Author: (Fabricius, 1794)
Broad-barred button moth
Species Overview:
Adult: 15-20 mm wingspan; forewings varying from silvery-white to ochreous or olive-yellow, suffused with grey and black, and marked with black, brown or red; hindwings grey. A very variable species.
Egg: greenish grey, flat and oval; deposited singly at the base of a bud of the food plant.
Larva: 12-15 mm long; head yellowish brown, region of stemmata and postero-lateral margin dark brown; prothoracic plate yellowish brown or brownish green, a well-defined darker subdorsal spot on the posterior margin; abdomen whitish green, pinacula concolorous [Acleris laterana larva].
Pupa: 8-9 mm; dark reddish brown; cremaster short and broad, end of cremaster with two sharp corners behind, four slender cremaster hooks and four slender anal hooks; in a silken cocoon spun up in a folded leaf or in the larval habitation [details pupa Acleris spp.].
Taxonomic Description:
Male:
Acleris laterana adult
Acleris laterana adults 1
Acleris laterana adults 2
External characters: 15-20 mm wingspan. Head, thorax and antenna brownish; abdomen pale brownish-grey. Forewing slightly expanding distally; costa bent outwards in basal third, slightly convex medially; apex of forewing short, slightly protruding. Ground colour varying from silvery-white to ochreous or olive-yellow, often diffusely strigulated with mixed grey and black scales; markings brownish red, or dull bluish black (in specimens with a yellowish brown ground colour); outer margin of basal fascia diffuse, or basal fascia obsolescent; sub-basal fascia developed on dorsum, diffusely confluent with basal fascia; costal blotch extending to tornus, inner edge well defined, outer edge diffuse (in specimens with silvery-white ground colour), or costal blotch well defined; terminal area often sprinkled with black; cilia grey. Hindwing brownish grey (after Bradley et al., 1973; Razowski, 1984).
male genitalia A. laterana
Genitalia: Tegumen delicate, strongly tapering apically, with small apical lobes ; socii long, broader anteriorly than posteriorly; tuba analis slender with well-developed subterminal plate. Valva long, costa strongly sclerotized; sacculus with rather flat excavation ventrally, the posterior edge of this rather straight, protruding ventrally, pointed; brachiola elongate. Aedeagus short with one long and numerous small cornuti.
Female:
External characters: Usually larger than male; forewing not expanding distally. Colour and markings as in male.
female gen. A. laterana
Genitalia: Sterigma broad with rather flat posterior edge, slightly protruding medially, and with long, slender, pointed terminally, anterior projections; ostium bursae rounded; antrum membranous, broad; ductus bursae long, thin; ductus seminalis rather posterior; corpus bursae elongate; no signum present.
Variation:
Acleris laterana is a very variable species. The intensity of the greyish suffusion on specimens with a silver-white ground colour may be sufficiently heavy to almost obliterate the ground colour. Often, the ground colour is suffused with grey, giving the wing a cinerous appearance, the basal fascia obsolescent, only a vestige of the sub-basal fascia, and the costal blotch lunate, rich red-brown or chestnut-brown.
The ground colour can also be pale yellow-brown varying to ochreous, with the costal blotch and sub-basal fascia dull bluish black. Another form has the ground colour grey-brown, varying considerably in shade, the costal blotch relatively inconspicuous, its inner margin extending across the wing in some specimens (after Bradley et al., 1973).
Biology:
According to Alford, 1984, this species is univoltine in England. Eggs are laid singly at the base of buds in late August and September. They hatch in the spring. The larvae then feed between spun leaves during May and June, and may also attack the flowers. Pupation occurs in July within a silken cocoon spun in a folded leaf, adults emerging about three weeks later.
According to Van de Vrie, 1991, this species has two generations yearly in Europe; adults flying from June to July, and from August to September. In greenhouses, a third generation may develop. In Japan and Korea, this species also has two generations yearly. Moths fly from May to June and from September to October.
Host plants:
Crataegus, Filipendula ulmaria , Populus, Prunus, Rosa, Rubus, Sorbus, Salix, Symphytum officinale and Vaccinium. Records of this species on Azalea and Rhohodendron probably concern Acleris comariana (Bradley et al., 1973).
Damage:
On blackberry, loganberry and raspberry, attacks on blossom trusses may cause fruit losses or malformation but the larvae are rarely numerous (Alford, 1984).
Distribution:
Palaearctic Region; accidentally imported into the USA.
Pheromone:
Pheromone unknown.