Synonyms and other taxonomic changes
Adela trigrapha Zeller 1875 Original Description:
Verh. Zool.-Bot. Ges. Wien, 25:342 (
Fig. 50)
Adela trifasciella Chambers 1876 Original Description:
Canad. Ent. 8:103; synonymy from Walsingham 1880,
Proc. Zool. Soc. Lond. :79 Plate XI, Figs. 2,3
Adela fasciella Chambers 1876 Original Description:
Canad. Ent. 8:103; synonymy from Walsingham 1880,
Proc. Zool. Soc. Lond. :79 Size
Forewing length 5.5 - 6.2 mm, some inland populations smaller (FWL 4.5 - 5.5 mm); females smaller than males
(1)Identification
Adults
(1)(2): Body black; forewing black crossed by three white transverse lines...reduced to two or only traces in some populations. Hindwings black with purplish-bronze highlights and two inconspicuous, equally-spaced, white spots along terminal edge within proximal half. Antennae appear mostly white (especially on distal half or more, proximal segments appear black-banded with fine, white-reflective pubescence).
Males have head black; large eyes (eye diameter 3 times or more the distance between eyes at top of head); and longer antennae (3 or more times forewing length).
Females have and bright orange heads; much smaller eyes (diameter about 2/3 distance between eyes), and shorter antennae (1.5 X FWL).
Range
Vancouver Island to southern California, including Santa Rosa and Santa Cruz Islands
(1).
Recorded at elevations < 2000' in the Sierra Nevada, and < 4000' in the CA coast ranges.
(2)Season
March to mid-May in the CA foothills; mid-April to mid-June from Lake Co. northward.
(2)Food
Larval host plants are species of
Leptosiphon (Polemoniaceae). Adults of both sexes visit other plants for nectar, especially Asteraceae
(1).
Remarks
Perhaps the most commonly seen species of
Adela. Males are often seen in small dancing groups in open flowery meadows
(1)See Also
A. eldorada: Described from mid-montane Sierra Nevada Mountains of CA, with wider wing bands; males with conspicuous orange on heads.
A septenrionella: Both
A. trigrapha and
A. septentrionella can have their white markings reduced...in such cases they may be difficult to distinguish from one another.
Males of A. trigrapha have much larger eyes (diameter usually about 4 times distance between eyes at top of head) than those of A. septentrionella (diameter about 1.25 times distance between eyes).
Also, A. trigrapha is generally a more southerly species occurring at lower elevations (< 2000' in the Sierra Nevada; < 4000' in the CA coast ranges); whereas A. septentrionella is a more boreal species which can occur at higher elevations (up to timberline at 6000' in the Trinity Alps and 8000' in the Sierra Nevada of CA).
[Note: Above info summarized from Powell
(2)]
Internet References
Reference Plate for A. trigrapha from "Moths of Western North America" by Powell & Opler
(1)
