世界麦双尾蚜研究进展:分布、危害和生物学特性

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has become a worldwide cereal pest with its dispersion to over 30 countries in this century. According to the natural history of its occurrence around the world, it is postulated RWA originated from western or central Asia. The aphid dispersed gradually to Europe and northern Africa, but its big jump across the ocean to North America is still a mystery. There are two overwintering strategies in RWA. The anholocyclic biotype, often reproducing earlier and more offsprings than the holocyclic one, has greater impact on crops in South Africa and United States. According to the experiments on its thermal response, RWA could withstand temperatures below -20℃, while temperatures above 30℃ would be harmful to its survival. The preference to colder condition may determine its distribution on the world. RWA has made great damages to cereal crops worldwide. It caused loss in crop yield by directly feeding on plant nutrition and disturbing the plant metabolism. But its status as plant virus transporter is open to question. By now, the aphid is still a serious pest in many countries and its invasion to more countries and areas maybe continues. Therefore, the research on its biological characteristics as well as its dispersion apparently needs to be enhanced in the future.

麦双尾蚜及其天敌在春小麦和野生寄主上的种群动态

在塔城麦田调查发现， 麦双尾蚜Ｄｉｕｒａｐｈｉｓ ｎｏｘｉａ （ Ｍｏｒｄｖｉｌｋｏ） 在春小麦和野生寄主上的百株蚜量从大到小依次为春小麦、黑麦和野燕麦， 在春小麦上最早出现高峰期。在春小麦上， 瓢虫类数量最多达到５１６ 头／ 百株， 菜蚜茧蜂Ｄｉａｅｒｅｔｉｅｌｌａ ｒａｐａｅ 和白足蚜小蜂Ａｐｈｅｌｉｎｕｓ ａｌｂｉｐｏｄｕｓ 的最高寄生率分别达到３１－６ ％ 和１２－９％ 。在黑麦上， 麦双尾蚜主要被白足蚜小蜂寄生， 最高寄生率达到４２－９ ％ ， 斑腹蝇幼虫Ｌｅｕｃｏｐｉｓａｎｎｕｌｉｐｅｓ 最高达到１６ 头／ 百株。在野燕麦上， 白足蚜小蜂和菜蚜茧蜂最高寄生率分别达到６２－３ ％ 和３１－８ ％ 。瓢虫和菜蚜茧蜂发生较早， 白足蚜小蜂和斑腹蝇发生时间相对较晚。

麦双尾蚜与麦田中生物和非生物因子的灰色关联分析

利用灰色系统理论， 将麦双尾蚜Ｄｉｕｒａｐｈｉｓ ｎｏｘｉａ （ Ｍｏｒｄｖｉｌｋｏ） 种群消长动态与麦田生物群落中主要生物因子和非生物因子进行灰色关联分析。结果表明影响麦双尾蚜及其它麦蚜种群消长的关键因子主要为麦蚜间的竞争和天敌的捕食压力。非生物因子的作用较小， 其中较重要的因子有平均相对湿度和降水量。在塔城小麦田中关键天敌类群为瓢虫类， 寄生天敌的影响较小； 在伊犁小麦田中， 麦双尾蚜及其它麦蚜的关键天敌类群为蚜小蜂类， 大麦田中斑腹蝇类较重要， 燕麦田中瓢虫类占优势。

麦双尾蚜自然种群的特定时间生命表

根据新疆伊犁、塔城两地小麦田调查资料， 组建了麦双尾蚜Ｄｉｕｒａｐｈｉｓ ｎｏｘｉａ （ Ｍｏｒｄｖｉｌｋｏ）自然种群特定时间生命表。由生命表分析得知， 小麦早期生长发育阶段， 麦双尾蚜迁移造成的种群数量损失很小， 反映了麦双尾蚜在早期种群密度较低， 个体对食物和空间资源的竞争压力较小。寄生性天敌在小麦田出现较晚， 在两地小麦早期生长阶段， 由寄生造成的种群损失也极低。整个麦类作物生长阶段， 捕食天敌对麦双尾蚜种群的控制作用非常重要， 是麦双尾蚜种群损失的关键因子之一。迁移造成的种群损失比寄生性天敌的还要大， 说明迁移是麦双尾蚜种群自我调节的重要手段。

四种天敌对麦双尾蚜的功能反应

一种蚜小蜂Ａｐｈｅｌｉｎｕｓｓｐ ． 对麦双尾蚜Ｄｉｕｒａｐｈｉｓ ｎｏｘｉａ （Ｍｏｒｄｖｉｌｋｏ） 的功能反应为ＨｏｌｌｉｎｇＩ型， 直线方程为Ｎａ ＝ ０－６０６０Ｎ－ ３－４７００ 。七星瓢虫Ｃｏｃｃｉｎｅｌｌａ ｓｅｐｔｅｍｐｕｎｃｔａｔａ Ｌ． 成虫对麦双尾蚜功能反应也为Ｉ型， 直线方程为Ｎａ ＝ ０－６０２０Ｎ＋ ５－９０００ ； 多异瓢虫Ｈｉｐｐｏｄａｍｉａ ｖａｒｉｅｇａｔａ Ｇｏｅｚｅ成虫和斑腹蝇Ｌｅｕｃｏｐｉｓａｎｎｕｌｉｐｅｓ Ｚｅｔｔ．３ 龄幼虫对麦双尾蚜的功能反应均为ＩＩ型， 关系式分别为１／ Ｎａ ＝ １－２５５０／ Ｎ＋ ０－００４６ 和１／ Ｎａ ＝ １－３２８０／ Ｎ＋ ０－００７１。

麦双尾蚜及其天敌在不同海拔高度的分布

在新疆塔城， 麦双尾蚜Ｄｉｕｒａｐｈｉｓ ｎｏｘｉａ （ Ｍｏｒｄｖｉｌｋｏ） 在春麦田最集中分布于海拔６００ ～８００ ｍ 高度， 在冬麦田最集中分布于７００ ～８００ ｍ 高度； 冬麦田和同海拔高度的春麦田麦双尾蚜数量密切相关（ｒ＝ ０－９１ ， Ｐ＜ ０－０１） 。麦双尾蚜寄生性天敌蚜茧蜂类和蚜小蜂类， 在春麦田最集中分布的高度为５００ ～６００ ｍ ， 随着时间的延后， 分布的高度范围逐渐扩展； 冬麦田最集中分布的高度为６００ ～８００ ｍ ， 略高于春小麦田。捕食麦双尾蚜的斑腹蝇幼虫在春麦田前期最集中分布的高度为５００ ｍ 处， 后期分布高度上升； 冬麦田较集中分布的高度为６００ ～８００ ｍ ， 也随着时间的延后也上升。

天敌对新疆麦双尾蚜的控制作用

在新疆塔城和哈密春麦田， 用笼罩法研究的结果表明， ７ 月份天敌因素对麦双尾蚜Ｄｉｕｒａｐｈｉｓｎｏｘｉａ （Ｍｏｒｄｖｉｌｋｏ） 自然种群具有明显的控制作用。在试验观察期间， 当部分自然种群出现负增长时， 笼罩的麦双尾蚜增长了４－４～８－３ 倍。塔城春麦田天敌数量变化和麦双尾蚜增长率的相关性分析表明， １９９４ 年蚜小蜂Ａｐｈｅｌｉｎｕｓ ａｌｂｉｐｏｄｕｓ 和斑腹蝇Ｌｅｕｃｏｐｉｓ ａｎｎｕｌｉｐｅｓ 等天敌的控制能力明显，１９９６ 年捕食性的蜘蛛类、瓢虫类天敌作用较强。不同年份天敌优势种类和数量存在明显差异。

世界麦双尾蚜研究进展:防治方法和策略

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), was a worldwide cereal pest. The control measures to this pest were reviewed, emphasizing on natural enemies and plant resistance. First, spring wheat with earlier planting dates had higher yield and could resist RWA infestation to a more extent, while winter wheat with later planting dates could escape infestation of Russian wheat aphid with very few exceptions. So, manipulation of wheat planting dates was suggested in worldwide scale for the aphid control. Second, the natural enemies were considered as the most important factor to reduced the pest status. Introduced and native natural enemies were evaluated for their potential as biological agents in South Africa, United States, and Australia. In South Africa, an introduced parasitoid and a predator were selected for releasing. In the United States, the project on exploring and releasing the natural enemies was unprecedented in biological control history. The endeavor in USA has been proved primarily successful today and will be afterward. The RWA control in Chile was considered most successful, partly because of their introduction of natural enemies before the aphid arrival. The native enemies together with other factors in central Asia and Europe apparently suppressed the aphids to a low level. The screen for resistant wheat was another important research project in fighting with RWA. In South Africa and USA, resistant wheat and barley were bred, and some of them had been put in commercial use for RWA control. The overwhelming mechanisms in resistant wheat varieties were antibiosis, tolerance or their combination. Though chemical insecticide spraying was proved as an effective method for aphid control, more and more research has switched from this method to non chemical control measures as required by IPM. Future research should put more emphasis on augmentation of the natural enemies, revealing the relationship between RWA and agricultural ecosystem and integration of all effective measures.