Host Plant Volatiles And Its Synergize Responses Of Sex Pheromone In Holotrichia Parallela

The Holotrichia parallela belongs to Coleoptera,Scarabaeoidea,is the dominant species.Whose larvae grubs damage the crops' underground rhizomes,such as peanu ts,corns,potatoes and so on.The adults eating a large number of ground blades,causing huge economic losses to our agricultural production.The conventional chemical means to control them is not ideal for they harm underground.In recent years,people separate and authenticate the active ingredients of H.parallela sex pheromone,then formulate into sex attractant to control them,having controlled them effectively,when it comes to females,it is unsatisfactory.On the other hand,the cost is huge.Based on the current situation,we mix the host plant volatiles of H.parallela and the sex pheromone in different proportions,explore the proportion which can synergize the sex pheromone,and proving in field experiment,enhance the field application efficiency of the sex attractant.The main results are as follows:1.Choice host plant volatiles which have obvious allure liveness to H.parallela.We have selected the active ingredients of 14 major volatiles from the host plants of H.parallela,peanuts,corns,elms,mulberries and others.To select the chemicals which can lure H.parallela effectively through the EAG and olfactory response.The results show:the reaction data of EAG are higher for female adults to cis-3-hexene acetate and trans-2-hexenyl acetate,as 4.84mV,5.12mV respectively.The data above two samples were higher than the others significantly;similarly for males,the data of trans-2-hexenyl acetate is the highest,is 5.68 mV,higher than the other samples significantly.In the olfactory test,for female,the response rates of cis-3-hexene acetate is the highest as 0.98;for male,the data of trans-2-hexenyl acetate is higher,is 0.96.2.The synergies effect of host plant volatiles to the sex pheromoneThe above experimental results showed:the reaction data of EAG and olfactory test are highest for male and female H.parallela adults to the concentration of 103ng/?l of cis-3-hexene acetate and trans-2-hexenyl acetate.We selected these two samples to mix with the sex pheromone for the ratioes of 1:1,1:3,1:5,1:7,1:9 respectively(the following are abbreviated as mixture),to study the synergistic effect of host plant volatiles to the sex pheromone through the test of EAG and olfactory.The results show:(1)For female,the reaction data of EAG is highest to 1:3 trans-2-hexenyl acetate mixture as 4.38 mV,higher than other mixtures significantly;for male,the reaction data of EAG is highest to 1:5 trans-2-hexenyl acetate mixture as 7.64 mV,higher than other mixtures significantly.(2)For female,the reaction data of olfactory is highest to 1:5 trans-2-hexenyl acetate mixture as 0.96;for male,the reaction data of olfactory is highest to 1:7 trans-2-hexenyl acetate mixture as 0.93,higher than other mixtures significantly.3.Field experimentAll above,we select the concentration of 180ug/ul of trans-2-hexenyl acetate to mix with the sex pheromone of H.parallela for the ratioes of 1:1,1:3,1:5,1:7,1:9,to study the synergistic effect of host plant volatiles to the sex attractant depending on the number of field attracting insects.The results show:for female,the ratio of 1:5 is the most for the number of the field attracting insects is 13.67,the efficiency is 412%;for male,the ratio of 1:3 is the most for 318.67,the efficiency is 175%.We have done the single dose of screening,efficiency test,layer upon layer,one by one and the field experiment to identify the trans-2-hexenyl acetate have obvious synergies to sex pheromone of H.parallela.To provide a strong basis for research the more efficient and sensitive trapping agent.