Effect of different constant temperatures on the biological characteristics and life table parameters of Euseius scutalis (Acari: Phytoseiidae) fed on cattail pollen

Development, reproduction, and life table parameters of the predatory mite Euseius scutalis (Athias-Henriot), fed on cattail pollen (Typha latifolia L.), were studied at constant temperatures ranging from 15 to 40 °C under laboratory conditions. The pre-imaginal developmental time of females decreased from 24.75 days at 15 °C to 4.06 days at 35 °C, then increased to 4.13 days at 40 °C. An average of 91.51 degree-days was required for E. scutalis females to complete development above the lower threshold temperature of 10.72 °C. Juvenile mortality rates were 58%, 2%, 8%, 2%, 18%, and 65% at 15, 20, 25, 30, 35, and 40 °C, respectively. Females of E. scutalis oviposited an average of 0.00, 10.48, 18.31, 16.19, 4.21, and 3.13 eggs at 15, 20, 25, 30, 35, and 40 °C, respectively, and had a mean longevity of 16.60, 18.31, 17.97, 9.18, 8.75, and 4.73 days at the respective temperatures. The intrinsic rate of population increase (r) at different temperatures ranged from 0.058 to 0.274, with the highest value recorded at 30 °C. These data indicate that E. scutalis is well adapted to high temperatures above 30 °C and could be a useful biological control agent for spider mites during the summer when such temperatures prevail in southwestern Iran. The results could also be used to develop a population model for E. scutalis under field conditions.