Submitted to: Journal of Animal Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/1999
Publication Date: N/A
Citation: Harari, A.R., Brockmann, H.J., Landolt, P.J. 1999. Size assortative mating, male choice, and female choice in the curculionid beetle Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae). Journal of Animal Behavior. 58:1191-1200. Interpretive Summary: Research is being conducted to find new ways to control undesirable insects, without the use of large amounts of insecticides. At the USDA, ARS Center for Medical, Agricultural and Veterinary Entomology laboratory in Gainesville, Florida, scientists are studying the mating behavior of pest insects in order to develop methods to interfere with their reproduction and reduce pest populations. The sugar cane root borer weevil, a major pes of citrus in the state of Florida, exhibits mate-guarding by the male, with the male riding on the female for much of the day following mating. It was determined that this behavior prevents the female from mating with other males and assures paternity for the guarding male when eggs are laid. This information will assist efforts to develop control strategies that interfere with weevil reproduction, such as the use of sterile releases of weevils or chemicals that interfere with sexual and reproductive behaviors. .
Technical Abstract: We tested the hypothesis that prolonged post-copulatory guarding is associated with last male sperm precedence in the sugarcane rootstalk borer weevil, Diaprepes abbreviatus (L.). Male D. abbreviatus exhibited post- copulatory guarding for more than 16 hr. However, bothmales and females were more likely to remate after guarding was interrupted compared to after rtermination of undisturbed prolonged guarding. Mating experiments using normal and sterile (Xray irradiated) males revealed a similar value of last male sperm precedence (P2) for both irradiated and normal males (0.72 and 0.73 respectively). Using these data we calculated the expected gain to a male from prolonged guarding versus a male leaving a female early and seeking out an additional mate, and as expected, guarding results in the higher expected gain. Prolonged postcopulatory guarding observed in this species is associated with last male sperm precedence and may have evolved as a male adaptation to prevent female remating with other males. Because of intense male-male competition in D. abbreviatus, prolonged guarding may also benefit the female by ensuring that her eggs are fertilized by the most competitive male.