Silicon occupies an important position in the nutrient requirements of wheat. It has been reported that silicon enhances plant resistance to phytophagous insects. However, only limited research has been carried out on the effects of silicon application to wheat and Sitobion avenae populations. In this study, three silicon fertilizer concentrations were treated for potted wheat seedlings, including 0 g/L, 1 g/L, and 2 g/L of water-soluble silicon fertilizer solution. The effect of silicon application on the developmental period, longevity, reproduction, wing pattern differentiation, and other vital life table parameters of the S. avenae were determined. The cage method and the Petri dish isolated leaf method were used to determine the effect of silicon application on the feeding preference of the winged and wingless aphid. The results showed silicon application had no significant effect on the aphid instar of 1–4; although, 2 g/L silicon fertilizer prolonged the nymph stage and 1 and 2 g/L of silicon application all shortened the adult stage and reduced the longevity and fertility of the aphid. Two instances of silicon application reduced the net reproductive rate (R0), intrinsic rate of increase (rm), and finite rate of increase (λ) of the aphid. A 2 g/L silicon application prolonged the population doubling time (td), significantly reduced the mean generation time (T), and increased the proportion of winged aphids. The results also demonstrated that the selection ratio of winged aphids in wheat leaves treated with 1 g/L and 2 g/L silicon was reduced by 8.61% and 17.88%, respectively. The number of aphids on leaves treated with 2 g/L silicon was significantly reduced at 48 and 72 h of aphids released, and the application of silicon to wheat was detrimental to the feeding preference of S. avenae. Therefore, the application of silicon at 2 g/L to wheat has an inhibitory effect on the life parameters and feeding preference of S. avenae.

利用作物间作和挥发物释放的农田害虫生态调控"推-拉"技术,可以增加田间生物多样性,提高天敌的控害效果,减少农药使用.然而,为了实现害虫防控的农药减施增效目的,不同施药器械施药结合生态调控技术对害虫和天敌种群动态以及作物产量的影响研究较少.本研究采用新型自走式喷雾机和传统手动背负式喷雾器两种施药器械,分别对单作小麦、小麦豌豆间作、小麦豌豆间作+蚜虫报警激素反式-β-法尼烯(EBF),以及小麦豌豆间作+水杨酸甲酯(MeSA)等处理下施用杀虫和杀螨剂,系统调查分析四种处理对小麦产量、小麦蚜虫、红蜘蛛,以及相关天敌发生量的影响.结果显示,自走式喷雾机的施药速度显著高于手动背负式喷雾机.不同施药器械防治小麦害虫可以显著影响小麦的穗粒数和产量.自走式喷雾机施药的间作+MeSA处理的小麦千粒重和产量明显高于其他处理.在单作田中,两种施药器械对荻草谷网蚜和瓢虫平均发生量无显著影响,自走式喷雾机施药处理的禾谷缢管蚜、红蜘蛛和天敌僵蚜的发生量显著降低.自走式喷雾机施药的间作+MeSA田的荻草谷网蚜、禾谷缢管蚜和红蜘蛛的发生量明显低于其他处理,而瓢虫的发生量显著高于其他处理.两种药械施药情况下,间作+MeSA田小麦上僵蚜量均明显高于单作田.两种施药器械施药前,单作和间作+MeSA田红蜘蛛发生量较低;施药后间作+MeSA处理的小麦红蜘蛛密度一直维持比较低的水平;间作+EBF和间作+MeSA的两个处理在喷药后第二次调查才达到红蜘蛛数量低峰,而同期的单作处理红蜘蛛发生数量有明显回升.总之,小麦间作+MeSA处理可以显著增加小麦产量,对于麦田小麦蚜虫和红蜘蛛的防控效果和对天敌的吸引保护效果最好.对麦田喷药效率、对害虫防控效果和增加小麦产量综合评价,自走式喷雾机具有明显优势.然而,需要注意的是对比传统手动喷雾器喷药可能对天敌寄生蜂有更强的非靶标作用.

Climate warming affects crop phenology, physiology and biochemistry in agricultural ecosystems and has cascading effects on the performance and abundance of herbivorous insect pests. In this study, a field-simulated warming experiment was conducted using MSR-2420 infrared radiation lamps to assess its effects on the population size and feeding behavior of Sitobion avenae (Hemiptera: Aphididae). Additionally, the activity of the salicylic acid (SA) and jasmonic acid (JA) pathway-related enzymes and their gene expressions in wheat were recorded. Results revealed the population of S. avenae significantly increased in the warming treatment and significantly prolonged the average duration of the E-1 and E-2 waves of S. avenae. Enzymatic assays showed the activities of phenylalaninammo-nia lyase (PAL) and beta-1,3-glucanase (beta-1,3-GA), involved in the SA pathway, and polyphenol oxidase (PPO), involved in the JA pathway, decreased following exposure to elevated warming whereas the activity of lipoxygenase (LOX), involved in the JA pathway, increased. The expression of PAL, beta-1,3-GA, involved in the SA pathway, and LOX and PPO, involved in the JA pathway, were similar to the changes in enzyme activity. Results indicated that S. avenae population increase was positively correlated with its feeding behavior and fitness, and these were correlated with decreasing wheat resistance through the SA and JA signaling pathways.

为明确土壤施硅对小麦蚜虫的防控效果,本研究在小麦种植前分别配施0(CK)、40、80和120 kg/hm2四个浓度的硅肥,测量施硅后小麦生育期、生物量、叶面积、株高、产量指标以及荻草谷网蚜Sitotbionmiscanthi和禾谷缢管蚜Rhopalosiphumpadi发生量.结果表明,施硅对小麦株高和穗数无显著影响,但80 kg/hm2和120 kg/hm2浓度施硅处理后小麦叶面积分别为1 786.03 mm2和2 033.54 mm2,生物量分别为133.68 g和134.50 g,小麦穗粒数分别为35.61粒和35.92粒,小麦千粒重分别为45.34 g和45.59 g,小麦产量分别为9 684.45 kg/hm2和9 835.05 kg/hm2,均显著高于对照,且小麦成熟期较对照提前3 d;80 kg/hm2和120 kg/hm2浓度施硅处理后禾谷缢管蚜发生量分别为90头和86头,均显著低于对照;40、80和120 kg/hm2浓度施硅处理后荻草谷网蚜发生量分别为128、117和105头,均显著低于对照.因此,田间土壤施硅80 kg/hm2和120 kg/hm2可以明显改善小麦农艺性状,提高小麦产量,并能减少麦蚜发生量.