杨桃园桔小实蝇的防治指标

为有效控制桔小实蝇的危害,通过田间调查桔小实蝇数量动态和杨桃产量损失,研究了杨桃上桔小实蝇的防治指标。结果表明,杨桃产量损失率与桔小实蝇虫口密度、杨桃被害率之间具有显著相关性;建立了第一收获期至第四收获期桔小实蝇虫口密度、杨桃被害率与杨桃产量损失率回归方程。根据防治指标求解模型,将各回归方程系数和求解防治指标参数代入,得到一年四个收获期里不同产量水平下的桔小实蝇的防治指标。当以桔小实蝇虫口密度作为防治指标时,各收获期的防治指标分别为5.6、14.0、19.3和8.8头/瓶;经济允许密度为10.1、19.5、21.7和10.4头/瓶。当以杨桃被害率作为防治指标时,各收获期的防治指标分别为5.3%、8.9%、6.8%和7.5%;经济允许损失率为15.1%、15.3%、12.0%和9.8%。

Economic thresholds of the oriental fruit fly, Bactrocera dorsalis

In order to control the oriental fruit fly, Bactrocera dorsalis (Hendel), efficaciously, economic thresholds of the oriental fruit fly in carambola orchards were studied. There were significantly correlative among the density of B.dorsalis, damage rate and the loss rate of yield. The more B.dorsalis, the more serious the damage and the yield loss. Four regression equations among the density of this pest, damage rate and the loss rate of yield were established. Four economic thresholds were put forward for carambola in different harvest times according to the densities of B.dorsalis, which were 5.6, 14.0, 19.3 and 8.8 adults per trap, respectively, and the corresponding densities of economic tolerable loss were 10.1, 19.5, 21.7 and 10.4 adults per trap, respectively. Based on the damage rate, the economic thresholds were 5.3%, 8.9%, 6.8% and 7.5%; the corresponding rate of economic tolerable loss were 15.1%, 15.3%, 12.0% and 9.8%, respectively.