不同施藥方式對番荔枝冬期果太平洋臀紋粉介殼蟲（Planococcus minor Maskell）防治效果及經濟效益之評估

"Evaluations of the effectiveness and economic benefits of different pesticide-application techniques in controlling a mealybug, Planococcus minor, on the winter crop of sugar apple, Annona squamosa"

"以人工及自走式鼓風噴霧車噴灑藥劑探討番荔枝（Annona squamosa L.）冬期果上太平洋臀紋粉介殼蟲（Planococcus minor Maskell）之防治效果及經濟效益，2005年實驗結果顯示兩處理之果實平均受害面積比率分別為2.1及6.42%，相對於對照組的果實受害面積比，人工施藥之防治率高達93.6%，而機械噴藥防治率則為78.4%，二者差異顯著。調查發現果實上介殼蟲發生蟲數（y）與果實受害面積比率（x）間呈正相關，且其直線迴歸方程式為y＝237.69x-3.59（r＝0.9761, p＜0.05），若依市場上番荔枝果實遭粉介殼蟲為害面積超過30%就毫無商品價值，可換算出此時發生蟲數約達70隻／果。比較對照、人工與機械施藥三處理之防治成本與收益得知，番荔枝之實際收益分別為244,636、467,317及441,779元／公頃，但因人工較機械噴藥處理之總成本高2.87倍，致估算人工施藥每公頃所得淨收益（實際收益-防治成本）為422,817元，還較機械施藥的426,279元少約3500元。因此番荔枝果園仍以機械噴藥為較佳之防治處理方式。為提高傳統式機械施藥的防治效果，2006年增加機械配合人工之改良式機械施藥處理，其對太平洋臀紋粉介殼蟲的防治率（84.1%）雖較人工施藥者（85.7%）略低，但顯著優於機械施藥法（78.7%）。觀察太平洋臀紋粉介殼蟲於番荔枝果園的發生時期、為害習性與試驗所得之防治成本效益，建議最佳防治時期應於每年春季3～4月及秋季9～10月當介殼蟲之若、成蟲開始由番荔枝果樹之根際向上擴散爬行時進行，且採用噴霧車輔以手持式噴霧槍的施藥方式噴灑藥劑，將可獲最高之防治效果。"

"The efficacy and economic benefits of using manual (MA) and mobile fogger (MFA) pesticide-application techniques in the control of a mealybug, Planococcus minor, on the winter crop of sugar apple, Annona squamosa, were evaluated in 2005. The mean fruit injury area after using both methods were 2.1 and 6.42%, respectively. In comparison with the injury area of the non-treated fruit, the control efficacy of MA was as high as 93.6% and significantly higher than that of MFA (78.4%). Based on the number of mealybugs counted (y) and the percentage of fruits area infested (x), the regression equation of y = 237.69x - 3.59 (r＝0.9761, p＜0.05) was calculated. The number of mealybugs on fruit with injury area ＞30% which has no commercial value on market, is about 70/fruit. Based on the various control costs and market values, the actual incomes for treatments of without pesticide application, MA, and MFA were 244,636, 467,317 and 441,779 NTD/ha, respectively. Due to the 2.87-fold costs of MA, the net incomes (actual income - control cost) by using MFA (426,279 NTD/ha) was about 3500 NTD/ha more than that by MA (422,817 NTD/ha). Results of the analysis of their economic benefits showed that the MFA was a better method. In order to improve the control efficacy of MFA, an improved mobile fogger application method (IMFA) of combining MFA and MA, was added in the tests of 2006. The control percent of IMFA (84.1%) was significantly higher than that of MFA (78.7%). Based on our studies on the occurrence of mealybugs, its movement and infestations in the field, and the control costs and benefits of sugar apple production, the best control timing for the mealybugs would be in the spring from March to April and in the fall from September to October, when the nymphs and adults of the mealybugs were crawling upward from the root bases to the fruits. Also, the use of IMFA would be mostly effective in the control of the mealybugs in an orchard."