Study On Parasitism And Assessment Of Pest Control Ability About Two Parasitic Wasps On Myzus Persicae

With the rapid development of vegetable cultivation in facilities,the occurrence of greenhouse pests is becoming more and more serious,Myzus persicae has become one of the most serious pests in greenhouse in northern China.Through previous investigations,the results show that Diaeretiella rapae and Aphidius gifuensis are the main parasitic wasps for peach aphid in greenhouse.In order to determine the parasitic responses and developmental fitness of the two native aphidiidaes on M.persicae.Then,evaluate the potential of two aphidiidaes to control the M.persicae.To provide theoretical basis and technical reference for the control of M.persicae in greenhouse by aphidiidae in Jilin area in the future.In this paper,the effects of host age,aphidiidae age and temperature on the parasitic ability of aphidiidaes were investigated.The functional reaction equations of two species of aphidiidaes on M.persicae were calculated,and the life tables of two species of aphidiidaes and M.persicae at 25?were worked out.The following five points are the main results of this paper:1.Parasitic response and developmental fitness of two aphidiidaes on different ages of M.persicaeBy comparing the parasitic responses of two aphidiidaes on different ages of M.persicae.The results show that:Aphidius gifuensis preferentially host in the early stages,The number of parasitic aphids in 1st–3rd instars aphids was significantly higher than 4th instar and adult aphids,and the maximum parasitic amount was 30.2 aphids at the second age stage;Diaeretiella rapae preferentially host in the 2nd and 3rd stages,the parasitic number of these instars was significantly higher than that of other ages,and the maximum parasitic amount was 34.6 aphids at the second age stage.When on the same age host,the number of parasitism of Aphidius gifuensis was significantly higher than Diaeretiella rapae,at 1st instar,and Diaeretiella rapae was significantly higher than Aphidius gifuensis at 2nd and 3rd instars;No significant difference in other ages.Both the developmental period and the emergence rate of the two aphidiidaes in the host were significantly lower with the increase of the host age,the sex ratio of offspring increase with the increase of host age.2.Parasitic response and developmental fitness of two aphidiidaes on M.persicae on the different ages of female waspsComparing with the parasitic response and developmental fitness of two aphidiidaes on M.persicae on the different ages of female wasps under the indoor conditions.The results show that,Under the condition of the same age of two aphidiidaes,The parasitic quantity of Aphidius gifuensis was higher than the Diaeretiella rapae.When the age of the wasp is different,There were significant differences in parasitism between Aphidius gifuensis and Diaeretiella rapa.When the daily age of the wasp was 1-3d,the parasitism of two aphidiidaes was significantly higher than that of 4-5 day old wasps,and the largest parasitic number of two aphidiidaes were the 2 day old female wasps.The number of parasites of Aphidius gifuensis is 44.6,and the number of parasites of Diaeretiella rapa is 39.6.The developmental duration of Aphidiideas on M.persicae were decreased with the increase of the age of wasp.Under the condition of the same age of female wasp,The developmental duration of t Diaeretiella rapa was significantly lower than that of the Aphidius gifuensis.When the age of wasp is different,There was no significant in eclosion rate between the two aphidiidaes.But under the same age of the wasp condition,The emergence rate of Diaeretiella rapa was significantly higher than Aphidius gifuensis.3.Effect of temperature on parasitic response and developmental fitness of two aphidiidaesBy studying the parasitic response and developmental fitness of two aphidiidaes under different temperature conditions,the results show that temperature had a great effect on the parasitic number,developmental period,sex ratio of offspring and emergence rate of the two aphidiidaes.Neither of the two aphidiidaes could parasitize the M.persicae at 35?under indoor conditions;The parasitic numbers of both species showed a tendency of increasing first and then decreasing with the increase of temperature at 15-30?;The parasitic number reaches the maximum at 25?.Under the same temperature conditions,the parasitic number of Diaeretiella rapae was significantly higher than Aphidius gifuensis.At 25?,the developmental period of the two aphidiidaes was significantly lower than other tested ones,and the emergence rate was significantly higher than other tested ones,while the sex ratio of the two species decreased significantly with the increase of temperature.4.Parasitic functional responses of two aphidiideas to M.persicaeThe functional responses of Aphidius gifuensis and Diaeretiella rapae to M.persicae were studied.Under the condition of test,the parasitic number of two Aphidiideas increased with the increase of host density.Their functional responses can well fit the equation of the Holling-?.The instantaneous attack rate of the Diaeretiella rapae is less than that of the Aphidius gifuensis.The theoretical parasitic upper limit of the Diaeretiella rapae and Aphidius gifuensis were 107.37and 91.05.5.The life table evaluate parasitism potential of two Aphidiidae on M.persicaePopulation life tables of M.persicae and two Aphidiideas were compiled under laboratory conditions.The results show that,R₀?r_m??and T of Diaeretiella rapae and Aphidius gifuensi were 124.19,0.48,1.62,11.16 and 179.63,0.40,1.50,12.89.R₀?r_m??and T of M.persicae were 56.28,0.37,1.45 and 1.92.They were obviously greater than the r_m and R₀ of pest.Show that the parasitic ability and had high breeding speed of two strong Aphidiidae on M.persicae.The population growth rate also are better than that of M.persicae.So two kinds of Aphidiidae showed better control potential on M.persicae.By comparing the functional responses of two aphidiidaes on M.persicae and Analysising the Life Table parameters of two aphidiidaes on M.persicae.On the whole,Diaeretiella rapae and Aphidius gifuensis have good parasitic effects on M.persicae.However,Aphidius gifuensis shows better breeding advantage and has a greater application prospect.