Effects Of EβF Releasing On The Interactions Among Cabbage Aphids, Adybirds And Ants

Due to the pressure caused by the use of chemical pesticides on environmental pollution, food safetyand human health, it’s inevitable that the biological control will substitute pesticides in the integrated pestmanagement. Insect semiochemicals have been recognized as potential alternative tools for the control ofpest. Among semiochemicals relevant for aphid control, aphid alarm pheromone E-β-farnesene(EβF) isamong the most promising, which interferes with aphid host locating and feeding, and also canattract natural enemies. Geostatistics has been comprehensive applied in the insect ecology,and it can provide a more rational basis in formulating sampling method and pestmanagement strategy, by using geostatistics to analysis the spatial pattern of insectpopulations, population dynamics, develop tendency. Many ants and myrmecophilous aphidshave established mutualistic interactions with each other, ants protect aphid from the naturalenemies as they collect the aphid honeydew; when aphids release alarm pheromones, the tendingants become more aggressive and attack to the predators and parasitoids. In this paper, weused the geostatistics method to analysis the affect of the EβF releasing on cabbage aphidsand ladybirds in the field, and did some primary studies on the influence of EβF releasing onthe interactions of Lasius niger, Harmonia axyridis and Myzus persicae. The main results areas following:1. The cabbage aphids show an aggregated spatial arrangement in the sampling period,both in the EβF released field and the control field. The spatial dependence of the aphids was7.16-29.17m in the control field, and7.84-29.07m in the EβF released field. At the end ofinvestigation, the high-density aggregation area of the aphid appeared in the center of thecontrol field, but not in the EβF released field. The amount and spatial distribution ofladybirds were closely related to those of aphids，and there were also great number ofladybirds appeared around the EβF releaser in the center of the EβF released field, due to theattraction of EβF.2. The40μL EβF and20μL EβF dose show extremely significant attraction on femaleHarmonia axyridis (P<0.01), and the10μL EβF dose had significant attraction on it (P<0.05).10μL EβF dose had significant attraction on Lasius niger (P<0.05),20μL and the above were extremely significant (P<0.01).40μL EβF dose had no significant attraction on Lasius nigerthat lived with EβF releasing for3days.3. There was an extremely significant difference in the number of L. niger entering theMyzus persicae colony after EβF released0-2min and2-4min to that beforereleased(P<0.01), but after EβF releasing by6mins, there was no significant difference in thenumber of L. niger entering the Myzus persicae colony in every2mins. We also found thatthe number of L. niger tended to the M. persicae colony reduced significantly after releasingEβF in the aphid-ant mutualistic for5days.4. The aphid tending ants L. niger reduced the number of aphid M. persicae preyed byfemale H. axyridis significantly (P<0.01). EβF releasing increased the aggressive and attackof the L. niger against H. axyridis, and reduced the number of aphid M. persicae preyed byfemale H. axyridis significantly (P<0.05). But in the aphid-ant mutualistic with EβF releasingfor5days, the aggressive and attack of the L. niger was significantly reduced, and number ofaphid M. persicae preyed by female H. axyridis was significantly higher than that withoutEβF releasing(P<0.05) and with EβF releasing after H. axyridis located the M. persicaecolony(P<0.05).