Abstract The number of male oriental fruit fly from the 0.02% spinosad bait-treated plot (with 8-fold dilution rate) in an open sapodilla orchard (ca 0.1 ha) without barrier was significantly less, 62.4% comparing to the check plot. The control rates of the last 4 weeks were 72.7-86.4% which indicated a significant attracting and killing effect with the use of spinosad bait. spinosad bait was also applied in a small guava orchard, about the same size as the sapodilla orchard, and the control rate calculated from the last 2 weeks were only 58.5-65.9%. The low control rates might be due to that the treated and check plots were too close and no blockade so that the population in check plot was trapped simultaneously. However, the percentage of fruit damage and the degree of fruit infested were significantly lower in the spinosad bait-treated plot than in the non-used check plot. Also, spinosad bait was used in a larger ponkan orchard (ca 1.7 ha) and its surrounding area (0.3 ha), the average percentage of fruit damage was 0 in the spinosad bait-treated plot that was significantly different from that in the control plot. Summarized from the results of three tests, the spinosad bait had a significant control efficacy for the oriental fruit fly. As the application orchard is small, we can add more sprays on the surrounding area or expand the treated area to trap for the outside fly population which may intrude into the orchard, to ensure a better control.
摘要 在約0.1公頃周邊無阻隔的人心果果園內，施用賜諾殺0.02%濃餌劑處理區誘得之東方果實蠅 (Bactrocera dorsalis (Hendel)) 雄蟲數顯著較少，約為無施用對照區的62.4%，調查期間最後4週之防治率達72.7~86.4%，具明顯誘殺效果。在約與人心果果園同等面積的番石榴園施用賜諾殺餌劑，處理區調查期間最後2週之防治率僅為58.5~65.9%，可能是因處理區與無施用對照區相鄰無阻隔，致使對照區之蟲源亦會同時被誘除，但有施賜諾殺試區之果實被害率及被害度則皆顯著較無施用區為低。另在面積約1.7公頃較大之椪柑園及其周邊 (約0.3公頃) 皆施用之情況下，施用賜諾殺餌劑處理區內果實之平均被害率為0，與無施用對照區有顯著差異。綜合此三種果園試驗結果，賜諾殺餌劑對東方果實蠅具明顯誘殺效果。當施用區較小時，可在周邊加強施藥或擴大施用面積，以阻殺可能侵入果園之外來蟲源，增強防治效果。
| Key words: spinosad bait, attractant, Bactrocera dorsalis, control efficacy | | 關鍵詞: 賜諾殺餌劑、誘引劑、東方果實蠅、防治效果。 |
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