Effect of long-term cold storage of the predatory mite Neoseiulus californicus at high relative humidity on post-storage biological traits

The present study investigated whether long-term cold storage at high relative humidity (RH) affected the quality of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) in terms of its survival and reproduction. For this purpose, we examined biological traits at the end of storage and during the post-storage period. Mated females three days after adult emergence were stored individually in 1.5-ml vials for 15, 30, 45, 60, or 75 days at 5.0 +/- A 0.3A degrees C and RH of 99 +/- A 0.1% under continuous darkness. At the end of the storage period, 94-100% of females had survived when the storage period was a parts per thousand currency sign30 days, but percent survival decreased with longer storage. After storage, female survival and oviposition rates were equivalent to un-stored females at 24 +/- A 1A degrees C, RH of 93 +/- A 2%, and a photoperiod of LD 16:8 h. The quality of progeny (hatchability, survival to adulthood, and sex ratio) of stored females was not affected by storage periods as long as 60 days. These results indicate that storage using the tested method can preserve N. californicus for at least 30 days without any degradation.