The Research Of Different Wheat Varieties On The Occurrence Dynamics Of Wheat Aphid And The Parasitic Wasps

Wheat aphid belong to Aphididae(Hemiptera), which is the most important pest of wheat. In China, the majority of wheat aphid were Macrosiphum avenae, Rhopalosiphum padi,Schizaphis graminum and Acyrthosiphon dirhodum. Wheat aphids not only influence the yield and quality of wheat, but also spread of wheat virus, and affect the economic benefits of whea seriously. So, it is great significantly to take biological measures to control wheat aphids. In order to excavate the wheat germplasm resources which with high aphid resistance and small influence on wasp, the population dynammics of aphids and parasitic wasp on 50 wheat species on Luoyang academy of agricultural sciences were investigated. It had studied the unitization of resistant varieties combined with protection of natural enemies and evaluated the population dynamics of aphids and parasitic wasp. Altogether all results provide a foundation for optimizing the current aphid resistant germplasm resources. The main results of this research are as follows:Through the statistics and analysis of the population structure of the field aphids, we could known that the main wheat aphids in 2014 were Macrosiphum avenae, Rhopalosiphum padi and Schizaphis graminum. And the damage of Macrosiphum avenae and Rhopalosiphum padi were more important than Schizaphis graminum. The main aphid of the testfield was Macrosiphum avenae which accounted for a proportion over 75% of the total amount of the wheat aphids before the middle of April. Rhopalosiphum padi started massively occurring in late April. It became the advantage aphid species in early May, and the number of it was more over than Macrosiphum avenae since then.As the dynamic analysis of the aphids on different wheat varieties, we can learned that Macrosiphum avenae was very serious in the vegetative growth stage of the wheat. It happened since early April and reached the highest on April 10 th, then greatly reduced after April 22 th. The maximum occurrence was accordance and probably focus on April 4th to 14 th. The damage of Rhopalosiphum padi was not serious in the vegetative growth stage of the wheat and not became a advantage aphid specie before May. It happened since early May and reached the highest on May 12 th, then gradually reduced after May 15 th.The maximum occurrence was accordance and probably focus on May 8th to 15 th.We could reached some conclusions through the identification of aphids resistance on different wheat varieties. The resistance of the Macrosiphum avenae of the 50 wheat species was as follows:the immune varieties was none, the aphid resistant varieties was 29 and the aphid susceptible varieties was 21. Among them 1 wheat variety(zhengmai 9023, with resistant index 0.228)was highly resistant to Macrosiphum avenae and 16 wheat variety(32%) were middle resistant. The wheat varieties which with good resistance to Macrosiphum avenae were zhengmai9023, zhengnong 17,yannong 24 and jimai17,etc. The resistance of the Rhopalosiphum padi of the 50 wheat species was as follows:the immune varieties was none, the aphid resistant varieties was 33 and the aphid susceptible varieties was 17. Among them 16 wheat variety(32%)was highly resistant to Rhopalosiphum padi and 13 wheat variety(26%) were middle resistant. The wheat varieties which with good resistance to Rhopalosiphum padi were ningchun 4, yangmai 21, wanhei 064, haimai 13, zhongmai 13, jinmai990, cunmai 1, zhengnong 17,fengkang 38, linyuan 8, xumai 27, zhoumai 22, neimai 11 and emai 25,etc. Different wheat varieties had different resistance to different aphids. Among them 16 wheat varieties(32%) could resistant to Macrosiphum avenae and Rhopalosiphum padi at the same time, 30 wheat varieties(60%) could resistant to only one kind aphid and the remaining 4 wheat varieties(8%) could not resistant to Macrosiphum avenae and Rhopalosiphum padi at the same time. It showed us that the resistance of the wheat varieties in the textfield was well overall.Also, we had find many enmies of the wheat aphids during the investigatting. The parasitism rate of parasitic wasp on aphids were less and the parasitic activity started late. As the maximum parasitic date of Macrosiphum avenae was from April14 th, the maximum parasitic date of resistance varieties of Rhopalosiphum padi was started earlier than the susceptible varieties. The parasitism rate of Rhopalosiphum padi was higher than Macrosiphum avenae. It may control the occurring of the aphids effectively. At last, the parasitic regularity of different wheat varieties was not obvious.