The Bionomics, Distribution and Host Range of the Light Brown Apple Moth, Epiphyas Postvittana (Walk.) (Tortricidae).

Abstract

E. postvittana is an Australian native, introduced into England, Hawaii, New Caledonia and New Zealand. It is known to feed on 73 plant species (12 recorded here for the first time) belonging to 27 families. The lower threshold for development for all stages was 7.5�C. The mean duration of the egg stage was minimal (5.7 days) at 28�C. No eggs hatched at > 31.3�C; the upper threshold for larval and pupal development was 31-32�C. The total day-degrees for the shortest generation time was 620.5, and for 50% egg-laying (cohort generation) 673.6, which allows 3.5 short generations and 3.25 cohort generations per year in Victoria; this confirms field observations. Fecundity was 0-1492 eggs per female. The heavier a female the longer she lives and the more eggs she lays, but there is considerable variation in these relationships which seems to be associated with larval food and with temperature. Under field conditions, pre-oviposition and oviposition periods were 2-7 and 1-21 days respectively; > 50% and > 80% of the eggs were laid by the sixth and the 10th day after emergence respectively. At constant temperatures of 20 and 25�C, peak oviposition occurred when moths were 2-3 days old; > 50% and > 80% of the eggs were laid by the fourth and the seventh day after emergence respectively. The optimum temperature for development is about 20�C.