| According to the Xinjiang Ostrinia furnacalis is not clear,its natural resources is composed of dominant natural enemies control status of insect pests is not clear,the corn borer to major maize producing areas in southern and Northern Xinjiang(Ostrinia furnacalis)were systematically investigated natural parasitization of overwintering larvae and egg field,has been investigated in our region parasitoids on corn borer pest control ability.In addition,through the systematic study of corn field arthropod animal community structure,ascertaining the composition of Xinjiang corn borer predators field resources,the kind of dominant natural enemies northern spring maize planting area,and combined with the indoor predation has clear advantages for the largest predatory natural enemies on the 1-3 egg masses and corn borer larvae predation system,find out the corn borer pests in Xinjiang corn producing areas of corn and its dominant natural enemies of pest control ability,provide a scientific basis for promoting the sustainable development of green agriculture is the mining and use of local protection and control of natural enemies,the corn borer.The main conclusions are as follows:1.The species of the spring sowing maize arthropod community in northern Xinjiang were abundant.After systematic investigation,11628 arthropods were obtained,belonging to 3 classes,13 orders,42 families,66 genera,66 genera,71 species.The corn borer Ostrinia furnacalis(Hubern)and Zygina salina Mit were the dominant species in this area.The dominant species of natural enemies were Hippodamia Variegata(Goeze)and Propiylaea quatuordecimpunctata Linnaeus,Neoscone doenitzi(Boes.et Str.),Chrysopa Sinica Tjeder and Hippodamia tredecimpunctata Linnaeus.The study on arthropod community of spring sowing maize field in different sowing dates showed that the delay of sowing time had little influence on the occurrence of natural enemies and neutral insects,but the amount and damage rate of the insect larvae of corn borer in the flourishing period showed a significant decreasing trend with the delay of sowing date.The structure characteristic index of arthropod community in spring sowing corn field was similar to that of the total community.The large occurrence of the dominant species of corn borer and three spot leafhopper of corn caused significant changes in the characteristic index of arthropod community in maize field,which was the main factor for the stability of the affected community.The principal component analysis showed that the dominant factors affecting the changes of arthropod community structure in the maize field were the number of species of predatory arthropod species,the number of individuals and the number of phytophagous arthropods.Exploring the arthropod community structure is an important way to find out the composition of predatory natural enemies resources of spring corn field in northern Xinjiang.2.Through the discovery of 8 Xinjiang corn borer populations of overwintering larvae: the investigation of parasitic natural enemies are Lydella grisescens and corn borer semiclausum,pathogenic bacteria are mainly Beauveria bassiana,bacteria and virus type.Which kind of bacteria and viruses in various regions have occurred and the infection rate was as high as 57.24%,followed by Beauveria bassiana,regional infection rate is low,but Urumqi can reach 25.80%;parasitic natural enemies inclass,Lydella grisescens only occurred in corn borer in northern and Eastern Hami,including Yili,bole,parasitic rate is higher,can be reached more than 21.99%,but only in the north of Yili and new Urumqi,and the parasitic rate of less than 1%.Therefore,it is of great significance to use the natural pathogenic bacteria and the mailing fly of the corn borer to control the wintering base of the corn borer and control it.In addition,we also in 2017 the South and the north of Xinjiang 3 prefectures and 5 counties of the egg field natural parasitic condition were systematically investigated.The results showed that the two generation egg region above the natural parasitic rate can be as high as 92.78%,its main parasitoids were trichogrammachilonis,trichogrammadendrolimi and Diablo Trichogramma(local bee species),thus,parasitoids of corn borer pest control ability.According to the grey system analysis of the quantitative relationship between predominant predators and dominant pests in the northern Xinjiang corn field,it was found that the variation of the population of the dominant species of the natural enemy,Pallus ladybird,grass flies and the new yellow brown arachnoid population,was the highest in the population of the dominant species of corn borer and three point leaf leafhopper,which showed that the number of dominant natural enemies and the main pest population changed.It has a remarkable following effect.3.Based on analyzing the community structure of arthropod animal on the predation ability of c.sinica,spotted Ladybug and tawny spider Park respectively and controlled evaluation,and the results showed that:the benefits of each age ostriniafurnacalis functional response of 3 dominant natural enemies belong to the Holling-type,namely natural enemies and predation ability the density of prey to negative acceleration curve.The control capacity of the strongest lacewing larvae of Ostrinia furnacalis,the 1 age,2 age,3 age ostriniafurnacalis 24 h maximum predation rate were 353.32,53.98,17.42 head head head,and predation on the eggs of 24 h maximum weight of 251.03 seed predation.Therefore,the protection and utilization of corn field dominant predators,to control the occurrence and damage of corn borer has important significance. |
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