SEXUAL RESPONSES OF ADULT MALE AEDES AEGYPTI USING THE FORCED-COPULATION TECHNIQUE

¹ Department of Entomology, University of Maryland, College Park, Maryland 20742

1. Virgin females which are 24 hours old or less interfered with the copulatory attempts of males by kicking with their legs and emitting fluid from their ani. About 50% of these young females could be force-copulated, and 75% of these were inseminated.

2. The mean forced-coital time of young virgin females which were inseminated was 71.4 seconds. Those which were not inseminated force-copulated for a much shorter time (15.6 seconds).

3. The sexual responses of males to young virgin females were not uniform with the forced-copulation technique. Active refusal by withdrawal of the male terminalium from the female by the male was more definite with young females than with older ones.

4. Prolonged coitus was observed in about 8% of the forced-copulations with young virgin females; this phenomenon has not been reported for cage-matings nor has it been seen in nature.

5. Ninety-five of 100 virgin females force-copulated, whereas only one 3-second copulation was obtained with 100 females that had been previously cage-mated.

6. A force-copulation rate of 10% was recorded for females that had force-copulated 12 hours previously.

7. The cerci and the eighth abdominal segment appeared to be more deeply retracted in inseminated females than in virgin females.

8. While individual males varied in their sexual responses toward similar females, 52% of them definitely responded to them and 92% of these individuals copulated.

9. Using the forced-copulation technique, precoital and coital time means were 16.0 and 20.7 seconds, respectively. The age of the male did not influence these values.

10. The number of copulations by 5- and 7-day-old males was significantly higher than that by 1-and 3-day-old males.