RESUMO
Proprioseiopsis asetus (Chant) (Acari: Phytoseiidae) is a relatively unknown predacious mite with potential as a biological control agent of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Tetranychus urticae Koch (Acari: Tetranychidae). In this study, the developmental rate and other biological parameters of P. asetus were investigated. Development of P. asetus was temperature dependent from 10 to 40 degrees C. Nonlinear models were fitted to development rate (1/time) data from egg to adult and by sex to estimate development times. The model of Sharpe and De Michele (1977) best fits the developmental data. The shortest development time on cattail (Typha latifolia (L.)) pollen occurred at 35 degrees C for all stages except for the egg stage, for which it was longer. The optimum development time at 35 degrees C is above the temperature optimum of most phytoseiid mites. Fecundity increased when P. asetus mated more than once. Males were needed at all times for maximum oviposition, although their consumption was negligible. Oviposition, prey killed (Franklinella occidentalis or T. urticae) and longevity of P. asetus females were recorded in the presence of males. Egg production increased with number of prey killed and P. asetus has the characteristics of successful predators of thrips.
