Life Table of Bactrocera zonata (Saunders) (Diptera: Tephritidae) for Sterile Insect Technique (SIT) in Mauritius

Abstract

Fruit flies (Tephritidae) have been reported to be a serious pest worldwide. In Mauritius, the major fruit fly species of economic and quarantine importance in agricultural production are Bactrocera zonata (Saunders), Zeugodacus cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel). In line with the government's policy for sustainable and organic agriculture under the challenge of climate change, the Sterile Insect Technique (SIT) is being investigated as an alternative to chemical control. For successful cost-effective SIT programme island-wide, the production of competitive and sterile individuals for release is a key requirement. The aim of this study was to investigate the life cycle parameters of B. zonata to evaluate the feasibility of optimum mass rearing of this species. It was observed that B. zonata has a pre-oviposition period of 8 days, an oviposition duration of 51 days, the number of eggs per female along the complete oviposition period was 705 eggs and the peak egg hatchability varied from 88.5 to 91.5 %. The study showed that egg collection could be started as from day 13. The findings demonstrated that 5 weeks of egg collection is optimal for a rearing facility of B. zonata and production cages should be discarded on day 41. It was found that B. zonata has a net reproductive rate of 300.04 females and a mean generation time of 28.73 days. Given a positive Ro and a short T, it can be concluded that mass rearing of B. zonata is economically viable. Within a short period a laboratory population of this species for mass rearing can be established.