果园间作小麦对黑绒鳃金龟寄主选择行为的影响

Effects of Triticum aestivum Intercropping in Orchards on Host Selection of Maladera orientalis

黑绒鳃金龟(Maladera orientalis Motschulsky)是一种多寄主害虫,但是伴随着剧毒农药禁用,已经成为果园的一种重要害虫。由于黑绒鳃金龟昼伏夜出的生物学特性,喷雾防治很难收到好的防治效果。为有效控制果园黑绒鳃金龟,同时达到农药减用的效果。本研究以苹果(Malus pumila)、梨(Pyrus spp.)、桃(Prunus persica)、樱桃(Prunus species)和山楂(Crataegus pinnatifida)为寄主,以小麦(Triticum aestivum)为试材,通过室内选择和田间趋避试验研究了小麦对黑绒鳃金龟选择行为的影响。在果树枝条和小麦之间进行选择时,黑绒鳃金龟对每种果树枝条的选择率都≥90%,而对小麦的选择率都<10%;不同果树枝条与小麦混合放入同一容器后,黑绒鳃金龟对混合物的选择率明显低于对单一果树枝条的选择率;小麦同时存在于H型嗅觉仪两臂时黑绒鳃金龟的选择行为明显受到影响,两臂之间的选择率差异不明显,且黑绒鳃金龟的不选择率最高达到了25%;田间间作试验发现无间作物的樱桃园、梨园、苹果园3种果树上黑绒鳃金龟的虫口数量分别达到了18.4、17.6、18.9头/株。而间作小麦后黑绒鳃金龟的虫口数量明显下降(P<0.05),其中樱桃上黑绒鳃金龟虫口数量最大,仅为4头/株;同时发现间作小麦后3种果树的叶片受害率相对于没有间作物的果园明显降低;距离试验表明,距小麦0.5、2 m的梨树叶片被黑绒鳃金龟为害率分别为8%、9%,差异不明显(P>0.05),而在距小麦6 m时梨树的叶片的受害率上升为35%,明显高于距离0.5 m时(P<0.05),而在距离8 m时梨树叶片的受害率73%,明显高出0.5 m时8倍(P<0.05)。这些结果表明,小麦严重干扰了黑绒鳃金龟的寄主选择行为。在樱桃园、梨园和苹果园间作小麦对黑绒鳃金龟具有较好的趋避防治效果,在间作果园当梨树与小麦距离在2 m以内对黑绒鳃金龟的趋避效果非常明显。

M. orientalis is a polyphagous pest. It is an important pest in the fruit orchards where many highlytoxic pesticides was prohibited. Because of the nocturnal biological characteristics, the M. orientalis could not be controlled by spray contact pesticide. To effectively control the M. orientalis and reduce spraying chemicalpesticides, the effect of T. aestivum on host selection behavior of M. orientalis was studied in door and fieldexperiment by using Malus pumila, Pyrus spp., Prunus persica, Prunus species, Crataegus pinnatifida and T.aestivum as the materials. The results showed that the selection rate of different kinds of fruit branches wasall ≥90% the selection rate of T. aestivum was 10% when the M. orientalis made selection among differentkinds of fruit branches and T. aestivum; the selection rate of the mixture of different kinds of fruit branches andT. aestivum was significantly lower than single kind of fruit branches. When T. aestivum existed both in the twoarms of the H shaped olfactometer, the selection behavior of M. orientalis was disturbed, there was nosignificant difference of the selection rate between the two arms and the highest no selection rate was 25%. Infield experiments, the population of M. orientalis in Prunus species orchard, Pyrus spp. and Malus pumila orchards with intercropping nothing were 18.4, 17.6 and 18.9 per plant, the population of M. orientalis decreased significantly under wheat intercropping in orchard. When the distance of pear to wheat was 0.5 mand 2 m, the percent of injury Pyrus spp. leaves were 8% and 9%, respectively, there was no significantdifference（P0.05）; when the distance was 6 m, the percent of injury Pyrus spp. leaves increased to 35%,which was significantly higher than the 0.5 m（P0.05）; when the distance was 8 m, the percent of injury Pyrusspp. leaves was 73%, which was 8 times higher than the 0.5 m（P0.05）. It was concluded that T. aestivum wasnot the host plant of M. orientalis, T. aestivum could disturb the locating host behavior of M. orientalis. Therewas an excellent avoidance control effect against M. orientalis in Prunus species orchard, Malus pumila andPyrus spp. orchards intercropping T. aestivum. When the distance of Pyrus spp. to T. aestivum was no morethan 2 m, the avoidance control effect against M. orientalis would be excellent.