LIFE HISTORY OF PLUTELLA PORRECTELLA, A RELATIVE OF THE DIAMONDBACK MOTH, PLUTELLA XYLOSTELLA (LEPIDOPTERA: PLUTELLIDAE)

Abstract Although Plutella porrectella (L.) is similar in appearance to the diamondback moth, P. xylostella (L.), several aspects of its biology are quite different from its more common relative. P. porrectella completed two generations per year and overwintered as an early-instar larva within apical buds of dame's rocket, Hesperis matronalis (L.). Four instars were observed in larvae reared in the laboratory. An average of 30 days was required for completion of one generation at 25 °C. This species does not seem to be an alternative host for parasites of the diamondback moth as only a single parasitic wasp, Itoplectis conquisitor (Say), was reared from 228 larvae collected in the field.