Ennomos subsignaria

University of Alberta E.H. Strickland Entomological Museum Read more about this collection »

Common NameElm Spanworm SeasonalityThe only Alberta record is for late May; July and August elsewhere (McGuffin 1987). IdentificationA large pale white-tan geometrid with pointed projections along the wing margins. The wings lack conspicuous markings. Tetracis cachexiata is similar, but has a straight transverse line crossing the forewing.

Scientific Name Ennomos subsignaria Common Name Elm Spanworm Habitat In Alberta, restricted to southern prairie riparian woodlands. Seasonality The only Alberta record is for late May; July and August elsewhere (McGuffin 1987). Identification A large pale white-tan geometrid with pointed projections along the wing margins. The wings lack conspicuous markings. Tetracis cachexiata is similar, but has a straight transverse line crossing the forewing. Life History

The larva occurs in several colour forms, all of which resemble twigs like most ennomine geometrids. Colour forms include yellow, green, brown, and nearly black (Wagner et al. 2001). McGuffin (1987) states that some colour forms may be induced by population density, with crowded larvae being dark and isolated larvae light. Eggs are laid on the undersides of twigs, where they overwinter. Like E. magnaria, larvae often spin a cocoon amongst foliage to pupate, unlike most other geometrids which pupate underground. In the East this species is sometimes abundant enough to defoliate trees (Wagner et al. 2001).

Conservation Rare in AB (1 record), but widespread and occasionally reaching pest status elsewhere. Diet Info Larvae feed on a variety of hardwood trees; the only recorded hosts which occur in Alberta include white birch, trembling aspen (Populus tremuloides) and Manitoba maple (Acer negundo) (Prentice 1963). Range Southeastern Alberta east to Nova Scotia, south to FL and TX (McGuffin1987).

Page Citation

"Species Details - Ennomos subsignaria, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-4194/9-51527. Accessed 21 Dec. 2024.

References

9 results plotted on map in 3 markers.
Note: Only records with latitude and longitude coordinates are plotted on map.

UASM10103 - Ennomos subsignaria

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, Medicine Hat Collected ByBowman, K. Date Collected1940-05-31

UASM99440 - Ennomos subsignaria

University of Alberta E.H. Strickland Entomological Museum

Place CollectedCanada: Alberta, CFB Suffield Collected ByAnweiler, G. G. Date Collected2008-08-13