|scientific name Nematocampa resistaria |
common name Bordered Thorn, Filament Bearer
Deciduous and mixedwood forests and woodlands.
Peak flight activity in Alberta is from late July to early August.
A small, tan geometrid with an intricate pattern of maroon lines, bands and venation. Forewing apex slightly falcate. This species is immediately recognizable; there are no other species like it in Alberta.
The common name Filament Bearer stems from the bizarre caterpillar of this species, which is able to evert two pairs of long tentacle-like structures dorsally on the abdomen (See Ives & Wong 1988, Wagner et al. 2001). The function of these structures is unknown, but perhaps is meant to mimic dead, dried flower parts or plant debris. Pupation occurs within a cocoon among plant foliage, and the egg hibernates (McGuffin 1987).
Not of concern.
Larvae are generalists on both deciduous and coniferous trees and shrubs. Often occurs on Douglas-fir (Pseudotsuga), hemlock (Tsuga), fir (Abies), spruce (Picea), willow (Salix), white birch (Betula papyrifera), hazelnut (Corylus); also low-growing plants such as strawberry (Fragaria) and carrot (Daucus) (McGuffin 1987).
BC to Nova Scotia, south to FL and CA (McGuffin 1987).
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