Native
Grapholita interstinctana (Clemens) (Tortricidae: Olethreutinae: Grapholitini)
Common names: clover seed caterpillar, clover head caterpillar
Synonyms: distema (Grapholitha), scitana (Dichrorampha)
FWL: 4.0-6.0 mm
Forewings are dark brown with a single pair of white dorsaldorsal:
upper, to the top, on the back
strigulae per wing and four pairs of white costal strigulaecostal strigulae:
small, usually pale, semirectangular marks along the costa
. The ocellusocellus:
forewing pattern element - an ovoid region anterior to the tornus; adult head - a simple insect "eye" located dorsal to the compound eye
is reduced to a silvery-blue bar. The male lacks a forewing costal foldforewing costal fold:
a flap or fold at the base of the forewing that contains specialized sex scales
. The hindwings are brown with a white fringe.
Male genitalia are characterized a rudimentary uncusuncus:
a sclerotized process which is fused to the posterodorsal margin of tergum IX
and by the valvaevalvae:
plural of "valva"
, which have a straight costal margincostal margin:
see costa
and a V-shaped ventralventral:
lower, to the bottom, on the under side
invagination at the neck. Female genitalia are characterized by laterallateral:
to the side
sclerotizations in the ductus bursaeductus bursae:
a membranous tube connecting the ostium bursae to the corpus bursae
and the absence of signasigna:
plural of "signum"
in the corpus bursaecorpus bursae:
a dilated membranous sac at the anterior end of the bursa copulatrix
.
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 5.0-6.0 mm in length; width of head 0.7-0.8 mm; head yellowish-brown with black pigmentation in ocellar area; prothoracic yellowish-brown with some brownish pigmentation; body pale yellow, legs concolorous; pinaculapinacula:
flattened sclerotized plates on a caterpillar that bear the setae
moderate in size, but concolorous and inconspicuous; anal fork absent; SV group on A1, 2, 7, 8, 9 typically 3:3:1(2):1:1.
Detailed figures of larval chaetotaxychaetotaxy:
the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
are available in MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..
Adults appear similar to many other species of Grapholita. In eastern North America, Grapholita fana is most similar, but the two species are easily distinguished by the larger ocellusocellus:
forewing pattern element - an ovoid region anterior to the tornus; adult head - a simple insect "eye" located dorsal to the compound eye
in G. fana. Genitalia of the two species are different: males of G. fana lack the invagination on the ventralventral:
lower, to the bottom, on the under side
surface of the valve and females possess a pair of short signasigna:
plural of "signum"
.
The following account is summarized from Wehrle (1924)Wehrle (1924):
Wehrle, L. P. 1924. The clover-seed caterpillar. Cornell University Agricultural Experiment Station Bulletin. 428. 34 pp..
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.
In the early part of the 20th century, G. interstinctana was considered a significant pest of clover (Folsom 1909Folsom 1909:
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.). Larvae have also been reported feeding on sunflower (Asteraceae).
Host plant | Host plant family | Reference(s) |
Helianthus sp. | Asteraceae | Gilligan et al. 2008Gilligan et al. 2008: Gilligan, T. M., Wright, D. J., Gibson, L. D. 2008. Olethreutine moths of the midwestern United States, an identification guide. Ohio Biological Survey, Columbus, Ohio. 334 pp. |
Trifolium incarnatum | Fabaceae | MacKay 1959MacKay 1959: MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338. |
Trifolium sp. | Fabaceae | Wehrle 1924Wehrle 1924: Wehrle, L. P. 1924. The clover-seed caterpillar. Cornell University Agricultural Experiment Station Bulletin. 428. 34 pp.; Heinrich 1926Heinrich 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. |
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Grapholita interstinctana is distributed in eastern North America from Maine to Alberta, south to Missouri.