Enarmonia formosana

Status

ADVENTIVE

PORT INTERCEPT | DOMESTIC SURVEY

Taxonomy

Enarmonia formosana (Scopoli) (Tortricidae: Olethreutinae: Enarmoniini)

Common names: cherry bark tortrix

Synonyms: ornatana (Tortrix), scriptana (Tortrix), woeberana (Pyralis), woeberiana (Tortrix)

Adult Recognition

FWL: 7.0–9.0 mm

Forewings are black with distinctive yellow, orange, and silvery markings and a conspicuous ocellus with alternating black and yellow bands. Hindwings are dark grayish brown with a white fringe.

Male genitalia are characterized by a short, triangular uncus; triangular, setose socii; and relatively short valvae with a large basal cavity and single large, stout, ventrally directed seta at the apex. Female genitalia are characterized by single, triangular, blade-like signum in the corpus bursae. 

Larval Morphology

The following account is summarized from 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.].

Mature larva approximately 8–11 mm in length; head brown; prothoracic shield brown, sometimes marked with black on the posterolateral margin; body whitish to gray to pinkish with darker gray pinacula.

Similar Species

Adults of Enarmonia formosana have forewing coloration similar to some Olethreutes and related genera (Syricoris, Pristerognatha, etc.), although most of these species lack a defined ocellus. In North America, Eucosmomorpha nearctica may appear similar, but adults lack the black forewing ground color. A genitalic dissection can be used to easily separate the various genera listed here.

Enarmonia formosana pheromone traps in Washington have captured a wide variety of tortricines and olethreutines as well as moths in other families. Wing pattern is usually sufficient to separate E. formosana from non-target species.

Distribution

Enarmonia formosana is widely distributed from western Europe and northern Africa to Asia Minor, Russia, and Siberia. The first North American records are from British Columbia in 1989 (Dang and Parker 1990Dang and Parker 1990:
Dang, P. T., Parker, D. J. 1990. First records of Enarmonia formosana (Scopoli) in North America (Lepidoptera: Tortricidae). Journal of the Entomological Society of British Columbia. 87: 3-6.). It was subsequently found in western Washington in 1991 and has since spread to Oregon.

Biology

There are contradictory reports of the number of generations per year in the literature. In North America, there appears to be a single generation per year, but the species displays "some bimodal flight tendencies" (Breedveld and Tanigoshi 2006Breedveld and Tanigoshi 2006:
Breedveld, K. G. H., Tanigoshi, L. K. 2006. Seasonal phenology of Enarmonia formosana (Lepidoptera: Tortricidae) and egg parasitism by Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae) in Washington State, USA. Journal of Pest Science. 80: 15-19.). Peak numbers of adults are active from June to September.

The following account is summarized from Tanigoshi and Stary (2003)Tanigoshi and Stary (2003):
Tanigoshi, L. K., Stary, P. 2003. Distribution, habitats and host plants of the cherry bark tortrix, Enarmonia formosana (Scopoli) in the Czech Republic (Lepidoptera, Tortricidae). Journal of Pest Science. 76: 41-43..

Females lay eggs singly or in small clusters on tree bark. Larvae tunnel into the bark and feed under the surface. Older trees are usually more heavily infested; wounded tissue and the base of the tree are favored feeding sites. Larval damage is characterized by "frass tubes" consisting of fecal pellets, silk, and tree sap, which protrude from larval feeding sites. Overwintering occurs as a larva. Pupation occurs in the larval feeding tunnels close to the surface of the bark or within the frass tubes.

Larvae of E. formosana are a pest of fruit trees in the family Rosaceae. Larval damage results in swellings and cankers, and branches or entire trees may be killed. Larvae have also been recorded on beech (Fagaceae).

Plant Associations

View full screen host table here

Links

Additional photos and a distribution map of this species in North America are available at Moth Photographers Group.