|scientific name Macaria loricaria |
common name False Bruce Spanworm
Generally common in mixedwood and deciduous forests.
Late June to late July, peaking in mid July.
A pale grey geometrid with indistinct markings. AM, PM and median dark lines usually present, the PM widest and slighltly darker. Patchy brown band distal to the PM band variably developed. Discal spot usually well-defined. Hindwings paler than the forewings, PM band usually visible. Females have vestigial wings and are flightless.
Similar to I. anataria and exauspicata; loricaria males have larger antennal pectinations giving a more feathery appearance, and females have vestigial wings. The forewings of exauspicata are also wider, and lack the more pronounced concavity of the forewing apex of anataria, giving the latter more notched appearing forewings. The forewing costal marks of loricaria are concolourous with the transverse lines, not darkest at the costa as in anataria and exauspicata.
This species is Holarctic; North American populations are subspecies julia (Hulst).
The immature stages are described by McGuffin (1972). Handfield (1999) notes that adults come to light, and are also occasionally attracted to sugar bait. One of the more common Itame species in Alberta.
Not of concern.
The principal larval host is trembling aspen (Populus tremuloides) (Prentice 1963).
Alaska to Newfoundland and New York, south to Colorado (McGuffin 1972).
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