Abstract

The onion thrips, Thrips tabaci Lindeman,is an important polyphagous pest of vegetables and ornamentals in greenhouses. Neoseiulus californicus(McGregor) is a biological control agent of spider mites that also preys on thrips. Little is known about the biology and life table of N. californicus fed on Thrips tabaci. We evaluated the development, survivorship and life-history parameters of the Boku strain ofN. californicusfeeding on first instar larvae of T. tabaci. Total prey consumption by protonymphs and deutonymphs were 3.85 and 3.50, respectively. Total prey consumption during the adult periodin the Boku strain was 65.1 first instar larvae of T. tabaci. Ninety percent of N. californicuseggs hatched but just over 16% of newly hatched larvae attained maturity at 25°C. Developmental time was 9.00 days with T. tabacias prey. Oviposition rate was 2.42 eggs/ female/ day. The average pre-oviposition, oviposition and post-oviposition periods were 3.54, 22 and 3.91 days, respectively. The low estimated intrinsic rate of natural increase (r_m) of N. californicus(0.041 per day with T. tabaci) was due to high juvenile mortalities.