Minimum dose of gamma irradiation for quarantine treatment against bactrocera papayae (Drew & Hancock) (Diptera: Tephritidae)

Abstract

Bactrocera papayae is one of the most important fruit flies which is distributed in several countries of Asia and Papua New Guinea, including Indonesia. This fly has been given attention, particularly on the international trade of the agricultural commodities, because it carry a risk of entry and spread pest to free area. A quarantine treatment of gamma irradiation is suggested to alter a common chemical fumigation such as methyl bromide (MB). The objective of this research was to determine a minimum dose of 60Cobalt gamma rays applied on egg and larval stages of this fly that were maintained on the artificial diet in-vitro. There were two kind of treatments. First, egg, first instar larvae, second instar larvae, and third instar larvae were irradiated at six level of doses 0 (control), 25, 50, 75, 100, 125 and 150 Gy. Second, the most tolerant stage of the fly based on first treatment, were irradiated at nine level of doses 10, 20, 40, 60, 80, 100, 120, and 150 Gy including control. Our result showed that the third instar was the most tolerant stage of the fly to irradiation treatment. The minimum quarantine dose of irradiation to eradicate the third instar was 114.76 Gy.