Adult Recognition
FWL: 4.0-6.0 mm
Forewings are dark brown with a single pair of white dorsal strigulae per wing. Male genitalia are characterized by the valvae, which have a straight costal margin and a V-shaped ventral invagination at the neck.
Adults appear similar to many other species of Grapholita. In eastern North America, Grapholita fana is similar, but the two species are easily distinguished by the larger ocellus in G. fana. Genitalia of the two species are different.
Larval Morphology
Late instar larvae are approximately 5-6 mm in length with a pale abdomen. The head and prothoracic shield are yellowish brown. An anal comb is absent.
Biology
Grapholita interstinctana completes 2-3 generations per year. Adults fly from late May to September.
Larvae feed on seeds in the heads of clover; usually one larva is present per flower head. Overwintering occurs as a mature larva and pupation occurs in the spring.
Host plants
In the early part of the 20th century, G. interstinctana was considered a significant pest of clover. Larvae have also been reported feeding on sunflower (Asteraceae).
| Family | Genus/species | Common name |
| Asteraceae | Helianthus L. | sunflower |
| Fabaceae | Trifolium incarnatum L. | crimson clover |
| Fabaceae | Trifolium L. | clover |
Distribution
Grapholita interstinctana is distributed in eastern North America from Maine to Alberta, south to Missouri.
References
Folsom, J. W. 1909. Clover seed-caterpillar, pp. 133-137. In: The insect pests of clover and alfalfa. University of Illinois Agricultural Experiment Station Bulletin 134.
Gilligan, T. M., D. J. Wright and L. D. Gibson. 2008. Olethreutine moths of the midwestern United States, an identification guide. Ohio Biological Survey, Columbus, Ohio. 334 pp.
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist Supplement 10: 1-338.
Wehrle, L. P. 1924. The clover-seed caterpillar. Cornell University Agricultural Experiment Station Bulletin 428. 34 pp.
