Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2010
Publication Date: 11/1/2010
Citation: Rinehart, J.P., Yocum, G.D., Leopold, R.A., Robich, R.M. 2010. Cold storage of Culex pipiens in the absence of diapause. Journal of Medical Entomology. 47(6):1071-1076.
Interpretive Summary: A major expense of many entomology laboratories, both in terms of time and resources expended, is the maintenance of laboratory cultures of the species of interest. This is especially true for disease vectors such as mosquitoes, which must be regularly fed blood meals to generate subsequent generations. In addition to the operational costs of continuous colony maintenance, there can be biological costs as well, such as a gradual reduction in insect quality. This manuscript explores the possibility of using cold storage to reduce the expense of rearing colonies of the northern house mosquito Culex pipiens. Our data indicates that this species can be stored for up to 2 months as adults, and that the stored females are capable of producing eggs once they have been returned to room temperature. Cold storage does lower the number of eggs produced, but production levels return to normal after two generations. Hence, cold storage is a viable option for laboratories interested in maintaining colonies of this species.
Technical Abstract: A major expenditure in vector biology laboratories is the rearing of mosquitoes. Most mosquito colonies require substantial effort to maintain, including frequent blood meals 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 may 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. 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 prior to storage, stored females are reproductively viable, although at reduced levels, after at least ten weeks of storage. These results indicate that cold storage without diapause induction is a viable option for vector biology laboratories.