Effects of temperature and photoperiod on the production of sexual morphs of Aphis gossypii (Hemiptera: Aphididae) in Jeju, Korea

This study was conducted to quantify the effects of photoperiod and temperature on the production of sexual morph of A. gossypii. Photoperiod and temperature unequivocally affected the production of sexual morphs of A. gossypii. The transition rate of A. gossypii to sexual morphs was increased with decreasing day lengths. No gynoparae or males were induced in 13 h day length at temperatures between 15 and 24 C. No sexual morphs were observed at temperature above 21 C regardless of the day length. We have provided a predicted percentile curves of sexual morph occurrence in relation to photoperiod and temperature. Using this model, critical day lengths at 50% production rate of sexual morphs were calculated to be 12.34, 12.32 and 12.11 hat 14, 16 and 18 C, respectively. The model output predicted well the first male occurrence in the field. Also, this density curve should be useful to understand population dynamics of holocyclic life cycle of A. gossypii in a changing environment. (C) 2016 Published by Elsevier B.V. on behalf of Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.