|scientific name Amphipoea americana |
common name American Ear Moth
In Alberta it is collected commonly in the boreal forest and parklands region, as well as in wooded valleys in the grasslands.
A medium-size (2.8-3.5 cm wingspan) moth with rusty-orange forewings and grey-brown hindwings with an orange-brown fringe. The forewings are covered with a network of narrow faint dark lines along the veins and marking the normal lines and spots. The claviform, orbicular and occasionally the reniform spot are filled with lighter yellow-orange, but in a few instances the reniform is bright contrasting white. Almost identical to A. interoceanica, but most interoceanica have a white reniform whereas in most Alberta americana it is yellow or orange. The pale filling of the reniform of interoceanica, confined to the outer two-thirds of the reniform, is more extensive in americana. Specimens require an examination of the genitalia for positive identification. Both sexes can usually be examined without dissecting by brushing and looking for the long digitus on the valve of americana males, or the shape of the 7th sternite in females.
The adults are nocturnal and come to light. There is a single brood each year, flying in late summer and early fall. The larvae are borers in grasses and sedges, and in the USA americana has been reported as an occasional minor pest on young corn.
Widespread, but the precise range is difficult to ascertain due to the numerous frequent errors in identification. Bowman reported it from the foothills and mountains, but we have not seen specimens to confirm this.
Amphipoea americana is a fairly common moth throughout much of Alberta. However, specimens in collections are frequently misidentified, as the genitalia need to be checked for positive identification. Fortunately most specimens can be identified without dissection by brushing the scales off the end of the abdomen. Bowman reported all Alberta Amphipoea as A. interoceanica, although with very few exceptions all material in his collection, as well as that available to him in the Strickland Museum, is actually A. americana.
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