Abstract
This study investigated the effect of photoperiod and temperature on the bionomics of the three Thrips tabaci lineages (L1 and L2 – leek-associated, and T – tobacco-associated). The experiment was performed in the laboratory under the following conditions: 23 °C 16L/8D and 8L/16D, and 15 °C under 8L/16D. Reproductive diapause was detected in the T lineage at 23 °C and 8L/16D, but not in the L1 and L2 lineages, while all three lineages diapaused at 15 °C and 8L/16D. Adult longevity of L1, L2, and T lineages were 29.51, 25.69, and 29.76, respectively, at 23 °C under 16L/8D; 30.9, 28.52, and 38.06, respectively, at 23 °C under 8L/16D; and 48.9, 34.22, and 76.89 days, respectively, at 15 °C. Mean fecundity of L1, L2, and T lineages were 89.30, 80.31, 86.76, respectively, at 23 °C under 16L/8D; 40.14, 46.94, and 39.34, respectively, at 23 °C under 8L/16D; and 7.0, 13.85, and 17.87, respectively, at 15 °C. The difference in responses to photoperiod and temperature could be a factor to cause a sympatric population variation of the different T. tabaci lineages under the same environmental condition.