706 Agonopterix nervosa
(Haworth, 1811)Wingspan 16-22 mm.
One of the commonest Agonopterix species throughout Britain, readily coming to light from July to September. Some, at least, overwinter as adults and may appear at light in mid-winter.
The adults vary, but the forewing usually has a distinct whitish band curving from the base of the wing along nearly half of the costa. However, other species share this feature, so examination of the genitalia is suggested for specimens not reared from larvae on the correct foodplants. Fresh adults often have noticeably pink or purplish legs when viewed from certain angles.
The larva feeds in May and June from lightly spun shoots of broom (Cytisus scoparia), gorse (Ulex), Dyer's greenweed (Genista tinctoria), Petty whin (Genista anglica) and Tree lupin (Lupinus arboreus). It is the larval species most frequently found when beating the foodplants in season. Late instar larvae occur in several distinct colour forms; green, yellowish brown, brown and dark brown, which need care in distinguishing from larvae of several other species on the same foodplants (see below).