Efficiency of Spinosad Bait and Fruit Net-bag for Trapping the Oriental Fruit Fly, Bactrocera dorsalis (Hendel), in Two Orchards

比較賜諾殺濃餌劑與果實網袋包，在兩種果園中，對東方果實蠅(Bactrocera dorsalis (Hendel))之誘殺效果，結果顯示在酪梨園每週平均所誘得之雌蟲數，賜諾殺餌劑與果實網袋包處理顯著較噴藥對照區為少，三處理依序分別各為6.7、5.7及10.8隻。賜諾殺處理之果實被害率與被害度皆顯著較網袋包處理為少，而兩者又皆顯著較噴藥對照區為低，三處理之平均被害度分別各為1.2、4.4及7.6%。而依據對照區求得之平均防治率，則賜諾殺餌劑與果實網袋包處理分別為70.7及39.9%。在柳橙園每週平均所誘得之雌蟲數，賜諾殺餌劑、果實網袋包及噴藥處理區分別僅各為2.2、3.3及2.9隻，在統計上差異不顯著，顯示三種處理皆能有效壓制此害蟲族群。而此三處理區調查所得之平均被害率僅分別為0.03、0.03及0.07%，在統計上並無顯著差異，亦即顯示三種處理在果實蠅密度較低之時期皆能有良好的防治效果。由此等試驗結果，對於東方果實蠅之防治將可採用賜諾殺餌劑或果實網袋包或噴施農藥，可依不同果園之不同果實期，由資材成本、人力可行性、防治效果及殘毒安全性等來作決定。 Results displayed the efficiency of two baits for trapping the Oriental fruit fly, Bactrocera dorsalis (Hendel), in two orchards. The average females trapped weekly in the avocado orchard after Spinosad bait, fruit net-bag or chemical treating were 6.7, 5.7 and 10.8, respectively. Both the percentage of fruit damage and degree of fruit infested were significantly less in the Spinosad bait treatment than the fruit net-bag treatment, the two treatments were significantly less than chemical spraying control. The averaged degree of fruit infested after Spinosad bait, fruit net-bag or chemical treating were 1.2, 4.4 and 7.6%, respectively. The calculated control rate against B. dorsalis by Spinosad bait or fruit net-bag treatments were 70.7 and 39.9%, respectively. The average females trapped weekly in the orange orchard after Spinosad bait, fruit net-bag or chemical treating were 2.2, 3.3 and 2.9, respectively. The percentages of fruit damage after Spinosad bait, fruit net-bag or chemical treating were 0.03, 0.03 and 0.07%, respectively. Both results showed excellent control against B. dorsalis in the orange orchard by the three treatments during low population stage. Applicable control measures against B. dorsalis can be selected among these three treatments based on different orchards, fruit stages, labor and material cost, control efficiency and pesticide residue