Bioecology of Alabama Argillacea I. Biology at different temperatures on cotton cultivar IAC-17

Abstract

This research was carried out in order to study the biology of Alabama argillacea Hübner (1818) (Lepidoptera, Noctuidae) at constant temperatures of 20, 25, 30 and 35°C. This study was conducted in climatic chambers under relative humidity of 60 ± 10% and 14 hour photoperiod. Cotton-leaves of the cultivar IAC-17 were used as natural diet. A shortening of the larval period was observed as temperature increased from the 20 to 30°C. There was a variation between the number of instars of the cotton leafworm, and the temperature. There was no correlation between the number of instars and the size of the larvae. The pupal period decreased as temperature increased in the 20 - 30°C range. The optimum for oviposition ranged from 25 to 30°C and there was no oviposition at 20°C and 35°C. A complete life cycle was 26.88 and 17.83 days respectively at 25 - 30°C (optimum range for development). Regression equations for the different phases of the life cycle of the cotton leafworm in relation to temperature were determined.