Synonyms and other taxonomic changes
This is an enigmatic, problematic genus of small moths. The first species were originally described as Geometrids based on wing venation (Walker 1861, Hulst 1896, Dyar 1902). Later they were recognized as "Noctuids" (in the larger concept of Noctuoidea), although somewhat aberrant even in that placement (Barnes and McDunnough 1913, Dyar 1913). The genus has most recently been placed in the Erebidae, provisionally in the Scolecocampinae (Lafontaine and Schmidt 2010)(1)
Small moths (wingspan 15 mm or less) that resemble miniature Geometrids, most often perching with wings spread widely. Most species have small dark spots scattered on the gray or tan wings, but two species (brauneata and "n. sp. 6") have a blotchy brown pattern and others such as penumbrata may lack most of the spotting.
Lafontaine and Schmidt (2010)(1)
list four species of Sigela
for North America:
-- Sigela brauneata (Swett, 1913)
-- Sigela penumbrata Hulst, 1896
-- Sigela basipunctaria (Walker, 1861)
-- Sigela eoides (Barnes & McDunnough, 1913)
and recent work by Kons & Borth (2012)
and Kons et al. (2017)
suggests that as many as five additional unnamed species are present in North America.
Troubridge (2020) (2)
described several of these previously undescribed species.
Barnes, W., and J. H. McDunnough. 1913. Contr. Nat. Hist. of Lepidoptera of North America, Vol. 2, pt. 4. The Review Press, Decatur, IL. [Describe Acidaliodes eoides on p. 166, pl. 3, fig. 1]
Dyar, H. 1902. A list of North American Lepidoptera and key to the literature of this order of insects. Bull. U. S. Nat. Mus. 52. [Eois and Sigela on pp. 295-298]
Dyar, H. 1913. Notice of Volume II, No. 4, of Barnes and McDunnough's "Contributions to the Nstural History of the Lepidoptera of North America". Insecutor Inscitiae Menstruus 1(8):102-106. [Places basipunctaria and penumbrata both in Sigela]
Hulst, G. D. 1896. A classification of the Geometrina of North America, with descriptions of new genera and species. Trans. Amer. Ent. Soc. 23(3):245-386. [Description of Sigela n. gen. on p. 307; of S. penumbrata n. sp. on p. 307]
Kons, H. L., Jr., R. J. Borth, J. T. Vargo, L. A. Durden, and J. R. Slotten. 2017. A Lepidoptera biodiversity blitz at the Nature Conservancy's Splinter Hill Bog Preserve in Baldwin County, Alabama. S. Lep. News 39(2):93-143.
Lafontaine, J. D., and B. C. Schmidt. 2010. Annotated check list of the Noctuoidea (Insecta, Lepidoptera) of North America north of Mexico. ZooKeys 40:1-239.
Walker, F. 1861. List of the Specimens of Lepidopterous Insects in the Collection of the British Museum, part XXII--Geometrites. London. [Original description of Acidalia basipunctaria on p. 785]