Type

Exotic

Taxonomy

Tortrix viridana Linnaeus (Tortricidae: Tortricinae: Tortricini)

Common names: European oak leafroller, green oak tortrix

Synonyms: coeruleana (Tortrix), flavana (form), pflegeriana (form), suttneriana (Tortrix)

Adult Recognition

FWL: 8.0-11.0 mm

Forewing unmarked, uniformly green. The exact color varies from bright green to dull pale green, and some individuals have dull-yellow forewings, a condition that can also be caused by exposure of specimens to various killing agents and prolonged sunlight.

Male genitalia are distinguished by the following characters: uncusuncus:
a sclerotized process which is fused to the posterodorsal margin of tergum IX
absent; sociisocii:
a pair of lightly sclerotized setose lobes
large; valvavalva:
an appendage flanking the intromittent organ that is used to clasp the female during copulation
sub-rectangular with well developed sacculussacculus:
the ventral margin of the male valva
. Female genitalia are characterized by broad papillae analespapillae anales:
the female ovipositor lobes
with a patch of flat-headed setae, short apophysesapophyses:
apodemal rods used to extend the ovipositor; divided into the apophyses anteriores and apophyses posteriores
, a long ductus bursaeductus bursae:
a membranous tube connecting the ostium bursae to the corpus bursae
, and a small signumsignum:
a sclerotized projection or patch on the interior of the corpus bursae
in the corpus bursaecorpus bursae:
a dilated membranous sac at the anterior end of the bursa copulatrix
.

Larval Morphology

The following account is summarized from Bradley et al. (1973).

Late instar larvae are approximately 15-20 mm long with a green to gray abdomen. The head varies in color from brown to black and the prothoracic shieldprothoracic shield:
a sclerotized plate on the dorsal surface of the prothorax
varies from near-translucent to black. Darkened pinaculapinacula:
flattened sclerotized plates on a caterpillar that bear the setae
, which are more prominent near the anterioranterior:
before, to the front, toward the head
end of the abdomen and on the thorax, serve to separate this species from many North American tortricid larvae. Other diagnostic characters include black thoracic legs and an anal combanal comb:
a toothed structure on the last abdominal segment used to eject frass away from the feeding larva; also termed "anal fork"
with eight teeth.

A detailed description of larval chaetotaxychaetotaxy:
the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
is available in Swatschek (1958)Swatschek (1958):
Swatschek, B. 1958. Die larval systematik der wickler (Tortricidae und Carposinidae) aus dem zoologischen Institut der Universitat Erlangen. Akademie-Verlag, Berlin. 269 pp. [Abhandlungen zur larvalsystematik Insekten 3.]. 

Similar Species

Adults of this species are unlikely to be confused with any other tortricid. In Europe, T. viridana is similar both in size and coloration to Earias clorana (Nolidae).

Biology

The following account is summarized from Bogenschütz (1991).

Tortrix viridana typically completes a single generation per year. In warmer regions, two generations can occur. Adults are present from May until early July over most of its range.

Females lay eggs during June and July in the crown of the host tree; eggs are laid in pairs for a total of 50-60 per female. Reproduction may be able to occur parthenogenically (du Merle 1999du Merle 1999:
du Merle, P. 1999. Deacute;veloppement partheacute;nogeacute;neacute;tique chez la Tordeuse verte du checirc;ne, Tortrix viridana L. (Lepidoptera, Tortricidae). Bulletin de la Socieacute;teacute; Entomologique de France. 104: 85-90.). The eggs overwinter and larvae hatch the following April and May. First instar larvae feed on open buds and subsequent instars feed on the leaves. Larvae complete five instars and pupation occurs in a folded leaf.

Oak (Quercus sp.) is the primary host and in outbreak conditions T. viridana can cause extensive defoliation of oak trees. Defoliation affects tree growth, reproduction, and increases the chances of damage by other insects and frost. This species is regarded as one of the most important tortricid forest pests in southern Europe.

Secondary hosts include blueberry (Vaccinium sp.), nettle (Urtica sp.), and possibly other species not listed here; records on Norway spruce (Picea abies), poplar (Populus sp.), and raspberry (Rubus sp.) could not be verified.

Host plant	Host plant family	Reference(s)
Acer sp.	Aceraceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Carpinus betulus	Betulaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Vaccinium sp.	Ericaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Fagus sylvatica	Fagaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Quercus ilex	Fagaceae	du Merle 1981du Merle 1981: du Merle, P. S. 1981. Variabilite genetique et adaptation a lrsquo;hote chez Tortrix viridana L. (Lep., Tortricidae). Compter. Acad. Sci. Paris (Ser. III) 292: 519-522.
Quercus pubescens Willd.	Fagaceae	du Merle 1981du Merle 1981: du Merle, P. S. 1981. Variabilite genetique et adaptation a lrsquo;hote chez Tortrix viridana L. (Lep., Tortricidae). Compter. Acad. Sci. Paris (Ser. III) 292: 519-522.; du Merle & Mazet 1992; Hunter et al. 1997Hunter et al. 1997: Hunter, M. D., Varley, G. C., Gradwell, G. R. 1997. Estimating the relative roles of top-down and bottom-up forces on insect herbivore populations: a classic study revisited. Proceedings of the National Academy of Sciences. 94: 9176-9181.
Quercus robur	Fagaceae	Disque 1908Disque 1908: Disque, H. 1908. Versuch einer microlepidopterologischen Botanik. Deutsch Entomologische Zeitschrift Iris. 21: 34-147.; Hunter 1987Hunter 1987: Hunter, M. D. 1987. Opposing effects of spring defoliation on late season oak caterpillars. Ecological Entomology. 12: 373-382.; Hunter et al. 1997Hunter et al. 1997: Hunter, M. D., Varley, G. C., Gradwell, G. R. 1997. Estimating the relative roles of top-down and bottom-up forces on insect herbivore populations: a classic study revisited. Proceedings of the National Academy of Sciences. 94: 9176-9181.
Quercus suber	Fagaceae	Hunter & Wilmer 1989; Villemant & Fraval 1993
Quercus sp.	Fagaceae	Meyrick MS 1938Meyrick MS 1938: Meyrick MS 1938. Unpublished manuscript by E. Meyrick at BMNH, data captured by Gaeden Robinson.; Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.; Nuorteva et al. 1987Nuorteva et al. 1987: Nuorteva, P., Z. Whitkowski amp; S.-L. Nuorteva. 1987. Chronic damage by Tortrix viridana L. (Lepidoptera, Tortricidae) related to the content of iron, aluminum, zinc, cadmium and mercury in oak leaves in Niepolomice Forest. Ann. Entomol. Fenn. 53: 36-38.; Emmet 1992Emmet 1992: Emmet, A.M. 1992. Life history and habits of the British Lepidoptera. Pp. 61-300. In : Emmet, A.M., Heath, J. (eds.), The Moths and Butterflies of Great Britain and Ireland, 7. 400 pp., Harley Books, Colchester.; Kompanitsev & Ivashov 1993; Lobinger & Skatulla 1996; Jurc 2006
Prunus armeniaca	Rosaceae	BMNH collectionBMNH collection: BMNH collection. Based on identified reared specimens in the collection of The Natural History Museum, London; identifications by staff of the Lepidoptera Section.
Populus sp.	Salicaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Salix sp.	Salicaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.
Urtica sp.	Urticaceae	Bradley et al. 1973Bradley et al. 1973: Bradley, J. D., Tremewan, W. G., Smith, A. 1973. British Tortricoid Moths, Cochylidae and Tortricidae: Tortricinae. The Ray Society, London. 251 pp.

Host plant table (embedded)

View full screen host table here

Distribution

Tortrix viridana is found in Europe, Asia Minor, the Middle East, and northern Africa.