The effects of storage temperature, food, and humidity on survival and progeny of Neoseiulus bicaudus

Neoseiulus bicaudus Wainstein (Acari: Phytoseiidae) is a beneficial predatory mite to control spider mites. To evaluate the suitable storage conditions of N. bicaudus, the survival of adult females was observed under different combinations of low temperature (3, 6, 9, or 12 degrees C), food (F) or no food (NF), and high (H) or low (L) humidity conditions for 7, 14, 21, 28, and 35 d. Predator mites' longevity and survival time of 50% and 80% individuals (ST50,80) were measured and compared between treatments. After storage, female and male living mites were paired at 26 degrees C. The progeny parameters were evaluated after storage. Results revealed that survival rate decreased as storage temperature decreased. At 3 and 6 degrees C, fewer mites survived after 28 d. At 9 degrees C, similar to 50% of the females survived in the FH treatment after 35 d. At 12 degrees C, >80% survived 7-35 d in the FH treatment. Moreover, longevity and ST50,80 were significantly greater in the FH treatment than in the FL or NFH treatments at 3, 9, and 12 degrees C. The highest longevity (48.6 +/- 3.7 d) and ST50 (51.6 d) occurred at 12 degrees C in the FH treatment. There was no effect on progeny hatching or survival rates when adults were stored at 9 or 12 degrees C for 28 d. At 9 degrees C, the total preadult development time was 4.20-5.25 d. At 12 degrees C, the total development time was 4.87-4.93 d and there was no significant difference between the storage treatment and control group. These results demonstrated that N. bicaudus females can be successfully stored at 9 degrees C for similar to 21 d and 12 degrees C for similar to 28 d with little effect on adult survival or progeny parameters.