Cnephasia stephensiana

Status

ADVENTIVE

PORT INTERCEPT | DOMESTIC SURVEY

Taxonomy

Cnephasia stephensiana (Doubleday) (Tortricidae: Tortricinae: Cnephasiini)

Common names: gray tortrix moth, tobacco leaf worm

Synonyms: Too many to list here. See Gilligan et al. (2018)Gilligan et al. (2018):
Gilligan, T. M., Baixeras, J., Brown, J. W. 2018. T@RTS: Online World Catalogue of the Tortricidae (Ver. 4.0). http://www.tortricid.net/catalogue.asp [accessed 8 October 2020]. for a full list.

Adult Recognition

FWL: 8.0–9.5 mm

Head, thorax peppered with black and white scaling, thoracic tuft black; forewing with ground color pale gray to gray, crossed by two jagged, irregular gray-brown or black fasciae; male without forewing costal fold; hindwing gray.

Male genitalia are characterized by slender, horn-like signum; small socii; and long, slender valvae with a simple, well-sclerotized sacculus to two-thirds length of valva. Female genitalia are characterized by large, irregularly-shaped papillae anales; short, robust apophyses; and signum present as an elongate, scobinate patch.

Larval Morphology

The following account is summarized from Meijerman and Ulenberg (2000)Meijerman and Ulenberg (2000):
Meijerman, L., Ulenberg, S. A. 2000. Arthropods of Economic Importance: Eurasian Tortricidae. Arthropods of Economic Importance series. ETI/ZMA..

Mature larva 15–18 mm in length; head variable, from light brown or amber to entirely black; prothoracic shield black, greenish-gray anteriorly; legs black; body pale bluish-green; pinacula black; anal shield brownish black; anal fork absent.

Similar Species

Several other species of Cnephasiini are very similar to Cnephasia stephensiana, such as C. asseclana and Decodes basiplagana. Dissection may often be necessary to differentiate them. Males of C. asseclana have a longer sacculus and females have a shorter ductus bursae compared to C. stephensiana. The valvae of D. basiplagana are much more slender than in C. stephensiana and do not have such a well-sclerotized sacculus. Females of D. basiplagana have a significantly smaller signum than in C. stephensiana.

Distribution

Cnephasia stephensiana is broadly distributed in the Palearctic region, from Great Britain south to Morocco, east to Russia, Tukey, Korea, and Japan. It was introduced to North America where it was first collected in Nova Scotia in 1954 (Mutuura 1982Mutuura 1982:
Mutuura, A. 1982. Cnephasia stephensiana , a species newly recorded from Canada and compared with the previously recorded C. interjectana (Lepidoptera: Tortricidae). Canadian Entomologist. 114: 667-671.). It has since spread throughout northeastern North America and has additionally been reported from British Columbia and Washington.

Biology

The following account is summarized from Meijerman and Ulenberg (2000)Meijerman and Ulenberg (2000):
Meijerman, L., Ulenberg, S. A. 2000. Arthropods of Economic Importance: Eurasian Tortricidae. Arthropods of Economic Importance series. ETI/ZMA..

In Europe, eggs are laid singly or in small clusters in July and August on leaves of the host plant. Larvae hatch 18–21 days later and immediately spin a silken hibernaculum to overwinter. Feeding does not begin until the following April, at first mining leaves before leaving and feeding in shelters of folded or tied leaves. Pupation occurs in June and July within the feeding shelter. Adults eclose about one month later. There is a single generation per year. Phenology appears to be identical in North America.

Larvae are extremely polyphagous and have been recorded feeding on a huge variety of plants. It can be an occasional pest. The table below is not comprehensive.

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.