Conditions for increased insemination rates in caged Aedes triseriatus (Diptera: Culicidae) reared from field-collected eggs.

Primarily in order to facilitate future studies on venereal transmission of La Crosse encephalitis virus by Aedes triseriatus, tests were conducted to identify conditions that maximize insemination rates in caged populations of Ae. triseriatus derived from field-collected eggs. All tests were conducted at 21 degrees C +/- 1 degree C, which is approximately the mean temperature during July and August in southwestern Wisconsin where La Crosse virus is endemic. Non-bloodfed females exposed on their 5th through 8th day of adult life showed little sexual receptivity to either 5- to 6-day-old males or 8- to 9-day-old males. F1 females were no more receptive than their mothers had been at a similar age. Mean insemination rates did not exceed 32.6% in any of these age combinations at sex ratios ranging from 4 males: 1 female-1 male: 4 females. Mean insemination rates ranged as high as 89.0% when non-bloodfed females were exposed on their 9th through 12th day of adult life to 5- to 6-day-old males in a 4 male: 1 female ratio. In females given a bloodmeal on their 4th day of life and exposed on their 5th through 8th day to 5- to 6-day-old males, mean insemination rates ranged as high as 91.7% at a ratio of 2 males: 1 female.