Entomology Collection TitleImage Bugs Pinned
Species Page - Celastrina ladon nigrescens
species list search results ->Celastrina ladon nigrescens ->species page

E-mail this Page   
Print this Page   
Link to this Page   

scientific name    Celastrina ladon nigrescens    

common name     Western Spring Azure

In Alberta, found only in montane meadows in the Castle River - Waterton region.

One brood, emerging in May to early June.

The Western Spring Azure lacks any trace of orange markings on the underside, and has a white-grey underside with black median and marginal dots. Very similar to the Boreal Spring Azure (C. ladon lucia), but in Alberta these two occur together only in the Castle River - Waterton Lakes region. The underside ground colour of nigrescens is lighter than lucia, and the upperside of males is violet-blue, not pale powder-blue as in lucia. Individuals of both species occasionally occur that have coalescent hindwing spots, resulting in a large blotch rather than a number of dots. The taxonomy of this group of species has been very confusing, and research is still ongoing to define the number of species and the appropriate names for this genus in North America; nigrescens and lucia do not intergrade but remain distinct where they occur together in BC and Alberta (Bird et al. 1995, Guppy & Shepard 2001, Schmidt unpubl. data), evidence that they are separate species rather than geographic forms of the same species.

life history
No data available for Alberta. On the west coast of BC, the eggs are white, and shaped like a slightly flattened sphere; mature larvae come in a variety of colours: green, purplish (Guppy & Shepard 2001) or white to pale pink with a transverse bar on the first abdominal segment (Ballmer & Pratt 1989). Tatum (2002) provides excellent photographs of pale yellow and wine-colored larvae and a mottled-brown pupa from Vancouver Island. Scott (1992) noted that although larvae can feed on a wide variety of flowers, females lay eggs on only a particular stage of the flower bud, and then only on species with a clustered flower structure, likely to ensure the larva has enough food to fully develop without having to relocate.

The Western Spring Azure is restricted to a small geographic area in Alberta.

diet info
No Alberta data. In BC, larvae feed on the flowers and developing seeds of ocean spray (Holodiscus discolor), Ceanothus (Ceanothus sp.) and hardhack (Spiraea douglasii) (Guppy & Shepard 2001). Of these, only Ceanothus velutinus occurs in Alberta (Moss 1992).

Southern BC and extreme southwestern Alberta south to Baja California (Bird et al. 1995, Guppy & Shepard 2001, Pratt et al. 1994).

quick link

Comments (0)Add New Comment

Comments are published according to our submission guidelines. The EH Strickland Entomological Museum does not necessarily endorse the views expressed.

Add New Comment (all fields are required)


Related Species Info
Display Hierarchy
References (7)
Specimen Info
There are 1 specimens of this species in the online database
Map Distribution
Adult Seasonal Distributioncreate a collection histogram with specimens
Specimen List (1)


Logo Department of Museums and Collections ServicesLogo University of Alberta