Cnephasia longana

Author: (Haworth, 1811)

Omnivorous leaf-tier

Species Overview:

Adult: 15-22 mm wingspan; forewings pale ochreous to brownish ochreous in male, whitish ochreous with yellowish brown markings in female; hindwings translucent grey.
Egg: salmon pink, flat and oval; laid singly or in small batches on the food plant or on rough surfaces of trees, posts and similar situations, in crevices and depressions. Eggs are brushed by the papillae analis while still sticky, causing scales and particles of debris to adhere.
Larva: 14-18 mm long; rather plump; greenish grey or yellowish grey, with pale longitudinal lines along the back and sides; head light brown, region of stemmata and postero-lateral margin dark brown; prothoracic plate light brown or greenish; anal plate light brown; anal comb light brown, with 6-8 long prongs [Cnephasia longana larva].
Pupa: 7-8 mm long; light brown; in a flimsy cocoon amongst surface debris, dead leaves or in empty seed capsules [C. longana pupa (Limonium) ].

Taxonomic Description:

Male:

Cnephasia longana male 1
Cnephasia longana male 2
Cnephasia longana male 3
External characters: Antenna very shortly ciliate. Costal margin of forewing slightly arced, apex rounded, termen oblique. Ground colour unicolorous, pale ochreous to brownish ochreous; cilia concolorous. Hindwing pale translucent grey; cilia paler. Anal tuft well developed (Bradley et al., 1973).

male genitalia C. longana
Genitalia: Valva tapering apically, curved outwards; sacculus reaching just a little beyond one-third of the length of valva; uncus long; socii narrow, fairly long; gnathos terminating into a very broad plate; aedeagus bent, with large spinules on right wall.

Female:

Cnephasia longana female 1
Cnephasia longana female 2
Cnephasia longana females
External characters: Forewing ground colour whitish ochreous, diffusely irrorate with ochreous-brown; markings ochreous-brown; sub-basal fascia sharply angulate medially; median fascia from beyond middle of costa to before tornus, its inner margin deeply indented above and below middle; pre-apical spot diffuse; a broad subterminal stria. Hindwing as in male; cilia whitish (Bradley et al., 1973).

female genitalia C. longana
Genitalia: Lamella antevaginalis broad, abruptly narrowing; its caudal margin deeply incised medially; its proximal margin rounded.

Variation:

In the male the forewing varies from whitish grey to dark ochreous-brown; very rarely the darker forms have a sprinkling of blackish scales. The female shows similar variation in ground colour, with the markings varying from light ochreous-brown to dark ochreous-brown with an admixture of fuscous or black; heavily marked specimens are sometimes distinctly grey in general appearance and the markings are diffuse. Weakly marked almost unicolorous pale forms of the female occur rarely. In both sexes the hindwing varies from whitish to dark grey.

Biology:

Adults occur in July. Eggs are then laid singly or in small batches on the food plant or on rough posts and tree trunks. They hatch in late July or in August. After devouring its egg shell, each tiny larva crawls away and then spins a silken cocoon in which to overwinter. In early spring, the larvae leave their hibernacula to begin feeding, often being dispersed by wind to other plants after producing a fine silken strand. The larvae feed in spun leaves, especially on terminal shoots, webbing the foliage tightly together. They also attack flowers and blossom trusses, and may also bore into the shoot tips. Pupation occurs in June within a flimsy cocoon in debris on the ground or amongst dead leaves. Moths emerge two to three weeks later (Alford, 1984; Glas, 1991).

Host plants:

The larvae are polyphagous on many low-growing plants, but are most often associated with members of the Compositae, including Chrysanthemum, Aster and Pyrethrum, and can sometimes be found on glasshouse flowers. It is a pest of certain economical importance on wheat (Triticum), barley (Hordeum), rye (Secale) and oat (Avena). It has also been recorded from cultivated field beans (Vicia), hop (Humulus), filbert (Corylus), flax (Linum), tomato and sugar beet. Although not an important fruit pest, this species has also been reported attacking apple (Malus), pear (Pyrus), black currant (Ribes), raspberry (Rubus) and strawberry (Fragaria).

Damage:

C. longana damage on pear tree
Direct damage to foliage is unimportant but, on apple and blackcurrant, larvae tunneling into shoots cause considerable disruption of growth. On strawberry, larvae commonly attack the flowers, causing death or the development of malformed fruits. Infestations are most likely to occur in weedy orchards and plantations.
On cereals the larvae mine in narrow oblong passages, feeding on the parenchyma tissue between the upper and lower epidermis, later leaving the mines and continuing to feed on the leaves by folding and spinning the leaf margins towards the central veins. From the beginning of the formation of the ears, the sheath of the flag leaf is penetrated by the larvae and stamens and pistils are destroyed. In some cases, even stalks are cut.
In North America, it has become a serious pest on cultivated strawberry (boring into the fruit), flax, vetch and other plants (Alford, 1984; Glas, 1991; Bovey, 1966).

Distribution:

Europe to Asia Minor; North-Western Africa and the Canary Islands. Also occurs in Western North America where it was recorded in 1929.

Pheromone:

Z 9-12Ac

Attractantia:

Z 9-12Ac : 1
Z 9-12OH : 1 (Booij and Voerman, 1984a)

Parasitoids:

record from Europe:
Itoplectis maculator (Fabricius) (Ichneumonidae)
Trichogramma evanescens (Westwood) (Trichogrammatidae)

records from USA:
Microbracon gelechiae (Riley) (Braconidae)
Microbracon hyslopi Vier. (Braconidae)
Meteorus argyrotaeniae (Braconidae)
Phytodietus burgessi Cress. (Ichneumonidae)
Glypta sp. (Ichneumonidae)
Dioetis eureka Ashm. (Ichneumonidae)

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