| Neoseiulus barkeri Hughes belongs to the family Phytoseiidae of Amblyseius.According to the preliminary study,Neoseiulus barkeri Hughes has certain control ability to Scirtothrips dorsalis Hood on mango.Under the conditions of 27±1℃ and RH75%±5%in the room.The predation ability of different insect states of Neoseiulus barkeri Hughes on Scirtothrips dorsalis Hood was analyzed and evaluated by the instantaneous attack rate(a),handing time(Th),predation capacity(a/Th)and other parameters.Under the condition of indoor temperature of 27±1℃ and RH75%±5%,the population life table of Neoseiulus barkeri H ughes feeding on Scirtothrips dorsalis Hood was studied to determine whether Neoseiulus barkeri Hughes feeding on Scirtothrips dorsalis Hood could normally complete its life cycle.Through the control variable method,the temperature,humidity and light intensity were controlled to study the amount of diffusivity of Neoseiulus barkeri Hughes in 24 hours under different conditions,and to evaluate the influence of different conditions on Neoseiulus barkeri Hughes.Hanging bag,hanging bottle and spreading were adopted in the field,and the advantages and disadvantages of the three release methods were compared by investigating the control effect and the number of population in the field.In meishan,ledong and danzhou,1500,3000 and 4500 per tree hanging bags were released and treated with pesticide:1.Study on functional response of Neoseiulus barkeri Hughes to Scirtothrips dorsalis Hood of mango:The results showed that the Neoseiulus barkeri Hughes could feed on the adults,the nymphs of the first and second age of Scirtothrips dorsalis Hood,and had a good predating ability.With the increase of prey density,the daily feeding amount of predatory mites increased gradually.Among them,the female adult mite and the deutonymph mite had the largest predation capacity to the nymph of the first age of Scirtothrips dorsalis Hood(10.35 and 12.82/d,respectively),while the male adult mite had the largest predation capacity to the nymph of the second age of Scirtothrips dorsalis Hood(12.48/d).The female and male adult mites of Neoseiulus barkeri Hughes showed the strongest instantaneous attack rate to the 2-year nymph of the Scirtothrips dorsalis Hood(1.0227 and 1.1208,respectively),while the deutonymph mite showed the maximum instantaneous attack rate to the female adults of the Scirtothrips dorsalis Hood(1.5774).2.Study on the life table of the population of Neoseiulus barkeri Hughes feeding on Scirtothrips dorsalis Hood of mango tea.The results showed that the generation period of the Neoseiulus barkeri Hughes feeding on Scirtothrips dorsalis Hood was 7.91 d.Among them,deutonymph period is the longest for 3.42 d,accounting for 43.24%of the generation period,Larva period is the shortest for 0.70 d,accounting for 8.85%of the generation period.The average number of eggs is 37.00 per female spawning,the survival rate of all generation is 73.33%,the net reproductive rate R0 is 26.9474,the mean generation time T is 15.7406 d,the intrinsic rate of increase rm is 0.2093,the finite increase rate λ is 1.2328,the population doubling time t is 3.3117d,the population trend index/is 20.82.Based on the above results,it can be concluded that the Neoseiulus barkeri Hughes can complete its generation growth,development and reproduction with the Scirtothrips dorsalis Hood of mango as the food.Therefore,it can be considered as an effective natural enemy of the Scirtothrips dorsalis Hood and applied to the biological control of the Scirtothrips dorsalis Hood in the field.3.Effects of light intensity,temperature and humidity on the diffusion rate of the Neoseiulus barkeri Hughes:when the indoor temperature and humidity were 27±1℃ and 60%±5%,respectively,the diffusion rate of the Neoseiulus barkeri Hughes first increased and then decreased with the enhancement of light intensity,and then showed an upward trend.Under the condition of complete darkness,the minimum outward diffusion amount of the Neoseiulus barkeri Hughes was 144.44.Later,as the light intensity increased,the maximum outward diffusion amount reached 1211.11 when the light intensity reached 500lx,and then gradually decreased to 633.33 when the light intensity reached 1500lx.Under the conditions of indoor light intensity and humidity of 300lx and 80%±5%respectively,the outward diffusion quantity of the Neoseiulus barkeri Hughes increased with the increase of temperature,reaching the maximum value at about 25℃,and then gradually decreased with the continuous rise of temperature,reaching the low value of 144.44 at 34℃.When the indoor light intensity and temperature were 300lx and 27℃,respectively,and the humidity was 40%-95%RH,the activity capacity of the Neoseiulus barkeri Hughes showed a rising trend with the increase of humidity,and the overall rising curve showed an "S" shaped curve.At 40%RH,144.44 individuals diffused from the bag,and at 95%RH,1511.11 individuals diffused from the bag.This indicates that the acarids spread out the fastest when the light intensity,temperature and humidity were 500lx,25℃ and 95%RH,respectively.Therefore,the above data could be considered for release in the field.4.Effects of different release modes on field population and control effect of the Neoseiulus barkeri Hughes:among the three release modes of hanging bags,hanging bottles and spraying in the field,there was no significant difference between the release modes of hanging bags and hanging bottles.Among them,on the 21th day,the protective effect of the release mode of hanging bag and hanging bottle reached the maximum value,which was 71.38%and 56.03%,respectively.And the control effect of spraying was significantly lower than that of the other two release modes.The best defense effect was 47.69%on 35th day after release.In terms of field population establishment,there was no significant difference in field population establishment among the three release modes,showing that the population increased rapidly at the initial stage of release,followed by a downward trend and then a dynamic equilibrium.Therefore,hanging bags and hanging bottles should be preferred among the three release modes.5.Neoseiulus barkeri Hughes to field control effect of Scirtothrips dorsalis Hood on mango:organic orchard in Meishan region release different density Neoseiulus barkeri Hughes,the survey found that 1500,3000,4500,the release of the three dimension mode on the control effect is not very significant difference.In the later period,they all tend to be 10.00%.But on the construction of the Neoseiulus barkeri Hughes field populations,4500 density of population is always the most,1500 density of Neoseiulus barkeri Hughes was least populations;Ordinary orchard in Ledong and Danzhou release Neoseiulus barkeri Hughes,Ledong area to hang the processing of leaf density of 3000 and 4500 control effect overall better than the other treatment.At 49d,it reached 74.87%and 57.40%,respectively.And compared the use of chemical pesticide control effect is particularly significant.Danzhou area density the best treatment effect in 4500.The maximum protective effect was 78.21%at 21 d,is superior to other groups of processing,and overall is always better than the treatment group and the control effect of applying pesticide,and release both Neoseiulus barkeri Hughes population is always in the field of the density of 4500 release Neoseiulus barkeri Hughes population most,least 1500 release density populations.To sum up,as the natural enemy of controlling Scirtothrips dorsalis Hood in mango fields,the Neoseiulus barkeri Hughes can be released in organic orchards with a density of 1500,and in ordinary orchards with a density of 4500,so as to achieve better control effect and save cost.Overall,Neoseiulus barkeri Hughes as natural enemies of the Scirtothrips dorsalis Hood on mango,has good control effect,and can complete the Neoseiulus barkeri Hughes of life cycle,for Scirtothrips dorsalis Hood in the field of prevention and control has a relatively good control effect.In the field,hang bag and hang bottle has better control effect,in different orchards adjust measures to local conditions,take the release of different density can achieve good economic benefit and control effect. |
PDF Full Text Request