REPRODUCTIVE-BEHAVIOR OF THE SOUTH-AMERICAN FRUIT-FLY ANASTREPHA-FRATERCULUS (DIPTERA, TEPHRITIDAE) - LABORATORY AND FIELD STUDIES

The mate choice, courtship and oviposition behaviour of laboratory-rea red and field-collected Anastrepha fraterculus (Wied.) were compared. In laboratory cultures in Southampton the duration of male calling act ivity in small leks increased gradually from 1-2h at 5 days old to up to 7h at 10 days. This finding correlates with previous reports on the time at which male salivary glands, which are believed to produce sex pheromone, are fully developed. Wild flies which emerged from infeste d fruits in Brazil began to oviposit on the day they mated, whereas in laboratory flies oviposition began 1 day following the first mating. Both types of fly usually defended their position on a particular frui t throughout the day, and re-mated with either virgin or mated males. There was no significant difference in mating duration. Females did no t copulate before the mean age (+/-SE) of 16.8 +/- 0.9 days. For both types of flies mating initiation occurred in the first 2h of photophas e, with virgin females choosing mainly mated males. The average number of matings in the laboratory was three for females and four for males , and the interval between matings in females was significantly increa sed after the second mating. It is suggested that;the tendency of virg in females to mate with mated males will lead to increased fitness, as males are on average 48 days old at their second mating. The potentia l life span of around 200 days for both sexes would allow adults to br idge the gap between seasonally available fruits in warm-temperate and sub-tropical South America.