Exposure to Guava Increase Male Sexual Competitiveness in the South American Fruit Fly, Anastrepha fraterculus.

RUIZ, M. J.; OVIEDO, A.; ABRAHAM, S.; MENDOZA, M.; SEGURA, D. F.; KOULOUSSIS, N.; WILLINK, E.; VERA, M. T.

Mazatlan

Congreso; 7th Meeting of the Working group of Fruit Flies of the Western Hemisphere; 2008

Plants can affect the sexual behaviour of phytophagous insects were exposure or consumption may result in an increased male sexual performance. Here we examined the effect of fruit exposure in Anastrepha fraterculus male's sexual competitiveness. Two parameters were evaluated: fruit type and exposure time. Six fruit species were used: grapefruit, lemon, orange, mango, papaya, and guava. In the case of citrus, males had access to the essential oil glands products only. The other fruit were cut in halves to allow access to the pulp. Control males were not exposed to the fruit. To run a test, ten treated males, ten unexposed control males, and ten females were placed in plexiglass cages and the number of couples obtained for each male type was registered. Males exposed to guava had a better sexual performance. On the contrary, in cages with males exposed to lemon or grapefruit, the untreated males performed better. The effect of exposure time was evaluated for guava, lemon and mango. In the case of mango there was no effect of fruit exposure on male competitiveness. In the case of lemon, exposures longer than one day eliminated the detrimental impact of this fruit on sexual performance. Males exposed to guavas showed a better mating performance than non exposed males, this was found for wild and laboratory flies but it was not repeatable for all situations. When we tested if mating advantage depended on physical contact with and possibly ingestion of fruit compounds, or was only due to male exposure to volatiles released by the fruit, it was found that the exposure to the volatiles was sufficient to increase male competitiveness. Results obtained showed that it is possible to enhance Anastrepha fraterculus male's sexual competitiveness by exposing them to guavas and we propose that a-copane, or a similar compound, is involved.