彫木蛾在小果油茶植株空間分布、危害枯枝提前剪除及田間藥劑防治效果評估

本研究旨在調查彫木蛾（Casmara patrona Meyrick）在油茶植株危害之空間分布，並進行危害枯枝提前剪除及田間藥劑兩種處理對彫木蛾防治方法的效果評估。結果顯示，彫木蛾危害小果油茶造成枯枝之方位以南方占比30.5％最多；造成枯枝之植株高度以中段（70－140cm）分布頻度51.7％為最高。彫木蛾危害枯枝提前剪除防治效果評估結果顯示，比較於7至8月、翌年2至3月進行枯枝剪除處理及對照未剪除枯枝之結果，翌年7月調查枯枝數，調查15株油茶之平均枯枝數分別為1.3±1.6、0.9±1.4及7.2±4.8枝，換算防治率為84.1％及87.0％。7至8月剪除處理之枯枝平均長度為15.0±4.9cm，翌年2至3月剪除處理枯枝平均長度為85.7±20.0cm，結果顯示，於7至8月提前剪除危害枯枝與翌年2至3月修剪時期方剪除危害枯枝，其田間危害蟲數無顯著差異，但提前剪除危害枯枝可減少枯枝長度。田間藥劑處理對彫木蛾防治效果評估結果顯示，在5至6月成蟲羽化交配期於植株施用85％加保利可濕性粉劑稀釋1,350倍、5.87％賜諾特水懸劑稀釋4,000倍及20％達特南水分散性粒劑稀釋3,000倍處理，施藥後1個月調查危害枝條蟲數，調查12株油茶之平均蟲數分別為6.1±3.5、0.1±0.3及1.1±3.3隻，賜諾特及達特南與對照組未施藥蟲數6.3±3.4隻具顯著差異，換算其防治率分別達98.7％及82.9％。依據試驗結果，建議於每年7至8月將彫木蛾危害枝條進行剪除，可明顯降低枯枝長度，進而減少產量損失；每年5至6月成蟲羽化交配期，噴施藥劑於新芽嫩梢，防除尚未鑽入枝條之初齡幼蟲，可有效防治其危害。

關鍵字

蛀莖性害蟲；物理防治；化學防治

並列摘要

This study investigates the spatial distribution of Casmara patrona in Camellia brevistyla and evaluates the control efficacy from pruning time of damaged branches and the use of insecticides. The results indicated that branches facing the South had a greater incidence of larvae (30.5%). The pest distribution was the greatest in the mid-section (70-140 cm plants, 51.7%) in the damaged zone. Evaluation of the pruning time of damaged branches showed that the average number of larvae between July to August and February to March of the following year and the control group were 1.3±1.6, 0.9±1.4 and 7.2±4.8 larvae per 15 plants, respectively. The control rates (%) were 84.1% and 87.0%. The average pruning length of the branch litter was 15.0±4.9 cm between July to August. If the pruning were delayed from February to March of the following year, then the average length of the branch litter would be 85.7±20.0 cm. Regarding the field insecticides test, the results showed that 85% carbaryl WP 1,350 times dilution, 5.87% spinetoram SC 4,000 times dilution and 20% dinotefuran WG 3,000 times dilution during the adult emergence phase (May to June) were 6.1±3.5, 0.1±0.3 and 1.1±3.3 larvae per 12 plants, respectively. The number of pests in control was 6.3±3.4 pests per 12 plants. There was a significant difference when comparing 5.87% spinetoram SC and 20% dinotefuran WG to the control. The control rate was 98.7% and 82.9%, respectively. According to the outcome of the study, it is recommended that a one-off preventative pruning is recommended for the plants between July to August each year. Early pruning reduces the surface area of plant litter for early-stage pest invasion, which in return lowers the yields loss. Since the adult emergence phase of pests occurs between May to June each year, prevention is achieved by spraying the pesticides on the sprouts and young shoots in the outer ring of the tree crown will kill the larvae before they enter the branch.

並列關鍵字

stem borer pest ； physical control ； chemical control

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