|scientific name Syngrapha octoscripta |
common name Dusky Silver Y
Dry coniferous and mixedwood boreal forest; dry, sandy grasslands.
Adults have been collected in Alberta from early July to late August.
A medium-size moth (3.4-3.6 cm wingspan) with dark grey and black forewings and buff-brown hindwings. Forewings are mostly black, with grey mottling in the basal area and extending along the costa to about the subterminal line. The stigma is a fine, open silver U with a separate hollow silver spot or ring just distad, usually joined by the arm of the U. There is a smallpatch of red-brown scales just beyond the stigma. Hindwings are buff-brown, shading into a wide, dark terminal band. The fringes on all wings are finely scalloped and checkered grey and black. Antennae are simple and both the sexes are similar. Very similar to S. interrogationis and some specimens of S. alias, and where these other species occur positive identification may require examining the genitalia. The pre-apical spine on the male valve of octoscripta is diagnostic and can usually be seen without resorting to dissection. There are additional diagnostic genitalic characters in both sexes, illustrated in the references listed below.
The Dusky Silver Y is nocturnal and comes to light. There is a single brood each year.
A fairly common, widespread species; no obvious concerns.
No Alberta data; elsewhere, blueberry (Vaccinium sp.). Populations in the grasslands of southern Alberta and Saskatchewan must utilize a different host, perhaps Bearberry (Arctostaphylos), as blueberry does not occur in these areas.
Newfoundland west to central Alaska and Vancouver Island, from treeline in the north south to the southern Prairie provinces in the west and Wisconsin, Ohio, Pennsylvania and New Jersey in the east. In Alberta, it has been collected from Lake Athabasca and Zama south throughout the boreal forest and in the foothills to about Calgary. It has also been collected in the Grasslands region, in the Red Deer River at Dinosaur Provincial Park and in the South Saskatchewan River, south of Empress.
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