Cydia youngana

Status

NATIVE

DOMESTIC SURVEY

Taxonomy

Cydia youngana (Kearfott) (Tortricidae: Olethreutinae: Grapholitini)

Common name: spruce seed moth, spruce cone moth

Note: The North American population previously known as C. strobilella was recently demonstrated to be distinct from the Eurasian population based on pheromone and genetic data (Svensson et al. 2012Svensson et al. 2012:
Svensson, G., Wang, H.-L., Lassance, J.-M., Anderbrant, O., Chen, G.-F., Gregorsson, B., Guertin, C., Harala, E., Jirle, E., Libkas, I., Petko, V., Roques, A., Rosenberg, O., Strong, W., Voolma, K., Ylioja, T., Wang, Y.-J., Zhou, X.-M., Louml;fstedt, C. 2012. Assessment of genetic and pheromonal diversity of the Cydia strobilella species complex (Lepidoptera: Tortricidae). Systematic Entomology. 38(2): 305-315.). The name which applies to the North American taxon is Cydia youngana (Kearfott).

Adult Recognition

FWL: 4.5–7.0 mm

Adults are dark brown with lighter, metallic, transverse markings. Hindwings are brown. Males lack a forewing costal fold.

Male genitalia are characterized by the absence of an uncus and terminally rounded valvae with a moderate constriction at the ventral base of the cucullus and a large basal cavity. Female genitalia are characterized by a well-sclerotized ductus bursae and two small tack-like signa in the corpus bursae.

Larval Morphology

The following account is summarized from Tripp (1954)Tripp (1954):
Tripp, H. A. 1954. Description and habits of the spruce seed-worm ( Laspeyresia youngana (Kft.) (Lepidoptera: Olethreutidae)). Canadian Entomologist. 86: 385-402. and MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..

Mature larva approximately 7–10 mm in length; width of head 0.6–0.8 mm; head yellow-brown with darker lateral pigmentation; prothoracic shield, body, legs, and anal shield pale yellow to white; anal fork absent; SV group on A1, 2, 7, 8, 9 usually 2:2:1:1:1.

Detailed figures of larval chaetotaxy are available in Tripp (1954)Tripp (1954):
Tripp, H. A. 1954. Description and habits of the spruce seed-worm ( Laspeyresia youngana (Kft.) (Lepidoptera: Olethreutidae)). Canadian Entomologist. 86: 385-402. and MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..

Pupa light amber, changing to dark brown or black immediately before eclosion of the adult. Male pupae 3.7 mm in length on average; females 4.5 mm in length on average.

Similar Species

Cydia youngana is similar to C. strobilella from Europe and Asia. For a while, the two species were considered synonymous (Brown and Miller 1983Brown and Miller 1983:
Brown, R. L., Miller W. E. 1983. Valid Names of the Spruce Seed Moth and a Related Cydia Species (Lepidoptera: Tortricidae). Annals of the Entomological Society of America. 76(1): 110-111.). They are now considered separate species based on differences in pheromone composition and DNA sequence data (Svensson et al. 2012Svensson et al. 2012:
Svensson, G., Wang, H.-L., Lassance, J.-M., Anderbrant, O., Chen, G.-F., Gregorsson, B., Guertin, C., Harala, E., Jirle, E., Libkas, I., Petko, V., Roques, A., Rosenberg, O., Strong, W., Voolma, K., Ylioja, T., Wang, Y.-J., Zhou, X.-M., Louml;fstedt, C. 2012. Assessment of genetic and pheromonal diversity of the Cydia strobilella species complex (Lepidoptera: Tortricidae). Systematic Entomology. 38(2): 305-315.). They are best separated by distribution; genitalia and life histories are virtually identical.

Distribution

Cydia youngana is widely distributed across the northern United States and Canada.

Biology

The following account is summarized from Tripp (1954)Tripp (1954):
Tripp, H. A. 1954. Description and habits of the spruce seed-worm ( Laspeyresia youngana (Kft.) (Lepidoptera: Olethreutidae)). Canadian Entomologist. 86: 385-402..

Heinrich (1926)Heinrich (1926):
Heinrich, C. 1926. Revision of the North American moths of the subfamilies Laspeyresiinae and Olethreutinae. Bulletin of the United States National Museum. 132: 1-216. stated that two generations occur per year in North America, but Tripp (1954)Tripp (1954):
Tripp, H. A. 1954. Description and habits of the spruce seed-worm ( Laspeyresia youngana (Kft.) (Lepidoptera: Olethreutidae)). Canadian Entomologist. 86: 385-402. found evidence for only a single generation per year in Ontario. Some larvae may require more than one year to complete development.

Adults eclose in late April to early June depending on latitude. Females lay eggs singly under the scales of young cones. Early instar larvae feed on the scales, later moving to the seeds. Mid- to late instars tunnel inside the cone and form a double, branched mine. Mature larvae overwinter and pupate the following spring in the cone. Each cone may support several larvae.

Larvae are a pest of spruce (Picea spp.) and have been recorded feeding on various other Pinaceae.

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.