Aspila packardi

Status

NATIVE

DOMESTIC SURVEY

Taxonomy

Aspila packardi (Zeller) (Tortricidae: Olethreutinae: Grapholitini)

Common names: cherry fruit worm

Synonyms: pyricolana (Steganoptycha)

Note: Aspila packardi was formerly known as Grapholita packardi until recently (Hu et al. 2023Hu et al. 2023:
Hu, G.-L., Brown, J.W., Heikkilä, M., Aarvik, L., Mutanen, M. 2023. Molecular phylogeny, divergence time, biogeography and trends in host plant usage in the agriculturally important tortricid tribe Grapholitini (Lepidoptera: Tortricidae: Olethreutinae). Cladistics. 39(5): 359-381.). Komai (1999) provides a taxonomic history for the Grapholitini.

Adult Recognition

FWL: 3.5–5.0 mm

Adults range in color from light to dark. Light individuals have silvery striae and darker contrasting fasciae while dark individuals lack a well-defined forewing pattern. Males lack a forewing costal fold but have a conspicuous patch of dark sex scales on the dorsal surface of the hindwing.

Male genitalia are characterized by absence of an uncus and the unconstricted valval neck, which is nearly as wide as the cucullus. Female genitalia are characterized by a triangular ostium and two long, thorn-like signa in the corpus bursae.

Larval Morphology

The following account is summarized from MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..

Mature larva approximately 8–9 mm in length; width of head 0.7–0.8 mm; head yellowish brown with darker mottling; prothoracic and anal shields brown; body pale reddish abdomen with moderately large pinacula; anal fork present with 4-6 teeth; SV group on A1, 2, 7, 8, 9 numbering 3:3:2:2:1 or 3:3:2:2:2.

Detailed figures of larval chaetotaxy are available in MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..

Similar Species

Dark individuals may appear similar to Aspila molesta, but are generally much smaller. In western North America, A. libertina is similar in appearance to dark A. packardi in both forewing pattern and male genitalia, but A. libertina males lack a patch of dark sex scales on the hindwing.

Larvae may appear similar to those of many other species of Aspila, Grapholita and Cydia. Cydia pomonella larvae can be separated from A. packardi by the absence of an anal fork and their larger size. Larvae of A. molesta are similar but generally larger. Larvae of A. packardi and A. prunivora are very similar, although the pinacula on the 8th and 9th abdominal segment are more prominent in A. packardi, and the abdomen of A. prunivora is more reddish, especially in preserved specimens. A key for three species of Aspila is available here with photos of adults and male genitalia.

Distribution

Aspila packardi is widely distributed in eastern North America from Nova Scotia, Ontario, and Wisconsin south to Georgia and eastern Texas. It is also present in the Pacific Northwest (Washington and British Columbia) and possibly other fruit-growing regions of the West.

Biology

The following account is summarized from Weires and Riedel (1991)Weires and Riedel (1991):
Weires, R., Riedel, H. 1991. Other tortricids on pome and stone fruits, North American species, pp. 313-434. In : van der Geest, L. P. S., Evenhuis, H. H. (eds.), Tortricid pests, their biology, natural enemies and control. Elsevier, Amsterdam, The Netherlands..

Aspila packardi completes 2–3 generations per year. Over most of its range, adults are present from May to September.

Females lay eggs singly on terminal shoot leaves. Larvae feed inside the shoots or fruit; Chapman and Lienk (1971)Chapman and Lienk (1971):
Chapman, P. J., Lienk, S. E. 1971. Tortricid fauna of apple in New York (Lepidoptera: Tortricidae); including an account of apple's occurrence in the state, especially as a naturalized plant. Spec. Publ. Geneva, NY: New York State Agricultural Experiment Station. 122 pp. found considerable variation in feeding records suggesting that larvae behave differently on different hosts or that a species complex is involved. Overwintering occurs on the host in a cocoon and pupation occurs the following spring.

Larval damage is characterized by injured fruit, early fruit drop, and/or stunted or dead shoots.

Larvae of A. packardi feed on many common fruit crops in the families Rosaceae and Ericaceae. It is possible that hawthorn (Crataegus) is the native host.

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.