Monitoring Fruit Flies in Litchi Orchards in South Africa and Determining the Presence of Alien Invasive Bactrocera Species

Fruit flies (Diptera: Tephritidae) includes about 4300 species in almost 500 genera. It is amongst the largest families of Diptera and one of the most economically important. The larvae of many species develop in the seed bearing organs of plants. Several species are known to attack commercially grown crops. Losses are due to direct feeding damage by larvae and also due to loss of export markets. Approximately 50 species in Africa are of economic importance. Most species which attack commercially grown fruit crops belong to two genera only, namely Ceratitis and Dacus. A few species belong to other genera such as Trirhithrum and Bactrocera. Bactrocera is a large genus in Asia and Oceania and several species have been introduced to Africa. The invasive fruit fly, Bactrocera invadens poses a great threat for the South African fruit industry. Fruit flies were monitored in litchi orchards in different production areas during the 2011/12 season. The objectives were to identify fruit fly species present and to facilitate early detection of invasive fruit fly species in areas. Yellow bucket traps with three different lures were used i.e., methyl eugenol, Cuelure and three component lure. Bactrocera invadens was not collected from any of the methyl eugenol baited traps. The pumpkin fruit fly, Dacus bivittatus, was a common species collected in the traps with Cuelure. Dacus bivittatus is common and a widespread pest, especially being associated with Cucurbitaceae, and is not a pest of litchi. The Natal fruit fly, Ceratitis rosa was the dominant species collected in traps with three-component lure and is a well-documented pest of litchi. This information is important in formulating an integrated pest management strategy.