History of the northern silvery blue (Glaucopsyche lygdamus couperi) (Lepidoptera: Lycaenidae) in southern Ontario, Canada: separating range expansion from original populations and other subspecies

The historical distribution of Glaucopsyche lygdamus (Doubleday) (Lepidoptera: Lycaenidae) in southern Ontario, Canada was analysed using three major databases. In southern Ontario, G. lygdamus includes (1) subspecies G. lygdamus couperi Grote that has expanded its range from the north since the 1940s and 1950s reaching Hamilton, Ontario, Canada in 2012; (2) a non-expanding population on the Norfolk Sand Plain, Ontario, Canada that appears phenotypically closest to G. lygdamus couperi, but with some wing marking characters that are transitional to the more southern subspecies G. lygdamus lygdamus; and (3) rare and local pre-expansion populations referable to G. lygdamus couperi that occurred in the Ottawa Valley and Bruce Peninsula, Ontario, Canada in alvar woodlands, and possibly also on lakeshore dunes. The very rare and local occurrences of silvery blue in southern Ontario in the past is in direct contrast to its increasing abundance in the area in present times, but the genetic and phenotypic diversity of silvery blue may be declining due to genetic mixing with and/or to the effect of increasing parasitoids from the expanding race.

An alvar race of the couperi subspecies of the Silvery Blue (Glaucopsyche lygdamus couperi) in southeastern Ontario?

The couperi subspecies of the Silvery Blue (Glaucopsyche lygdamus couperi) has expanded its range southward in northeastern North America using introduced legumes and open anthropogenic habitats. The discovery of a population of the Silvery Blue (Glaucopsyche lygdamus) in an eastern Ontario alvar woodland in 2011 suggests that the Silvery Blue may have been long established (although restricted) in southern Ontario. Three larvae from this population were reared from eggs deposited on native Neglected Milk-Vetch (Astragalus neglectus) by free-flying females in 2012. The three larvae, pupae, and single reared adult, as well as other adults from the alvar woodland, are described and compared with specimens associated with open anthropogenic habitat and introduced legumes. The alvar woodland specimens were closer to the northern Ontario subsp. couperi than to the subsp. lygdamus of the eastern United States. Although the alvar woodland larvae were darker green than subsp. couperi and the spots on the adults were on average larger than in subsp. couperi, the alvar woodland Silvery Blues could not be definitively distinguished from subsp. couperi, including specimens from northern Ontario and those from southern Ontario associated with open habitats. Nevertheless, there is a possibility that the alvar woodland population of the Silvery Blue dates from early postglacial times and represents a distinct race separate from the Silvery Blue of open habitats.

A NEW RACE OF GLAUCOPSYCHE LYGDAMUS FROM THE WHITE MOUNTAINS, ARIZ. (LEPID., LYCAENIDAE)

Male. Characterized by thle broad black outer border on the upper-side of both wings, this border being frequently 2 mm. in width. The blue color on the remaining wing-area is very deep, and, although quite shiny in certain lights, is more the color of P. icnrioides, and much darker than in the other western races. On the underside the black spots are very large, and prominently white-ringed; the ground color is a deep gray-brown, rather reminiscent of the type form and darker than is usual in the Coloradan oro Scud. Fringes white.