Study of the response to heat of Queensland fruit fly in mangoes allows additional varieties to be exported to Japan

Abstract

'Kensington' mangoes have been exported to Japan following a vapour heat treatment (VHT) developed against Queensland fruit fly and Mediterranean fruit fly and which was subsequently verified against Bactrocera papayae. To build on this initial market access activity, four other mango varieties with potential for export to Japan were identified. These were 'R2E2', 'Kent', 'Palmer' and 'Keitt'. However, the Japanese quarantine authorities required that the VHT disinfestation treatment already in use for the variety 'Kensington' be proven equally effective in eliminating fruit flies in these other varieties. Therefore research was undertaken at the Agency for Food and Fibre Sciences disinfestation laboratory of the Department of Primary Industries (DPI) in Brisbane, Australia. Fruit fly-infested mangoes of each additional variety were treated simultaneously with the variety 'Kensington'. The fruit were heated to core temperatures of 41°C through to 47°C followed by immediate cooling. These comparative studies, conducted against Queensland fruit fly, showed that there was no significant difference in the heat response of eggs treated in the variety 'Kensington' and eggs treated in either 'R2E2', 'Kent' or 'Keitt' mangoes. Queensland fruit fly eggs were significantly less tolerant when treated in 'Palmer' mangoes. On the basis of these results, the existing vapour heat treatment of 47°C + 15 minutes, developed to allow export of 'Kensington' mangoes to Japan, is accepted as being equally effective against fruit flies in these four additional varieties. This research provided essential entomological data leading to the approval to export mangoes of the varieties 'R2E2', 'Kent', 'Palmer' and 'Keitt' to Japan.