Cold storage of Culex pipiens in the absence of diapause.

A major expenditure in vector biology laboratories is the rearing of mosquitoes. Most mosquito colonies require substantial effort to maintain, including frequent bloodmeals for optimal performance. Successful cryopreservation of mosquitoes continues to be elusive. Although using diapause as a storage mechanism is an option for mosquito preservation, several obstacles include the lack of a well-characterized diapause or the inability of some species to enter diapause. Thus, other options for preservation are needed. To address this issue, we investigated the use of long-term low-temperature storage in the absence of diapause for adults of the northern house mosquito, Culex pipiens L. Our results indicate that although male longevity is not substantially increased by cold storage, female longevity is dramatically increased by storage at lower temperatures. When mated before storage, females remain reproductively viable after at least 10 wk of storage, although at reduced levels. These results indicate that cold storage without diapause induction is a viable option for colony maintenance in vector biology laboratories.