Rubidium for marking adults of Culicoides variipennis (Diptera: Ceratopogonidae)

Culicoides variipennis adults were reared from media with nine concentrations of rubidium (Rb) ranging from 0.0 to 1,000 ppm. Rubidium levels were measured using an atomic absorption spectrophotometer. Concentrations of 500 and 1,000 ppm of Rb reduced pupal production, adult emergence, and adult longevity; lower levels of Rb had no noticeable effects. Adult females reared from media containing 15.6 ppm Rb were marked for a period of at least 13 d, and Rb levels were unaffected by a blood meal on day 3. One marked fly was readily detected in a pool of five. This technique should be useful in studying the dispersal behavior of C. variipennis under field conditions.