黄胸蓟马对香蕉的危害及其防治

１９９６～１９９７年在香蕉花期调查结果表明，黄胸蓟马在广州地区香蕉园中普遍存在，香蕉花感虫率达１００％，平均每花苞感虫８２．８头。感虫数与花苞着生高度有关，以高度１２０～１４０ｃｍ的花苞感虫数最高，以后随高度的增加剧减。黄胸蓟马只危害稍开和已开的第１至第４苞片内花段，且虫口数由外向里递减。园中杂草有助于蓟马对香蕉花的危害，平均每花苞虫口数多杂草蕉园比管理精细的无杂草园多３．６倍。室内药效试验结果表明，毒死蜱、乐果、丁基克百威和灭多威对黄胸蓟马有很好的毒杀效果，氯氰菊酯和顺式氯氰菊酯效果不理想。

Damage of Thrips hawaiiensis (Morgan) to banana and its control.

The damage of Thrips hawaiiensis (Morgan) to banana was investigated for the first time in Mainland China. The results obtained in the period of bunch emergence (flowering) showed that T. hawaiiensis was widely occurred in banana orchards in Guangzhou Region. The infestation rate of flowers (cultivar Guangdong No. 2) was 100% with an average density of 82.8 insect per flower. The insect density was much higher on flowers located 120～140cm above ground than that on flowers located higher. The thrips only infested the first to fourth sepals which were slightly or completely opened and the numbers of thrips were decreased from the first sepal (outside) to the fourth sepal (inside). It was also found out that weeds availed the establishment of thrips population on banana flowers. Thrips decreased significantly in orchads with few weeds compared with that in orchards with many weeds. The efficacy of six insecticides was tested under laboratory conditions. Chlorpyrifos, dimethoate, carbosulfan and methomyl showed highly effective, whereas cyrermethrin and alphacypermethrin were low toxic against this pest.