Author: (Denis and Schiffermüller, 1775)
Nut bud moth
Alder tortricid
Species Overview:
Adult: 12-16 mm wingspan; forewing of male with costal fold; ground colour cream-white, suffused and strigulated with ochreous; basal and sub-basal fasciae confluent; median and subterminal fasciae and pre-tornal marking ferruginous; median fascia narrow on costa; costa with several plumbeous striae present at costa. Hindwing light fuscous, darker apically; cilia whitish grey, with a dark sub-basal line. The predominantly ferruginous general colouration of the forewing is characteristic of this species.
Egg: 0.63 x 0.55 mm, brownish yellow, oval; deposited singly or in groups of two or three on the buds.
Larva: head prothoracic plate and thoracic legs dark brown, plate mottled with blackish, paler anteriorly; abdomen light greyish green or yellowish green; pinacula shining brown; anal plate light brown; anal comb present. In early instars the head, prothoracic plate and thoracic legs are black, the plate edged with greyish anteriorly, and the abdomen is whitish green.
Pupa: light brown; frons convex between antennae; apex of forewing pointed; spines near anterior margin clearly bigger than those near posterior margin; anal segment with 2 pairs of hooked setae dorsally and 1 pair of setae ventrally; ventral rim often double, not longitudinally wrinkled. In a flimsy silken cocoon amongst dead leaves on the ground or under moss.
Taxonomic Description:
Male:
Epinotia tenerana adult
Epinotia tenerana adults
External characters: 12-16 mm wingspan. Forewing with costal fold reaching to near middle of costa; ground colour cream-white, extensively suffused and strigulated with ochreous, the suffusion being very variable and sometimes forming a quadrate blotch on the dorsum between the basal patch and median fascia; basal and sub-basal fasciae confluent, forming a ferruginous-fuscous basal patch, obsolescent and suffused with plumbeous costally, indistinctly strigulated with black, its outer edge obtusely angulated and sometimes darkened with black; median and subterminal fasciae and pre-tornal marking ferruginous; median fascia narrow on costa, dilated medially, confluent with pre-tornal marking which sometimes has a blackish admixture; subterminal fascia arising from near tornus, coalescent medially with median fascia; several plumbeous striae arising from costal strigulae; a weakly developed ocellus consisting of three or four black dashes, which are often reduced to dots or absent, on an ochreous patch edged with submetallic whitish or plumbeous strigulae; cilia cream-white, suffused with grey, with a fuscous sub-basal line becoming weak towards tornus, and a whitish subapical dash extending onto termen. Hindwing light fuscous, darker apically; cilia whitish grey, with a dark sub-basal line (Bradley et al., 1979).
male genitalia E. tenerana
Genitalia: Uncus broad, apex bifurcate; upper fultura present in form of two ribs extending from base of socii towards aedeagus, socii broad, triangular, entirely bristled. Valva narrow, without deep notch in ventral margin, neck of valva indistinct.
Female:
External characters: Similar to male; without costal fold.
female genitalia E. tenerana
Genitalia: Ovipositor short; anterior part of sterigma (lamella antevaginalis) weak; lamella postvaginalis well developed, triangular; antrum relatively large; cingulum situated anterior to middle of ductus bursae, ductus seminalis originating here; corpus bursae with two signa, one of them very small (Bradley et al., 1979).
Variation:
The quadrate blotch on the dorsum may be only weakly suffused and very conspicuous, or it may be obliterated by a ferruginous suffusion which extends over most of the wing and obscures the markings.
Biology:
In the UK, moths fly from July to September or early October. Females deposit their eggs singly or in groups of two or three on the buds of the food plant, which then hatch in about a month. Larvae occur from October to April or May, living in the catkins of the food plant until the spring, often causing slight distortion, then moving into the developing leaf buds, making a hole at the base of the bud. Pupation occurs in June, in a flimsy silken cocoon amongst dead leaves on the ground or under moss.
Epinotia tenerana is recorded to a bivoltine species in the Netherlands, moths flying from May to June and in August. In Poland, moths are recorded to fly from June till August, or even September (Bradley et al., 1979; Führer, 1978; Bentinck and Diakonoff, 1968; Razowski, 1987b).
Host plants:
Corylus (hazel) and Alnus (alder); also on birch (Betula) and rarely on oak (Quercus).
Damage:
Larvae live in the catkins of the food plant until the spring, often causing slight distortion, then move into the developing leaf buds, making a hole at the base of the bud.
Distribution:
Europe to Eastern Russia, China, Korea and Japan.
Pheromone:
Pheromone unknown.
Attractantia:
E 10E 12-14Ac : 1
Z 10Z 12-14Ac : 1
(Witzgall et al., 1996b)
Parasitoids:
Eubadizon extensor Linnaeus (Braconidae)
1. Epinotia immundana (Fischer v. Röslerstamm)
Epinotia immundana adults; male gen. E. immundana; female gen. E. immundana
Epinotia immundana (Fisher von Röslerstamm) is also known to cause slight damage on catkins of white and black alder (Alnus incana, Alnus glutinosa) (Distribution: Northern and Central Europe to Russia).
Often there is a conspicuous white, subtriangular, patch present on dorsum, but this white patch can also be obscured.
Male genitalia: Socii less broad than in Epinotia tenerana; uncus more deeply incised apically; tuba analis spined.
Female genitalia: Lamella postvaginalis triangular; antrum not sclerotized; cingulum relatively large.
2. Epinotia tetraquetrana (Haworth)
Epinotia tetraquetrana adults; Epinotia tetraquetrana adult; male gen. E. tetraquetrana; female gen. E. tetraquetrana
Another species feeding on Alnus is Epinotia tetraquetrana (Haworth). Young larvae bore into a twig and cause an inconspicuous thickening or swelling in which it remains until the last instar; it then vacates the boring and lives within the shelter of a turned down edge of a leaf (Distribution: Northern and Central Europe to Mongolia and Eastern Russia).
Adults are generally lighter in colour; in Epinotia tetraquetrana the medial angulation of the outer edge of the basal patch is obtuse, where as in Epinotia immundana it is acute.
Male genitalia: The sacculus is angulated and densely bristled terminally; the cucullus is relatively broad.
Female genitalia: Lamella postvaginalis elongated.