Effect of temperature and photoperiod on diapause induction inErioischia brassicae(Bch.) (Diptera, anthomyiidae) under controlled conditions

Abstract

AbstractExperiments were carried out to determine the optimum temperatures and photoperiods for inducing diapause in the cabbage root fly,Erioischia brassicae(Bch.). The induction of diapause occurred at certain receptive stages between the first and third instars of larval development. When developing larvae were subjected to 20±1°C and a 16-h photoperiod for 7–14 days followed by 13±0·5°C and a 10-h photoperiod for 28–35 days, diapause was induced in 84–97% of the pupae; 88–99% of pupae entered diapause when developing larvae were subjected to 13±0·5°C and a 10-h photoperiod for 28–42 days followed by 20±1°C and a 16-h photoperiod for 11–18 days. Similar results were obtained when developing larvae were subjected to 13±0·5°C (day)/7±0·5°C (night) and a 6-h photoperiod. The fecundity of flies from the diapausing pupae was not adversely affected. Application of these results should enable cabbage root fly to be cultured economically for intermittent use.