【摘要】 经对清涧枣树的蝉害进行调查认为,蚱蝉是该区枣树主要害虫之一,防治该虫已迫在眉睫。其株虫口密度平均为10.30头,高者达16.6头;株被害率平均为69.92%,最高达88.32%;枝被害率平均为28.17%,重者达49.88%。该虫的发生危害规律是:低海拔重于高海拔,滩地、坝地重于山坡地。据调查测估,清涧县6666.7公顷枣林,每年因遭蚱蝉危害而造成的损失达180多万元。更多还原

【Abstract】 After investigation on the damages caused by Cryptotympana atrata (Homoptera:Cicadidae) to Chinese date in Qingjian County,from where the date is mainly produced,the results are as follows:On average the pest number on per tree was 10.30 and the maximum to 16.60;the infested rate on trees 69.92 percent and the maximum to 88.32 percent;the attacked rate on twigs 28.17 percent and the maximum to 49.88 percent.The damage rules were that the lower elevation,beach and flatland orchards were more serious than the higher elevation and sloping field orchards respectively.By estimate,the damage losses caused by the cicada could be about 1.8 million Rengmingbi Yuan annually within total 6666.7 ha of the date orchards in the County.更多还原