间作与MeSA释放对麦长管蚜及其优势天敌的生态效应

为探索小麦-油菜(麦-油)间作田释放水杨酸甲酯(MeSA)对麦长管蚜及其优势天敌时序动态的影响和对麦长管蚜的生态控制效应,于2008年10月至2010年6月在山东农业大学泰安实验站进行田间试验.结果表明:麦-油间作与MeSA协同处理区的麦长管蚜无翅蚜种群数量比对照约提前12 d达到高峰,但峰值显著低于小麦单作区.百株小麦麦长管蚜无翅蚜年平均总量:小麦单作区＞麦-油间作区＞MeSA处理区＞间作和MeSA协同处理区,而且间作和MeSA协同处理区瓢虫总量最高;蚜茧蜂发生高峰期比对照提前约10 d,对小麦灌浆期的蚜虫能起到明显的控制作用.以生物控制指数(BCI)作为定量指标、把瓢虫和蚜茧蜂作为优势控制因子进行分析发现,从小麦抽穗到灌浆期,2种因素协同处理能更有效地抑制麦长管蚜无翅蚜的种群增长.     

小麦互益素对麦长管蚜及其天敌的影响

研究了在田间使用小麦互益素--水杨酸甲酯和6-甲基-5-庚烯-2-酮对麦长管蚜及其主要天敌--异色瓢虫和燕麦蚜茧蜂的影响.结果表明,小麦互益素虽然没有明显改变麦长管蚜的田间种群变动趋势,但显著降低了麦长管蚜的种群数量.使用小麦互益素能够恶化麦长管蚜的生存环境,使有翅蚜数量明显增加.尽管小麦互益素使天敌物种丰富度有所下降,天敌群落多样性和均匀度指数下降,但燕麦蚜茧蜂、异色瓢虫等优势天敌的种群数量不仅没有减少反而有所增加.因此,田间使用小麦互益素对控制麦长管蚜的危害具有重要作用.     

麦长管蚜及其天敌的种群发生和食物网分析

【目的】麦长管蚜Sitobion avenae是我国冬小麦产区的重要害虫,为明确小麦-油菜间作(简称:麦油间作)和小麦-大蒜间作(简称:麦蒜间作)田中麦长管蚜及其天敌的种群发生动态,进而为麦田天敌资源的可持续利用和小麦害虫的生态控制提供依据。【方法】本文研究了不同间作方式下,麦长管蚜及其主要自然天敌的种群发生特点,并尝试采用数量食物网的分析方法,描述和分析了不同营养阶层的互作关系。【结果】在调查期内,麦油间作田和麦蒜间作田中麦长管蚜无翅蚜的种群密度在小麦灌浆期显著低于单作田;麦油间作田中有较高的瓢虫种群密度,而寄生蜂的种群密度在小麦抽穗扬花期显著高于单作田和麦蒜间作田;麦蒜间作田有翅蚜的种群数量显著高于单作田和麦油间作田,而对瓢虫和蚜茧蜂的种群数量变动无明显影响。数量食物网分析表明,除草蛉类和食蚜蝇类外,其他同一种类的天敌类群,对3种间作方式下麦长管蚜的控制贡献率差别不大。【结论】麦油间作和麦蒜间作能够提高麦蚜主要天敌的种群数量,进而控制麦长管蚜的危害。     

小麦间作豌豆对麦长管蚜及其主要天敌种群动态的影响

为探索麦田物种多样性对麦长管蚜Sitobion avenae的生态调控效应,于2007年10月至2008年7月在河北省廊坊市进行田间小区试验,系统调查了豌豆与小麦分别以2∶2,2∶4,2∶6和2∶8比例行间作(分别记作2-2间作、2-4间作、2-6间作和2-8间作)种植模式下麦长管蚜种群数量的时序动态, 同时分析了麦田主要天敌种群数量的时序动态、丰富度、多样性指数及均匀度的变化。结果表明：在麦长管蚜发生高峰期,小麦与豌豆间作麦长管蚜无翅蚜的百株蚜量（平方根转换）极显著低于单作田(P<0.01),其中小麦单作（77.38）>2-2间作（68.62）>2-4间作（68.51）>2-8间作（65.19）>2-6间作（64.94）。尽管不同种植模式下,麦长管蚜主要天敌的动态变化趋势基本一致,但间作处理的优势天敌瓢虫类和蚜茧蜂类均有较高的种群密度,天敌群落的丰富度明显提高,Shannon-Wiener多样性指数增加,但均匀度下降。总之,小麦间作豌豆不仅有效降低了麦长管蚜的种群数量,同时也增加了天敌控制害虫的稳定性和可持续性。     

小麦间作大蒜或油菜对麦长管蚜及其主要天敌种群动态的影响

麦长管蚜是我国冬小麦产区的重要害虫.试验探索了不同间作方式对麦长管蚜及其主要天敌的影响.结果表明,在调查期内,麦-油(油菜)间作田和麦-蒜(大蒜)间作田中麦长管蚜无翅蚜的种群密度多显著低于单作田;麦-油间作田中有较高的瓢虫种群密度和瓢蚜比;5月2日前,麦-油间作田中蚜茧蜂的种群密度高于单作田和麦-蒜间作田;5月5日后,麦-油间作田的僵蚜率和蜂/蚜比也显著高于单作田和麦-蒜间作田;麦-蒜间作田有翅蚜的种群数量较高,但瓢虫和蚜茧蜂的种群数量无明显变化.麦-油间作和麦-蒜间作均能对麦田中麦长管蚜起到较好的控制作用.     

吸虫塔对麦长管蚜迁飞监测的影响因素分析

【目的】为了明确吸虫塔对麦长管蚜Sitobion avenae(Fabricius)迁飞活动监测效果的影响因素。【方法】采用回归分析和通径分析等方法,分析田间麦长管蚜数量与吸虫塔吸捕量的相关性,分析不同气象因素对吸虫塔中麦蚜吸捕数量的影响程度。【结果】结果显示,吸虫塔的有翅蚜吸捕量与田间麦长管蚜种群密度及有翅蚜数量存在显著的相关性,即田间麦长管蚜有翅成蚜数量对吸虫塔的吸捕量具有直接影响,而吸虫塔中麦长管蚜的吸捕量也直接反映田间有翅成蚜及种群动态的实际情况。另外,在廊坊地区,吸虫塔初期监测到的有翅麦长管蚜要比小麦田间发生的早几天。通过对吸虫塔中麦长管蚜有翅成蚜吸捕量与气象因素灰色关联度分析的结果表明,降雨天气对麦长管蚜的迁飞和种群动态具有突出的影响作用,可以造成麦长管蚜有翅成蚜迁入的"突增"和种群的"骤降";同时温度和湿度是两个影响麦长管蚜迁飞的重要因素;在麦长管蚜的迁入初期,温度对其迁飞影响最大;在大风天气,风速也会对麦长管蚜的迁入或飞翔活动产生较大影响。【结论】田间麦长管蚜发生数量与吸虫塔的吸捕量存在正相关;降雨、温度和风速是影响麦长管蚜迁飞活动的主要气象因素。     

影响麦长管蚜体色变化的主导因素

研究麦长管蚜Macrosiphum avenae(Fabricius)体色变化生态主导因素,田间红色麦长管蚜种群对不同抗蚜性寄主的反应和自然条件下,不同体色麦长管蚜的生殖力以及后代种群体色变化情况。结果显示:在实验温度范围内,麦长管蚜种群中红体色蚜虫所占比例随温度升高而增加,在28,29,30,31℃时,红体色蚜虫所占比例分别为6.66%,38.30%,70.60%和65.24%。麦长管蚜体色变化过程中,温度起到重要的作用,而与光周期和寄主营养的关系甚微。红体色麦长管蚜在不同抗蚜性的品种上其种群消长情况存在差异。田间红绿体色麦长管蚜经2代观测,平均蚜量比值分别为9.96和15.85,生殖力差异不显著。在小麦抽穗期到乳熟期红体色麦长管蚜个体比例随着田间条件的改变逐代升高(分别由第1代的17.55%和14.70%增至第2代的29.80%和42.2%)。     

风雨对麦长管蚜自然种群发展的干扰作用

麦长管蚜Macrosiphum avenae (Fabricius)是我国重要的农业害虫,给我国的小麦生产造成严重的威胁.经过2006～2008年的系统观测结果表明,风雨气象因素对麦长管蚜种群发展具有显著的影响作用,是突出的关键制约因子.一次6～7级大风(平均风速10 m/s左右)可以显著压制麦长管蚜种群增长的趋势,其种群数量下降65%;在小麦灌浆期的一次强风天气(极大风速达到18.8 m/s),使种群数量迅速下降,直至小麦成熟期未能恢复其种群密度.一次持续10 h的降雨(日降雨量32.2 mm)导致麦长管蚜种群数量骤降80%,并需要7d才恢复到雨前的种群密度.     

麦长管蚜及蚜茧蜂空间格局的地学统计学研究

应用地学统计学的原理和方法研究了不同时期麦长管蚜及蚜茧蜂种群的空间结构和空间相关性,结果表明,不同时期麦长管蚜种群的半变异函数曲线皆为球型,其空间格局为聚集型,变程在33－57cm之间;蚜茧蜂种群的拟合半变异函数曲线也表现为球型,呈聚集空间格局,空间变程在36－55cm之间,并与麦长管蚜种群在数量和空间上有较强的追随关系,说明蚜茧蜂种群是麦长管蚜种群的优势种天敌。     

我国小麦抗麦长管蚜(Sitobion avenae)研究概况

麦长管蚜是我国小麦的重要害虫之一。选育和种植抗虫品种是防治麦长管蚜的理想方法。本文就我国小麦抗麦长管蚜种质资源筛选、抗性机制和小麦品种对麦蚜种群动态影响等方面的研究进展进行了概括,同时指出今后应加强小麦抗麦长管蚜基因的研究。     

Impact of wheat-mung bean intercropping on English grain aphid (Hemiptera: Aphididae) populations and its natural enemy

The effects of intercropping wheat, Triticum aestivum L., with mung bean, Vigna radiate L., on the populations of English grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae), and its natural enemies were evaluated by field and laboratory experiments. The population densities of aphids and their natural enemies were evaluated in the intercropped field against different row ratio combinations of wheat-mung bean. Results showed that wheat-mung bean intercropping caused a drop in aphid densities, and the ratio 12 wheat: 4 mung bean brought about the largest drop (> 8%). In addition, the population densities of coccinellids (ladybirds) and parasitoids and the species diversity of all the natural enemies of aphid were higher in the intercropped field than in the field planted only with wheat. However, intercropping did not influence the community indices (evenness and index of dominance concentration) of the natural enemies. Y-tube olfactometer bioassays were carried out in the laboratory to test whether odor blends of host and nonhost plants affect the host selection of S. avenae. Bioassays indicated that both apterous and alate aphids significantly preferred host plant odor over odor blends of host and intercropped species. Hence, the olfactory-based host location of aphids in the field might be affected by intercropping. The intercropping experiment clearly showed that increased crop species diversity suppresses aphid population growth and preserves the population of natural enemies of aphids. Our results also provide support for the "resource concentration hypothesis" and the "enemies hypothesis".     

麦长管蚜和禾谷缢管蚜对小麦挥发物的触角电位反应

采用活体蚜虫测定法,利用EAG技术比较分析了麦长管蚜Sitobion avenae和禾谷缢管蚜Rhopalosiphum padi有翅及无翅成蚜对小麦挥发物及麦蚜取食诱导挥发物组分的嗅觉反应,揭示了两种麦蚜的嗅觉变异特点。结果表明：麦长管蚜对水杨酸甲酯、反-2-己烯醛、反-2-己烯醇、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2醇的反应较强,禾谷缢管蚜对水杨酸甲酯、反-3-己烯乙酸酯、-6-甲基-5-庚烯-2-酮和-6-甲基-5-庚烯-2-醇的反应较强,并得到了剂量反应曲线。麦长管蚜的有翅和无翅成蚜对6-甲基-5-庚烯-2-酮、反-2-己烯醇和水杨酸甲酯的反应差异显著;禾谷缢管蚜的有翅和无翅成蚜对反-2-己烯醇、辛醛、里那醇、水杨酸甲酯和反-3-己烯乙酸酯的EAG反应差异显著,其原因与禾谷缢管蚜迁移及转主为害的生物学特性有关。     

Methyl salicylate attracts natural enemies and reduces populations of soybean aphids (Hemiptera: Aphididae) in soybean agroecosystems

Methyl salicylate, an herbivore-induced plant volatile, has been shown to attract natural enemies and affect herbivore behavior. In this study, methyl salicylate was examined for its attractiveness to natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and for its direct effects on soybean aphid population growth rates. Methyl salicylate lures were deployed in plots within organic soybean [Glycine max (L.) Merr.] fields. Sticky card traps adjacent to and 1.5 m from the lure measured the relative abundance of natural enemies, and soybean aphid populations were monitored within treated and untreated plots. In addition, exclusion cage studies were conducted to determine methyl salicylate's effect on soybean aphid population growth rates in the absence of natural enemies. Significantly greater numbers of syrphid flies (Diptera: Syrphidae) and green lacewings (Neuroptera: Chrysopidae) were caught on traps adjacent to the methyl salicylate lure, but no differences in abundance were found at traps 1.5 m from the lure. Furthermore, abundance of soybean aphids was significantly lower in methyl salicylate-treated plots. In exclusion cage studies, soybean aphid numbers were significantly reduced on treated soybean plants when all plants were open to natural enemies. When plants were caged, however, soybean aphid numbers and population growth rates did not differ between treated and untreated plants suggesting no effect of methyl salicylate on soybean aphid reproduction and implicating the role of natural enemies in depressing aphid populations. Although aphid populations were reduced locally around methyl salicylate lures, larger scale studies are needed to assess the technology at the whole-field scale.     

麦长管蚜和禾谷缢管蚜对小麦植株挥发物及蚜害诱导挥发物的行为反应

用四臂嗅觉计测定了麦长管蚜Macrosiphum avenae和禾谷缢管蚜Rhopalosiphum padi对小麦植株挥发物及麦蚜取食诱导挥发物的行为反应,揭示了2种麦蚜的嗅觉及小麦植株的诱导防御反应特点.在所选的13种小麦植株挥发物及蚜害诱导挥发物组分中,6-甲基-5-庚烯-2-酮、6-甲基-5-庚烯-2-醇和水杨酸甲酯对这2种蚜虫表现出强的驱拒作用;反-2-己烯醛对麦长管蚜的有翅和无翅蚜的吸引作用最强;反-2-己烯醇对禾谷缢管蚜的无翅蚜吸引作用最强,反-3-己酰醋酸酯对禾谷缢管蚜有翅蚜的吸引作用最强.说明麦蚜取食能诱导小麦植株的防御反应,麦长管蚜和禾谷缢管蚜及其不同蚜型间嗅觉反应的特点不同.     

Assessment of cotton aphids, Aphis gossypii, and their natural enemies on aphid-resistant and aphid-susceptible wheat varieties in a wheat–cotton relay intercropping system

The cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae), is an important cotton pest in northern China, especially in the seedling stage of cotton. After large scale commercial use of transgenic Bt cotton, cotton aphids became one of the most important cotton pests. A 2‐year study was conducted to evaluate the role of four winter wheat varieties that were resistant or susceptible to wheat aphid, Sitobion avenae Fabricius (Homoptera: Aphididae), in conserving arthropod natural enemies and suppressing cotton aphids in a wheat–cotton relay intercropping system in northern China. The results indicated that wheat–cotton intercropping preserved and augmented natural enemies more than a monoculture of cotton. The density of natural enemies in cotton was significantly different among relay‐intercropping fields with different wheat varieties. The highest density of natural enemies and low cotton aphid populations were found in the treatment of cotton in relay intercropped with the wheat variety Lovrin10, which is susceptible to wheat aphid. The lowest density of predators and parasitoids associated with high cotton aphid populations were found with the wheat variety KOK1679, which is resistant to wheat aphid. The results showed that wheat varieties that are susceptible or moderately resistant to wheat aphid might reduce cotton aphids more effectively than an aphid‐resistant variety in the intercropping system by enhancing predators to suppress cotton aphids during the cotton seedling stage.     

植物篱对小麦蚜虫及其天敌种群的影响

采用坡地种植蓑草、苜蓿、香根草和紫穗槐等植物篱的方法,研究了其对小麦蚜虫及其天敌种群的影响.结果表明： 在20°坡度试验区,紫穗槐植物篱显著抑制了麦蚜种群的发生,且麦田拟寄生物的密度等于或显著低于香根草区.在12°坡度试验区,苜蓿和蓑草推迟了麦蚜种群发生的高峰期,蓑草作为植物篱可以显著抑制麦蚜种群数量;苜蓿区麦田拟寄生物密度显著高于对照,瓢虫种群密度等于或显著高于蓑草区.蓑草挥发物对麦长管蚜和禾谷缢管蚜均有驱避作用,而显著引诱猫蛛科1种蜘蛛;苜蓿挥发物对麦长管蚜具有引诱作用;苜蓿和蓑草挥发物对瓢虫的行为反应均无明显影响.紫穗槐和蓑草作为坡地植物篱,不仅能防护水土流失,而且有助于调控害虫及其天敌种群.     

小麦不同品种上麦蚜及其天敌的数量变动

试验结果表明小麦品种 (系 )的抗性对麦蚜种群数量影响很大 ,百株蚜量随着小麦品种抗性增强而下降。而同一小麦品种对不同种蚜虫的抗性存在质的差异 ,铭贤 1 69品种 ,蚜高峰期百株蚜量麦长管蚜 63 0头 ,禾谷缢管蚜只有 1 1 5头 ,两者相差 5 5倍。另一方面 ,小麦品种抗性对麦田天敌的种群数量影响不大 ,而对天敌的发生期有些影响。因此 ,小麦品种抗性、天敌对麦蚜的自然控制能力 ,可把小麦中后期的蚜虫虫口密度控制在经济损失允许水平之下。