Host Plant Location By Ambrostoma Quadriimpressum And Technique Of Harmless Control

The beetle Ambrostoma quadriimpressum Motschulsky (Coleoptera: Chrysomelidae) is strictly monophagous on elm. For rampant damage of the beetle and disadvantages of chemical control, this paper did research on controlling the beetle by nontoxic sticky glue ring, host plant location, host specificity. The following are the results:1. Study on host specificityIn order to make sure whether host specificity of this beetle is strict, wo conduct this test in the lab and field. Wo have been feeding the beetles by foliage of Ulmus pumila, Salix babylonica, Betula platyphylla, Prunus tomentosa, P. triloba for some days. Finally, we find that they only feed on elm and their host specificity is strict.2. Host plant location by the beetleThe beetles were not more attracted to intact twigs or feeding damaged twigs than black control. The average number of beetles reaching the intact twigs were not significantly defferent from that reaching black control, feeding damaged twigs too.In the field tests, when antennae of the beetles were removed, still they can find and reach their host plant very well. But when their compound eyes were painted by white paint, only few can find their host plant. So vision is important for plant location by the beetle.Results of test show that visual range of the beetle is 3m. If outside this range, they will can't find their host plant. Them prefer adjacent plant.By tests, wo find the beetles prefer red and black to white, blue or yellow, and they prefer deep red and dark, they prefer the models whose diamerter is greater or higher models. Maybe they can't distinguish different shapes, the numbe of the beetles reaching the cylinder, regular triangular prism and regular rectangular prism were not significantly different.3. Controlling the beetle by nontoxic sticky glue ringThis test is preventing A. quadriimpressum climbing up the tree by nontoxic sticky glue ring, and contrasting the control efficiency of sticky glue ring with esticide ring and spraying pesticide. The results show: the control efficiency of sticky glue ring is the best, its mortaligy is above 90%, this mortaligy was remarkable higher than pesticide ring (32.63%) and spraying pesticide (68.90%). Moreover, the efficiency of this method can last long time, it can control the pest in entire spring. By contrast, the best and effictive width is 5cm, whose control efficiency could get 89.57%.