FIRST REPORT OF ESTABLISHMENT OF CALOPHASIA LUNULA HUFN. (LEPEDOPTERA: NOCTUIDAE) ON DALMATIAN TOADFLAX, LINARIA GENISTIFOLIA SSP. DALMATICA (L.) MAIRE AND PETITMENGIN, IN NORTH AMERICA

The Eurasian noctuid, Calophasia lunula Hufn., was introduced into North America to control yellow toadflax, Linaria vulgaris Mill., and Dalmatian toadflax, L. genistifolia ssp. dalmatica (L.) Maire and Petitmengin. Larvae feed on the foliage of both toadflax species, but different strains of the moth appear to prefer either yellow or Dalmatian toadflax (Nowierski 1990). Calophasia lunula was first released against yellow toadflax in five Canadian provinces from 1962 to 1968 (Harris and Carder 1971). The moth has been established on yellow toadflax in Ontario since 1965, where it has defoliated up to 20% of the stems (Harris 1988). However, attempts to establish C. lunula on Dalmatian toadflax in Canada have been unsuccessful (Nowierski 1990). Initial releases of the moth in the United States were made in 1968 against both toadflax species with Ontario stock from yellow toadflax (Nowierski 1990). Since then, multiple releases of C. lunula have been made in six western states, including Montana (Story 1985), but until 1989 no establishment had been recorded on either toadflax species.

Host Specificity of Calophasia lunula (Hufn.) (Lepidoptera: Noctuidae)

This report shows: (1) by starvation tests on representative economic plants that none of them is a suitable host for C. lunula, (2) by feeding tests on plants in the Scrophulariaceae that only plants in the tribe Antirrhineae are potential hosts of the larvae, (3) by feeding tests with plant extracts that plants in the tribe Antirrhineae contain an unidentified feeding stimulant, (4) by preference tests with adults and larvae that, although the moths can be raised with difficulty in the laboratory on snapdragon and other ornamentals in the susceptible tribe, they are unlikely to attack these plants in nature.