Effect of Male Accessory Gland Extracts on Female Oviposition and Sexual Receptivity of the Caribbean Fruit Fly (Diptera: Tephritidae)

Abstract

Anastrepha suspensa (Loew) male accessory glands do not appear to possess a sex peptide, a factor that induces oviposition or inhibits mating receptivity. Injection of accessory gland extracts from laboratory-colony males into virgin females stimulated daily deposition of only 4 eggs per female, comparable to injections of whole reproductive tract extract (5 eggs per female) and negative controls (4 to 5 eggs per female). Mated females laid significantly more (10 eggs per female per d). Studies of wild-caught males and females yielded the same information: injection of an accessory gland/testes extract or saline both elicited 8 eggs per female per d whereas normally mated females laid 16 eggs per female per d. Female receptivity to mating following injection of accessory gland or whole reproductive tract extracts was comparable to the negative control group, in which 67% to 83% of treated females remated and 63% to 89% of control females remated. In contrast, only 43% of once-mated (positive control) females remated when placed with males. Once-mated females also took significantly longer to remate after exposure to males (359 min) than females from both treatment (61 to 169 min) and negative control groups (76 to 122 min). The duration of mating was similar among all groups (24 to 37 min). These results suggest that oviposition and receptivity inhibition in A. suspensa are not mediated by male-derived humoral factors.