麦蚜发生规律及预报研究

STUDIES ON OCCURRENCE AND FORECAST OF THE WHEAT APHIDS

经多年系统观测，关中麦区麦蚜种类为麦长管蚜、麦二叉蚜、禾谷缢蚜、麦无网蚜和玉米蚜。麦长管蚜是小麦生长后期危害优势种；渭北旱塬和关中灌区西部小麦生长前期的优势种分别为麦二叉蚜和禾谷缢蚜。据麦蚜混合种群数量消长规律，提出渭北春季麦蚜混合种群发生量峰值预测式。麦二叉蚜、麦长管蚜在渭北非极端寒冷年份可以成、若蚜安全越冬，未谷缢蚜只部分年份可以越冬。小麦适期晚播可减少黄矮病的发生，但对麦蚜却无控制作用。

The results of investigation and test showed that there are five species of aphids in win-ter wheat fields in Guanzhong,Shaanxi.i.e. English grain aphid Macrosiphum avenae(F.),Greenbug Schizaphis graminum(Rond),Oat bird-cherry aphid Rhopalosiphum padi(L.),Rose grass aphid Acyrthosiphon dirhodum(Walker),and Corn leaf aphid Rhopalosiphummaidis (Fitch).The most prevalent species in late growing period of wheat is English grainaphid,in seedling is greenbug in Weibei is oat bird-cherry aphid in wester Guanzhong area ir-rigated.Peak aphid population has been suggested that a forecast model through dynamic in-vestigation. Based on the comparitive studies of number in late autumn and early spring andthe source analysis of species in early spring,the writers considered that English grain aphidand greenbug may overwinter by adult and nymph in wheat fields except special cold circus-tance and oat bird-cherry aphid only in some of years in Weibei.By late sown wheat can es-cape infested by BYDV but the number of aphids can not be reduced. Finally based occurringregular and regional characteristic the writers suggested that aphids occurring areas inGuanzhong can be divided into 3.