Effects of cold storage on field and laboratory performance of Trichogramma carverae (Hymenoptera: Trichogrammatidae) and the response of three Trichogramma spp. (T. carverae, T. nr. brassicae, and T. funiculatum) to cold

Abstract

Delaying emergence of Trichogramma spp. is critical for commercial production. Here, diapause induction was considered for three species (Trichogramma nr. brassicae Bezdenko, Trichogramma carverae Oatman & Pinto, and Trichogramma funiculatum Carver), and the effect of storage temperature (4°C, 8°C, and 10°C) and time (1-8 wk) was investigated for T. carverae. For all species, percentage of emergence was lowered after an initial diapause induction period (28 d at 14°C and a photoperiod of 8:16 [L:D] h) and lowered further after 1-mo storage at 3°C and a photoperiod of 0:24 (L:D) h. No wasps emerged after 2 mo of storage, suggesting that true diapause was not induced. The effect of 1-8-wk stor..