Flea Beetles and Mustard Oils: Host Plant Specificity of Phyllotreta cruciferae and P. striolata Adults (Coleoptera: Chrysomelidae)1

Abstract
Insect samples from field plots of plants representing 23 different families indicated that adults of the flea beetle Phyllotreta cruciferae (Goeze) and the striped flea beetle, P. striolata (F.), have a narrow host range, restricted among the plants tested to the families Capparidaceae, Cruciferae, and Tropaeolaceae. This result was confirmed for P. cruciferae adults by laboratory feeding preference tests; of 55 plant species belonging to 31 families, only those plants belonging to the families Capparidaceae, Cruciferae, Tropaeolaceae, and Limnanthaceae were eaten. The coincidence between the preferred plant families and the plant families known to contain mustard oils suggested that these compounds or their glycosides might be acting as chemical attractants for the beetles. Field experiments showed that allyl isothiocyanate is a powerful attractant for adults of both P. cruciferae and P. striolata.
Keywords