Author: (Clerck, 1759)
Spruce needle tortricid
Adult: 10-13 mm wingspan; forewing of male with costal fold; ground colour white, usually strigulated with dark brown; markings brown; median fascia confluent with a fasciate pre-tornal marking; subterminal fascia arising from near tornus and extending to subapical area and costa. Hindwing fuscous-brown. A variable species: dark specimens are almost uniformly blackish brown.
Egg: 0.6-0.7 x 0.5 mm, yellowish white at first, turning brownish red or greyish later; deposited at the underside of the needles, inside lower crown parts. In dense stands also in higher crown parts.
Larva: 9 mm long; head light to dark brown; prothoracic plate dark brown or black; abdomen white tinged with pink, with reddish brown to bright red subdorsal lines; pinacula light brown, those on thoracic segments brown. Young larvae without subdorsal lines.
Pupa: 3-6 mm long; light yellowish brown; frons broad, weakly arced; apex of forewing relatively blunt; spines on abdominal segment 2 smaller than those on abdominal segment 3; spines near anterior margin clearly bigger than those near posterior margin on abdominal segments 3-7; dorsal spines on anal segment clearly bigger than those on 8th and 9th abdominal segments, and lateral spines clearly bigger than dorsal spines; anal segment with 2 pairs of hooked setae dorsally and 1 pair of setae ventrally; without ventral rim. Spun up in a silken cocoon amongst leaf litter on the ground [details pupa E. tedella ].
Epinotia tedella adult
Epinotia tedella adults
External characters: 10-13 mm wingspan. Forewing with costal fold reaching nearly to middle of wing. Labial palpus and head cream-white, lateral tufts on crown suffused with grey. Forewing ground colour white, with usually sparse, sharply contrasting, dark brown strigulation; markings brown to blackish brown, contrasting with ground colour, variably sprinkled with white and sometimes forming a weak reticulate pattern distally; basal and sub-basal fasciae well defined; sub-basal fascia broad, its outer edge obtusely angulated medially; median fascia moderately broad, outward-oblique from costa to near middle, thence angled inwards to dorsum, confluent with a fasciate pre-tornal marking which extends to or beyond middle; subterminal fascia arising from near tornus and extending to subapical area and costa, sometimes confluent with pre-tornal marking medially and enclosing a whitish patch of ground colour in ocellar area which contains a vestige of the tornal marking; cilia white, suffused with grey, with a black sub-basal line and a conspicuous, white subapical dash extending onto termen. Hindwing fuscous-brown; cilia paler, with a dark sub-basal line (Bradley et al., 1979).
male genitalia E. tedella
Genitalia: Uncus long, apex bifurcate; upper fultura present in form of two ribs extending from base of socii towards aedeagus, socii long. Valva narrow, without deep notch in ventral margin, neck of valva indistinct; sacculus angulated, spined. Aedeagus broad.
External characters: Similar to male; without costal fold.
female genitalia E. tedella
Genitalia: Ovipositor short; lamella antevaginalis weak; lamella postvaginalis well developed, elongate, slightly broadening posteriorly; antrum very short; cingulum situated postmedially in ductus bursae, ductus seminalis originating here; corpus bursae with two signa of about equal size.
There is considerable variation in the markings and clarity of the ground colour. Typically the black-brown markings contrast sharply with the white ground colour and are clearly fasciate, but often they are broken and fractured and in extreme forms the wing has a reticulate appearance. Sometimes the white ground colour is subdued with grey suffusion and the markings are blurred; in extreme forms the suffusion is heavy and the whole wing is almost uniformly blackish brown, the markings being hardly discernible (Bradley et al., 1979).
Epinotia tedella is a univoltine species with the main flight period in June and July. Moths are active during daytime: they prefer to fly at temperatures between 13 and 20°C. Flight activity increases during evening dusk. Oviposition also is influenced by the weather and the conditions in the tree stand. In more open stands, eggs are laid in the inside of the lower crown parts, but in denser stands, oviposition also occurs in higher crown parts. The eggs are mainly deposited at the underside of the needles. Thick needles on densely foliated shoots are preferred to thin needles on less densely foliated shoots. Adult females live at least 10 days. Embryonic development is completed in about 10 days at 21°C under laboratory conditions. After hatching, the larvae penetrate into the parenchyma of a needle and mine from the base toward the needle top, sparing the central vascular bundle. Unarranged spinning threads are pulled from the front of the mine entrance towards neighbouring needles. The excrements are red and are piled up above the entrance in a dome-like fashion. The larvae subsequently excavate 12-22 adjacent needles in the direction of the shoot tip during the course of their development (extreme values of up to 60 needles are found in the literature). The needles, first pale, then reddish brown, remain hanging on the branches together with the excrements, until they fall off the trees in the next winter. Late instar larvae often do not stay in the mines, but in a silken tunnel next to the main shoot. They then feed in particular on thin needles, often superficially. In case of shortage of food, migration occurs towards higher parts of the crown. The larvae then spin very industriously, leaving the host plant often densely covered by webs in times of heavy infestations. Between October and December, as soon as the daily temperature drops below 5 °C, the larvae descend from the last feeding site. A grey web of about 6-7 mm long, which is hard to find, is spun in the top layer of the needle litter. The larvae enter diapause and overwinter in these cocoons. Pupation occurs from mid April to the middle of May, depending on weather, elevation and crown density in the stand. The pupal stage lasts 5-6 weeks (Bogenschütz, 1991).
Picea excelsa; also on Picea sitchensis, Picea alcockiana and Picea bicolor. Mature larvae are also observed on Larix decidua, Pseudotsuga menziesii and Pinus sylvestris, but they cannot complete development on these hosts. Records of Abies alba and Juniperus are doubtful.
damage by E. tedella
Bud formation is not hampered, and flushing is normal or slightly retarded and weakened in the following year, as the intensive feeding of the larvae on the host plant does not start until autumn. However, growth is distinctly reduced in the following years. Branches in the lower parts of the crown of older spruce trees may occasionally die off. In young stands, entire trees may sometimes die after a second, serious infestation.
Outbreaks of Epinotia tedella occur mainly on soils of low quality, when the water economy of the host plant is poor, in particular in wind-protected stands on warm slopes. Spruces of any age are attacked. Infestation in harvest-ripe stands is usually limited to the lower crown parts; in pole wood stands the higher crown parts are attacked, while complete defoliation may occur in young trees. The structure of the needles determines their suitability for the larvae: less suitable needles have an epidermis with thick cell walls and a highly sclerotized hypodermis.
Outbreaks of this species last in general only 2 years. Especially after the culmination, egg and larval parasitoids and fungus diseases cause a high mortality, and thus contribute substantially to a rapid termination of the outbreaks (Bogenschütz, 1991).
Northern and Central Europe (secondary mountain chains and in the Alps, as well as in artificially planted areas) to Western Russia.
Optimal conditions for development are found in Germany, Austria, Switzerland and Czechoslovakia.
Z 7Z 9-12Ac : 0.4 *
Z 7Z 9- 12OH : 0.4
(Priesner et al., 1989)
Component marked with * is involved in attraction.
E 9-12Ac : 9
Z 9-12Ac : 1
(Booij and Voerman, 1984a)
Trichogramma evanescens Westwood (Trichogrammatidae)
Trichogramma embryophagum Hartig (Trichogrammatidae)
Lissonota dubia Holmgren (Tachinidae)
Apanteles tedellae Nixon (Braconidae)
Other species of Epinotia associated with Picea, not included in the species list:
1. Epinotia subsequana (Haworth)
Epinotia subsequana adult 1; Epinotia subsequana adult 2; male genitalia E. subsequana ; female genitalia E. subsequana
Forewing of male without costal fold; hindwing white, infuscate in apical third; male antenna not biciliate-fasciculate.
Male genitalia: Socii triangular, distally covered with setae; valva slender, ventral margin with deep notch.
Female genitalia: Signa very small.
Larvae feed on Picea and Abies (Europe to South-Western Russia).
2. Epinotia granitana (Herrich-Schäffer)
Epinotia granitana adult 1; Epinotia granitana adult 2; male genitalia E. granitana; female genitalia E. granitana
Forewing of male without costal fold; ground colour pale grey, reticulate with blackish.
Male genitalia: Socii long, without setae; valva slender.
Female genitalia: Lamella antevaginalis consisting of two joining elongate sclerites; signa slender.
Larvae are predominantly found on Abies, rarely also on Picea (Northern and Central Europe to Western Russia and Kazakhstan).
3. Epinotia fraternana (Haworth)
Epinotia fraternana adults; male genitalia E. fraternana; female genitalia E. fraternana
Forewing of male with costal fold; ground colour silvery white, markings vary from tawny to brown.
Male genitalia: Ventral margin of valva with notch; socii long.
Female genitalia: Lamella postvaginalis elongate, rounded caudally.
Larvae are recorded from Abies spp., Picea spp. and Pinus sylvestris (Central and South-Western Europe to South-Western Russia).