Author: (Hübner, 1799)
Hawthorn tortricid
Brown oak tortrix
Species Overview:
Adult: wingspan 19-22 mm in males, 23-28 mm in females; forewings light brown to brown with velvety chocolate-brown markings; median fascia obsolete on the costa in males. Hindwing brownish grey; in females apex sometimes tinged with yellow.
Egg: 0.6 x 0.4 mm; laid close to each other in a white cement-like substance in batches of about 30 eggs.
Larva: dark olive-green or black with black pinacula and long whitish setae; head and prothoracic plate shining black, prothoracic plate large, less shining than head; anal plate shining black, strongly convex anteriorly; anal comb black, with 6-8 prongs.
Pupa: 9-15 mm, dull blackish brown with shining black head and thoracic region; abdominal segments 2 and 3 with transverse folds dorsally, front margin of transverse fold of segment 2 with a conspicuous, almost circular process, connected with the hind margin; abdominal segments with some conspicuous hairs [details pupa Archips crataegana ]
Taxonomic Description:
Male:
Archips crataegana male
Archips crataegana males
External characters: 19-22 mm wingspan. Labial palpus pale brownish; head rather concolorous; thorax darker medially and proximally. Forewing with slender costal fold reaching to middle of costa; costa curved outwards to middle, nearly straight in apical portion; apex short, pointed; termen delicately sinuate postapically, then slightly convex. Ground colour pale brownish with greyish hue, brownish cream to dirty cream to basal blotch costally and often near the margins of the markings; markings velvety chocolate-brown. Median fascia atrophied at costa, angulate near middle, inner margin edged with whitish; subapical blotch extending from beyond middle of costa, rather short, with terminal part slender, subtriangular; cilia concolorous with ground colour, browner at apex and in apical part of termen, more cream towards tornus. Hindwing brownish; cilia whitish with brownish basal line (Razowski, 1977; Bradley et al., 1973).
male genitalia A. crataegana
Genitalia: Uncus slender, hardly expanding terminally; socius small; sacculus with strong free termination. Aedeagus pointed ventro-apically, provided with slender dorso-lateral process; two cornuti present in vesica.
Female:
Archips crataegana female
Archips crataegana females
External characters: 23-28 mm wingspan. Forewing broad; costa distinctly curved outwards especially in basal third, concave subapically; apex rather short, pointed; termen abruptly concave beyond apex (deepest point before vein M 1), then convex. Ground colour usually darker brown than in male, reticulate with dark fuscous; median fascia reaching costa, not edged with whitish inwardly. Hindwing brownish grey, apex sometimes tinged with yellow; cilia much paler than wing, with brownish basal line (Razowski, 1977; Bradley et al., 1973).
female gen. A. crataegana
Genitalia: Posterior part of sterigma short, broad, its caudal margin concave, without median process. Anterior part slender, slightly tapering anteriorly; cestum reaching to before end of ductus bursae, signum fairly small.
Variation:
In the male the forewing ground colour varies from dark grey to whitish ochreous, the markings usually remaining dark. In the female the ground colour varies from dark brown to light ochreous; the reticulation and markings vary in intensity and may contrast strongly with a light ground colour. When present, the yellowish suffusion at the apex of the hindwing varies in intensity and sometimes the apex may appear distinctly yellow (Bradley et al., 1973).
Biology:
Moths fly from the beginning of June to mid August. Their main flight period in Central Europe is usually in June. Emergence of the males starts before the females appear. The moths are active at twilight and at night and visit blossoms for food uptake. The first egg masses are deposited one week after emergence. The females prefer the south-eastern side of tree stems with a rough bark for oviposition. Eggs are laid in groups, in flat masses of mostly 30-40 eggs and are covered with a gland secretion, which hardens to a snow-white, foamy, substance. The greatest density of eggs is found at about 3 m above the basis of the trunk. Embryogenesis stops at the beginning of the winter, when temperatures decrease to below 5°C, but is resumed in the next spring when the developmental threshold is reached again (February). The embryos remain in quiescence during winter. The larvae hatch in about the middle of April until the beginning of May and crawl immediately to the crowns of the trees, where they start to feed in fine webs at the underside of the leaves. The leaf edges are rolled up after the larvae have reached the third instar. The larvae continue to feed in these shelters. In total, five larval instars are completed. Pupation occurs in a rolled leaf or between two leaves spun together, adults emerging a few weeks later (Bogenschütz, 1991).
Host plants:
Larvae feed on the foliage of Malus, Prunus, Pyrus, Fraxinus, Quercus, Acer, Betula, Crataegus, Mespilus, Populus, Tilia, Salix, Ulmus, Tilia and Sorbus (occasionally found on cultivated apple, pear, cherry and plum).
Damage:
Feeding is restricted mainly to the expanded leaves, and unless larvae are very numerous, damage is insignificant. During outbreaks they can cause considerable damage on oak. In the first instar, the larva feeds mainly on the under surface of the leaf; in later instars the edge of the leaf is rolled into a tight tube. Defoliation rate can be predicted on the basis of the density of egg masses on the bark of stems up to a height of 2 m. On oak, about 100 egg masses per stem indicate complete defoliation in 80-100-year-old stands. Exact infestation must be assessed after the penetration of the larvae into the buds, when heavy damage is expected. An average of two or more larvae per bud is usually sufficient to cause complete defoliation (Alford, 1995; Bogenschütz, 1991).
Distribution:
Northern and Central Europe, Asia Minor, Central Asia to Kazakhstan.
A typically woodland species.
Pheromone:
Z 11-14Ac : 18
Z 9-14Ac : 7.5
Z 11-14OH : 1
E 11-14Ac (Kovalev, 1990)
Attractantia:
Z 11-14Ac : 68
Z 9-14Ac : 28
Z 11-14OH : 3 (Kovalev et al., 1991)
Parasitoids:
Of egg:
Trichogramma cacoeciae Marchal (Trichogrammatidae)
Of larva:
Pseudoperichaeta nigrolineata (Walker) (Tachinidae)
Of pupa:
Itoplectis maculator (Fabricius) (Ichneumonidae)
Apechthis quadridentata (Thomson) (Ichneumonidae)
Apechthis rufata (Gmelin) (Ichneumonidae)
Apechthis resinator Thunberg (Ichneumonidae)
(Bogenschütz, 1991; Martinez and Reymonet, 1991)