|scientific name Polites rhesus |
common name Rhesus Skipper
Short-grass prairie in the arid southeastern part of the province.
Adults occur in late May. One yearly brood.
The white maculation and white veins on the hindwing underside are similar to those of the Uncas Skipper (Hesperia uncas), but the Rhesus skipper is smaller and never has any orange markings on the upperside.
The early stages are not known in Alberta. Layberry et al. (1998) state that the larvae are undescribed, but the following description is given in Bird et al. (1995): The egg is pale green in colour, first instar larvae are cream-coloured with a black head, and mature larvae are either light grey-green or brownish green.
This species appears to undergo large yearly fluctuations in abundance; in South Dakota, the Rhesus Skipper was absent in localities where it was common the previous year (J.S. Nordin, cited in McCabe & Post 1977). This may be related to winter weather conditions, as populations of P. rhesus appear to occur in areas of little to no snow cover (Hooper 1973, McCabe & Post 1977). In 2000, the Rhesus Skipper was apparently more common than usual, and several new colonies were located (C. Schmidt unpubl. data).
Restricted range in Canada; Population survey and tracking work needed.
Colorado larvae feed on Blue Grama grass (Bouteloua gracilis) (Scott 1986). Adults take nectar at Astragalus flowers in North Dakota (McCabe & Post 1977).
A Great Plains species, found from southern Alberta and Saskatchewan south to Durango, Mexico (Opler 1999). This species was first reported in Canada from Saskatchewan specimens taken in 1971 (Hooper 1973), and in Alberta in 1977 (Bird et al. 1995). Recent examination of specimens in the Strickland Museum has led to the discovery of a specimen from Medicine Hat collected in 1928, previously misidentified as Hesperia uncas (C. Schmidt unpubl. data).
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