Larval development of the plantainfeeding moth <i>Scopula rubraria</i> (Doubleday) (Lepidoptera Geometridae)

Abstract

Tonic plantain has become a popular forage crop but several Lepidoptera species not traditionally considered pests have caused significant damage in some stands At least two species of looper caterpillars (Family Geometridae) commonly referred to as plantain moths Scopula rubraria and Epyaxa rosearia have been associated with serious defoliation Both are thought to be New Zealand native species with S rubraria also present in Australia Leafroller caterpillars (Family Tortricidae) Merophyas leucaniana (New Zealand native) and M divulsana (Australian species) have also been found damaging plant crowns Scopula rubraria were collected from a Manawatu plantain/grass sward A laboratory colony was Five larval instars for both sexes were observed; mean weights at the start of each instar were 004 032 164 460 and 995 mg Most larval growth occurred in the fifth instar with mean maximum weight being 3565 mg Mean durations of each instar were 54 48 35 42 and 101 days and the total larval stage was 280 days Pupal duration averaged 118 days Resultant adults began laying eggs 12 days after eclosion and these hatched in 7 days The total length of the life cycle was approximately 49 days