Eupoecilia ambiguella (Hübner) (Tortricidae: Tortricinae: Cochylini)
Common names: European grape berry moth (preferred), European grape vine moth, grape berry moth
Synonyms: omphaciella (Tinea), roserana (Tortrix), turbinaris (Clysia)
FWL: 6.0–7.5 mm
The forewing is yellow or yellowish orange with a well-defined dark-brown to black median fascia. Males and females exhibit no sexual dimorphism in wing pattern although females may be slightly larger than males. Males lack a forewing costal fold.
Male genitalia are characterized by a reduced uncus, short socii, prominent transtilla, distally triangular valva, and large phallus. Female genitalia are distinguished by a broad, short ductus bursae and a corpus bursae with numerous sclerotizations and spines.
The following account is summarized from Gilligan and Epstein (2011)Gilligan and Epstein (2011):
Gilligan, T. M., Epstein, M. E.. 2011. The European grape vine moth not found in California: Eupoecilia ambiguella (Hubner)., pp. 32-34. In : Plant Pest Diagnostics Center Annual Report 2010. California Department of Agriculture, Sacaramento, CA..
Mature larvae approximately 10–12 mm in length. Head, prothoracic shield, legs dark brown to black; body color varies from brown to yellow and green; pinacula large, conspicuous, brown; anal shield pale brown.
The following comments are summarized from Gilligan and Epstein (2011)Gilligan and Epstein (2011):
Gilligan, T. M., Epstein, M. E.. 2011. The European grape vine moth not found in California: Eupoecilia ambiguella (Hubner)., pp. 32-34. In : Plant Pest Diagnostics Center Annual Report 2010. California Department of Agriculture, Sacaramento, CA..
Adults may be confused with other species of Eupoecilia or Cochylini, although E. ambiguella is the only cochyline commonly associated with grape. A genitalic dissection can be used to confirm E. ambiguella identity.
Larvae cause damage similar to Lobesia botrana and the two species can be found sympatrically. Other tortricid grape pests include Argyrotaenia franciscana, Argyrotaenia ljungiana, Epiphyas postvittana, Paralobesia viteana, Platynota stultana, and Proeulia spp. Larvae of E. ambiguella can be separated from the larvae of other tortricid grape-feeding pests by the L-group pinaculum on T1, which extends horizontally beneath the spiracle in E. ambiguella.
Eupoecilia ambiguella is widely distributed across the Palearctic, where it is more common in cooler and humid climates. It has been reported from Brazil (EPPO 1997EPPO 1997:
EPPO (European and Mediterranean Plant Protection Organization). 1997. Data sheets on quarantine pests: Acleris variana and Acleris gloverana . https://gd.eppo.int/download/doc/797_ds_ACLRSP_en.pdf [accessed 15 October 2020] (.pdf).), but this record could not be verified. It is not considered established outside of Europe and Asia.
The following account is summarized from Gilligan and Epstein (2011)Gilligan and Epstein (2011):
Gilligan, T. M., Epstein, M. E.. 2011. The European grape vine moth not found in California: Eupoecilia ambiguella (Hubner)., pp. 32-34. In : Plant Pest Diagnostics Center Annual Report 2010. California Department of Agriculture, Sacaramento, CA..
The biology of Eupoecilia ambiguella is similar to that of Lobesia botrana, with the exception that there are two generations per year for E. ambiguella compared to three or more generations per year for L. botrana. Over most of its range, adults are present in May and June for the first generation and again in August and September for the second generation.
Females deposit eggs singly on buds, pedicels, and flowers during the first generation, and on grape berries (Vitis spp.) during the second generation. Early instar larvae burrow into the buds or berries and feed internally; later instars web together buds or berries, and a single larva can feed on up to a dozen berries. Pupation occurs in leaves for the first generation and under bark for the second generation. Overwintering occurs as a second generation pupa. Development time is highly dependent on temperature and humidity. The optimum relative humidity level for development is 70% or higher; eggs will fail to hatch at low relative humidity levels.
Economic losses on grape are caused by direct feeding damage and secondary infections. Larvae of the first generation cause minor damage by feeding on flower buds, while those of the second generation cause the most damage by feeding on grape berries. The most significant losses are due to secondary infection of feeding sites on berries and clusters by Botrytis cinerea fungus. Economic thresholds vary with the type of grape and cultivar.
Although grape (Vitis vinifera) is the most economically important host, E. ambiguella has been recorded from many different plants in several families.
Authors: KA Austin, TM Gilligan, ME Epstein
Content last updated May 2025
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