THE SUITABILITY OF NINE SPECIES OF CRUCIFERAE AS HOSTS FOR THE LARVAE OF THE RED TURNIP BEETLE, ENTOMOSCELIS AMERICANA (COLEOPTERA: CHRYSOMELIDAE)

Abstract

AbstractThe suitability of nine species of Cruciferae as hosts for the larvae of the red turnip beetle, Entomoscelis americana Brown, was tested in the laboratory using excised cotyledons or true leaves as food and rape (Brassica campestris L.) as the standard. The three types of commercial mustards grown in Canada (yellow-seeded (oriental mustard) and brown-seeded (brown mustard) forms of Brassica juncea (L.) Czern.; and yellow mustard, B. hirta Moench) and three weeds (Capsella bursa-pastoris (L.) Medic, shepherd’s purse; Erucastrum gallicum (Willd.) O.E. Schulz, dog mustard; and Sinapis arvensis L., wild mustard) were suitable food plants. Brassica nigra (L.) Koch (black mustard), Descurainia sophia (L.) Webb (flixweed), and Sisymbrium loeselii L. (tall hedge mustard) were marginally suitable. Thlaspi arvense L. (stinkweed) was a non-host plant. These observations suggest that an important element of the pest management system for the red turnip beetle should be the elimination of volunteer commercial mustards and the cruciferous weeds, except T. arvense, in April and May to prevent population build-up.