GAINESVILLE -- In a new hypothesis for a behavior observed in a number of species, two researchers say the process of natural selection may explain homosexual behavior in a beetle that preys on citrus in South Florida.
An article about the research co-authored by an Israeli researcher and a University of Florida professor is scheduled to appear in the Oct. 21 edition of the journal Nature.
Ally R. Harari, a researcher at the Volcani Center at Ben-Gurion University in Israel, and Jane Brockmann, professor and chair of UF's department of zoology, studied the behavior of Diaprepes abbreviatus, an inch-long black beetle commonly known as the sugar cane rootstalk borer weevil. The research began in 1996 at UF when Harari was a post-doctoral researcher in UF's department of entomology.
Both male and female beetles mount each other, Brockmann said. When she and Harari studied the females' behavior in laboratory experiments, they discovered the sight of a pair of mounted females attracts large males, who are equally likely to mate with either of the two females. Small males, by contrast, stay away, apparently dissuaded by the size of the top female.
"We are hypothesizing that by mounting each other, the females are able to attract more attention from larger males than if they were seeking males alone," Brockmann said, adding that bottom females are capable of pushing top ones off but do not do so.
Homosexual behavior is observed in a number of insects and other animal species, Brockmann said. The standard explanation for the behavior in domesticated animals such as cows is that mounting is a display of dominance, she said. The beetle's behavior, by contrast, appears to suggest a different explanation.
"By mounting other females, females are improving their reproductive
success because they are able to mate with larger males," Brockmann said.
"Larger males are advantageous because their large size m
Contact: Aaron Hoover
University of Florida