Adult Recognition
FWL: approx. 10 mm
Forewings are light gray and brown. The distal one-third of the wing is marked with a dark-brown to black subtriangular patch that surrounds the ocellus. Hindwings are grayish brown.
Adults may appear similar to other species of Cydia, including the European Cydia splendana. A dissection can be used to confirm identity.
Larval Morphology
Late instar larvae are whitish with a yellow-brown head and prothoracic shield. Abdominal pinacula are dark and conspicuous.
Other tortricid Castanea pests include Cydia fagiglandana, Cydia glandicolana, Cydia splendana, Fibuloides aestuosa, and Pammene fasciana. Brown and Komai (2008) provide a description and key to larvae of these species. Cydia kurokoi larvae can be distinguished by the following characters: whitish abdomen with darker pinacula; D2 pinacula fused to each other on A9; all three L setae on same pinaculum on A9; distance between V setae on A9 greater than on A8; 25-35 crochets on abdominal prolegs; anal comb absent.
Biology
Cydia kurokoi completes one generation per year. Adults are present in August and September.
Larvae tunnel into and feed inside chestnuts. Overwintering occurs in leaf litter as a late instar.
Host plants
This species is a pest of chestnuts in Japan. Larvae have also been recorded on Quercus.
Family | Genus/species | Common name |
Fagaceae | Castanea crenata Siebold & Zucc. | Japanese chestnut |
Fagaceae | Castanea mollissima Blume | Chinese chestnut |
Fagaceae | Castanea seguinii Dode | Seguin's chestnut |
Fagaceae | Castanea Mill. | chestnut |
Fagaceae | Quercus acutissima Carruth. | sawtooth oak |
Fagaceae | Quercus L. | oak |
Distribution
Cydia kurokoi occurs in China, Korea, and Japan.
References
Brown, J. W. and Komai, F. 2008. Key to larvae of Castanea-feeding Olethreutinae frequently intercepted at U.S. ports-of-entry (Lepidoptera : Tortricidae). Tropical Lepidoptera Research. 18(1): 2-4.
Komai, F. and K. Ishikawa. 1987. Infestation of chestnut fruits in China with two species of the genus Cydia (Lepidoptera, Tortricidae). Japanese Journal of Applied Entomology and Zoology. 31: 55-62. [in Japanese]
Meijerman, L. and S. A. Ulenberg. 2000. Arthropods of Economic Importance: Eurasian Tortricidae. Arthropods of Economic Importance series. ETI/ZMA.