Remating behavior of wild Anastrepha fraterculus females

ABRAHAM, S.; VERA, M. T.; CLADERA, J. L.; WILLINK, E.

Salvador, Bahia, Brasil

Simposio; 7th International Symposium on Fruit Flies of Economic Importance y 6th Meeting of the Working Group on Fruit Flies of the Western Hemisphere.; 2006

Renewal of mate receptivity in insect females results from the need to maximize their reproductive success. Males exert some control over this behavior by trying to avoid sperm competition. It is expected that more fecund females exhaust their sperm reserves faster than less fecund females and hence search for a new mate. In the present study we analyzed the remating behavior of wild Anastrepha fraterculus females under controlled laboratory conditions to determine how remating was influenced by the age of the female at the time of its first mating, the duration of the first mating, and female fertility and fecundity. Thirty wild females obtained from infested guavas in Tucumán, Argentina, were analyzed. Upon emergence, females were kept in individual flasks with food and water with no access to males. Once they were 11 days old, they were offered two sexually mature virgin males for a period of two hours at dawn. This procedure was repeated every 48 hours. If the female mated, the non-successful male was removed from the flask and the age of the female and the duration of the copulation were recorded. From the time of the first copulation, females were offered an oviposition substrate that was renewed every 48 hours. All eggs were collected and incubated to determine egg hatch. The trial concluded after 30 days with a total of 16 observations. Over the 30 females analyzed, 14 remated (46.7%), 7 ended the experiment without remating (23.3%) and the rest of the females, either died before mating (6.7%) or after the first mating but without remating (23.3%). Five females (16.6%) remated twice and only one female remated three times. The refractory period was 17 ± 2 days with a minimum of 10 days and a maximum of 26 days. Remater females mated for their first time sooner than females that did not remate (0.9 ± 0.5 days vs. 4.3 ± 1.3 days; P = 0.007). First copulations were longer for non-rematers than for females that remated (1:18 ± 0:05 h vs. 1:00 ± 0:04 h; P = 0.017). Non-significant differences for fecundity and fertility were found between rematers and non-rematers females, even when values for non-rematers tended to be lower. Fecundity and fertility soon after remating was similar to the values registered before remating (P > 0.05). We can conclude that Anastrepha fraterculus shows a high remating rate even when the refractory period is long. Females remated before a significant reduction in fecundity or fertility occurs and a second copulation did not increase its reproductive success, although it may at least help to keep them at the same levels. It is necessary to confirm these preliminary results with trials involving more individuals and females from well-establish laboratory strains. Assessing the amount of sperm transferred and its association with copula duration will help determine if this feature, or the secretions of accessory glands modulate female receptivity in this species.