 pages

Moth Photographers Group website

University of Alberta Museum website

Vojnits, A. M. (1977). Archieariinae, Rhodometrinae, Geometrinae II, Sterrhinae II and Ennominae III (Lepidoptera, Geometridae) from Mongolia. Annales Historico-Naturales Musei nationalis Hungarici. Vol. 69: 165-175.

Nupponen, K. and Fibiger, M. (2011) Additions to the checklist of Bombycoidea and Noctuoidea of the Volgo-Ural region. Part II. (Lepidoptera: Lasiocampidae, Erebidae, Nolidae, Noctuidae). Nota Lepidopterologica. 35 (1): 33-50.

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