阿维菌素和哒螨灵亚致死剂量对土耳其斯坦叶螨实验种群生命表的影响

为了了解阿维菌素和哒螨灵对土耳其斯坦叶螨Tetranychus turkestani Ugarov et Nikolski实验种群的亚致死效应, 为新疆土耳其斯坦叶螨的综合防治提供理论依据, 我们在室内通过叶碟饲养的方法, 利用生命表技术研究了阿维菌素和哒螨灵亚致死剂量对土耳其斯坦叶螨实验种群成螨和卵的影响。结果表明: 阿维菌素和哒螨灵LC₂₀、LC₁₀剂量处理成螨后, 可使成螨的产卵量、平均寿命和卵孵化率显著降低; 卵期、幼螨期、若螨期和产卵前期明显延长, 而成螨期和雌螨寿命又明显低于对照; 对次代种群的影响表现在净生殖率(R₀)、 周限增长率(λ)降低、生存率和平均每雌日产卵率明显降低, 内禀增长率（r_m）由0.37降低至0.17～0.29, 平均世代历期(T)除阿维菌素LC₂₀处理时长于对照外, 其他处理均低于对照, 种群倍增时间(Dt)延长。两种药剂亚致死剂量处理卵后, 内禀增长率（r_m）由0.32降低至0.11～0.22, 净生殖率(R₀)降低, 平均世代历期(T)和周限增长率(λ)降低, 而种群加倍时间(Dt)增长; 幼螨期、若螨期和产卵前期明显长于对照, 成螨期和雌螨寿命显著低于对照; 生存率和平均每雌日产雌率明显降低。这些结果证明, 在亚致死剂量下, 阿维菌素和哒螨灵能够降低土耳其斯坦叶螨种群的发育速率, 这对土耳其斯坦叶螨的综合防治策略的制定有积极意义。     

土耳其斯坦叶螨对胡瓜钝绥螨的吸引反应

土耳其斯坦叶螨（Tetranychus turkestani Ugarov ＆ Nikolski）对胡瓜钝绥螨（Amblyseius cucumeris Oudemans）的吸引测试表明,胡瓜钝绥螨对不同螨态的土耳其斯坦叶螨的刺激均能产生显著的吸引反应。胡瓜钝绥螨能捕食土耳其斯坦叶螨的卵,但对土耳其斯坦叶螨的“卵＋丝网＋粪便＋取食斑”没有明显的反应,土耳其斯坦叶螨的若螨I和幼螨是胡瓜钝绥螨最喜欢的猎物。土耳其斯坦叶螨主要通过活动螨对胡瓜钝绥螨产生吸引反应,这种吸引反应能明显提高胡瓜钝绥螨在田间搜索土耳其斯坦叶螨的能力。     

转基因棉对土耳其斯坦叶螨生命参数的影响

为了研究转基因棉花对北疆叶螨优势种土耳其斯坦叶螨Tetranychus turkestani(Ugarov et Nikolskii)种群生命参数的影响,本实验以常规棉中棉49作为对照,构建了叶螨在单价转基因棉新棉33B(Bt)、双价转基因棉中棉41(Bt+CpTI)上的室内种群生命表。结果表明,单双价转基因棉对叶螨的生长发育历期及生殖参数并没有明显影响;且取食常规棉的叶螨种群参数净生殖率、内禀增长率、平均世代周期、种群加倍时间、周限增长率、存活曲线也与单双价棉无显著差异,这说明转基因棉对棉叶螨的生长发育、繁殖及种群增长并无显著影响。     

土耳其斯坦叶螨的生物学特性及其综合防治

叙述新疆棉花上土耳其斯坦叶螨的危害、发生规律,传播、猖獗因素及综合防治技术。     

土耳其斯坦叶螨的发育起点温度与有效积温

本文研究了土耳其斯坦叶螨 Tetranychus turkestani(Ugrou & Nikolski)在实验条件下的发育起点温度和有效积温。结果表明土耳其斯坦叶螨全世代发育起点温度和有效积温分别为雌螨10 .74 73℃和 16 4 .0 1日度 ,雄螨为 11.56 0 3℃和 113.2 9日度。在 15,2 0 ,2 5,30℃的恒温条件下 ,雌螨 1代平均历期分别为 35.15,19.0 5,11.0 4和 8.6 8天。     

短时高温暴露对土耳其斯坦叶螨和截形叶螨的影响

【目的】为了明确土耳其斯坦叶螨Tetranychus turkestani和截形叶螨T. truncatus在高温逆境下的生存特性对其种群发展的影响。【方法】通过短时高温处理试验, 研究了土耳其斯坦叶螨和截形叶螨卵、 幼螨、 成螨在38℃, 42℃和46℃下处理2～6 h后的孵化率和存活率, 以及对其后续发育历期和生殖的影响。【结果】两种叶螨的卵和幼螨在38～46℃下处理2～6 h, 其存活率随着温度和处理时间的增加而降低, 后续发育历期随着温度和处理时间的增加而延长。两种叶螨的雌成螨在38～46℃下处理2～6 h后其存活率、 产卵前期、 产卵期和产卵量均不受影响, 但所产卵的孵化率明显降低, 其中土耳其斯坦叶螨在46℃下处理6 h的孵化率下降了15.5%, 截形叶螨在46℃下处理6 h的孵化率下降了18.0%。【结论】高温暴露主要影响叶螨的孵化率、 存活率和后续的发育历期, 对成螨的寿命和生殖无显著影响; 土耳其斯坦叶螨和截形叶螨对极端高温的适应性存在差异, 土耳其斯坦叶螨对高温的适应性要高于截形叶螨。     

应用实验种群生命表评价加州新小绥螨对土耳其斯坦叶螨和截形叶螨的控制能力

【目的】为了解加州新小绥螨Neoseiulus Californicus(McGregor)对土耳其斯坦叶螨Tetranychus turkestani(Ugarov etNikolski)和截形叶螨Tetranychus truncate(Ehara)的控制能力。【方法】采用实验种群生命表方法进行评价。【结果】以土耳其斯坦叶螨为食时加州新小绥螨的净增值率(R_0=33.236)、内禀增长率(r_m=0.218),大于以截形叶螨为食时的值(R_0=32.458,r_m=0.207),而世代平均周期(T=16.340)和种群倍增时间(t=3.173)小于以截形叶螨为食时的值(T=16.849,t=3.355)。【结论】以土耳其斯坦叶螨为食有利于加州新小绥螨种群的发育和繁殖。     

土耳其斯坦叶螨为害棉叶的生理变化及光谱特征分析

对土耳其斯坦叶螨Tetranychusturkestani(VgarovetNikolski)为害程度不同(0,1,2,3,4级)的棉叶进行光谱测试,并按螨害级数测定光谱测试后棉叶的叶绿素和类胡萝卜素含量。结果表明随着螨害的逐渐加重,棉叶的叶绿素含量逐渐下降,类胡萝卜素含量逐渐上升。光谱测试结果在可见光区,绿峰两侧波段的光谱反射率随螨害加重逐渐增大,差异明显;在近红外区,748~863nm波段的光谱反射率随螨害加重逐渐减小,差异极显著。同时,利用一阶微分求取不同螨害级数棉叶的红边并计算红边参数,通过分析发现,棉花受叶螨危害后单叶光谱的红边发生明显的蓝移现象,红边振幅、红边振幅与最小振幅的比值以及红边峰值面积的值随着螨害加重逐渐减小,结果认为红边能很好地反映棉叶受棉叶螨危害的程度。     

亚致死浓度的铜对虹鳟生理指标的影响

外部环境决定着有机体的功能状态;当有机体与外部环境之间相互关系遭到破坏时,无论机体的生理系统,还是其调节机能都会发生变化。生理指标反映出物体内环境对外部作用作出的反应,以此可确定外部作用的强度,阐明作用机制,确定机体的适应能力,并预测其影响（Хайн...     

毒死蜱亚致死剂量对二斑叶螨实验种群动态的影响

【目的】为探讨毒死蜱(Chlorpyrifos)对二斑叶螨Tetranychus urticae Koch种群动态的影响,室内研究了毒死蜱亚致死剂量对二斑叶螨实验种群成螨和若螨的生长发育、存活和繁殖情况的影响。【方法】用浸虫法进行测定,生命表方法分析亚致死效应。【结果】结果表明毒死蜱亚致死剂量LC25处理成螨后,雌成螨寿命、总产卵量、子代孵化率、性比与对照组无显著差异,其净增值率、内禀增长率、周限增长率以及种群加倍时间显著低于对照组。毒死蜱亚致死剂量LC25处理若螨后,总产卵量、净增值率、世代平均周期显著低于对照组,内禀增长率、周限增长率以及种群加倍时间与对照组无显著差异。扩散试验证明毒死蜱对二斑叶螨有较强的刺激扩散作用。【结论】以上结果说明毒死蜱亚致死剂量对不同发育阶段的二斑叶螨发育和繁殖的影响不同,毒死蜱对二斑叶螨的刺激扩散作用可能是引起二斑叶螨再猖獗的原因之一。     

Sublethal effects of essential oil of Cinnamomum zeylanicum Blume on life expectancy (ex) and age-specific fertility (mx) of two-spotted spider mite,Tetranychus urticae Koch (Acari: Tetranychidae)

Two-spotted spider mite, Tetranychus urticae Koch, is one of the most important pests of agricultural products that have a global distribution. Now, the control is dependent on the use of chemical pesticides. The effects of the sublethal concentrations (LC₁₀ and LC₂₅) of the essential oil of Cinnamomum zeylanicum were evaluated on some parameters of the life table of the pest, at the constant temperature of 30?°C, relative humidity of 40?±?5% and photoperiod of 16L: 8D. Our results showed that the essential oil of cinnamon is effective on female adult stage. Lethal concentration at which 50% mortality (LC₅₀) for the essential oils is from C. zeylanicum on female adult mite was 23.39?μl/L air. Sublethal concentrations of the essential oil of C. zeylanicum also impair the natural biology of the mite. Concentrations of sublethal of essential oil decreased age-specific fertility (m_x) of T. urticae compared with the control. Sublethal concentrations (LC₁₀ and LC₂₅) have reduced the life expectancy (e_x) in egg stage. Sublethal effects of the essential oil of C. zeylanicum and its impact on T. urticae management are discussed.     

Effective concentrations of garlic distillate (Allium sativum) for the control of Tetranychus urticae (Tetranychidae)

The two‐spotted spider mite, Tetranychus urticae Koch, is a worldwide pest that feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of new biological control tactics for population management is crucial. Plant extracts, such as garlic extract (Allium sativum Linn.), may represent viable alternatives, because they are currently considered to be minimum‐risk pesticides. Although garlic is known for its acaricidal properties, the extract concentration that provides the most efficient control has not yet been precisely determined. In this study, we conducted a series of laboratory experiments to determine the susceptibility of adult females to different concentrations of garlic extract. Fresh garlic cloves were steam‐distilled and sprayed using a Potter spray tower. Mortality and fecundity were measured upon treatment with garlic extract concentrations ranging from 0.46 to 14.4 mg/l. Female mortality increased with concentration, with LD₅₀ and LD₉₀ values of 7.49 and 13.5 mg/l, respectively. Reduced fecundity was previously observed at concentrations of 0.36 and 0.74 mg/l. The chemical composition of the Allium sativum distillate was characterized by reversed‐phase high‐performance liquid chromatography coupled with photodiode array detection, GC/MS and Fast GC‐FID against an authentic standard (Standard, Bioextract).Vinyl dithiin, diallyl disulphide, diallyl trisulphide and methyl allyl trisulphide were identified based on their mass spectra. Sesquiterpenoids were identified by their retention index.     

Sublethal effects of Beauveria bassiana on life table parameters of two–spotted spider mite,Tetranychus urticae (Acari: Tetranychidae)

Effects of the entomopathogenic fungus Beauveria bassiana were studied on life table parameters of two-spotted spider mite, Tetranychus urticae feeding on bean and cucumber under laboratory conditions. The developmental periods for all immature stages were not affected by fungal infection on each host plant but the duration of larval stage was significantly longer on bean. The female and male longevity, oviposition period and fecundity were significantly lower on fungus-treated mites but were not different between two host plants. Significant reductions were found on the intrinsic rate of increase (r _m ), the net reproductive rate (R ₀), the finite rate of increase (λ), the mean generation time (T _c ) and the population doubling time (D _t ) as a result of mycosis. Only the mean generation time (T _c ) was influenced considering the effect of host plant, which was shorter on cucumber.     

Sublethal effects of Thymus vulgaris essential oil on life-table parameters of two-spotted spider mite,Tetranychus urticae Koch (Acari: Tetranychidae)

Sublethal effects of Thymus vulgaris were investigated on life-table parameters of Tetranychus urticae Koch (Acari: Tetranychidae) in the laboratory conditions at 25?±?1?°C, 70?±?10% RH and a 14:10?h (L:D) photoperiod. Bioassay was conducted to assess the effect of different concentrations of T. vulgaris essential oil on two-spotted spider mite. LC₅₀ and LC₂₀ of T. vulgaris on T. urticae were calculated as 18.86 and 6.24?μl/litre air for 24?h after treatment. In the sublethal effects, after 24?h exposure to LC₅₀ concentration, mortality, fecundity and longevity of the females that survived from treatment were determined. Results showed that T. vulgaris caused significant reductions in fecundity and longevity of adults. Life-table assay indicated that the intrinsic rate of increase (r _m), net reproductive rate (R ₀), finite rate of increase (λ), mean generation time (T), significantly reduced in treated females compared to control. These results suggest that T. vulgaris could be incorporated in integrated pest management programmes of T. urticae.     

东莨菪内酯对朱砂叶螨实验种群的亚致死效应

为明确东莨菪内酯对朱砂叶螨Tetranychus cinnabarinus (Boisduval) 实验种群的亚致死效应, 为其作为植物源杀螨剂的进一步开发及应用提供理论依据, 在室内采用叶碟饲养的方法, 并利用生命表技术研究了东莨菪内酯亚致死剂量对朱砂叶螨F₀代和F₁代种群生长发育和繁殖的影响。结果表明： 东莨菪内酯LC₄₀, LC₃₀和LC₂₀剂量处理朱砂叶螨雌成螨后, 可刺激F₀代雌成螨产卵, 使产卵量分别增加了73.82%, 186.97%和70.18%, 而对成螨寿命、 产卵期和雌雄性比没有影响; F₁代的卵期、 幼螨期和若螨期与对照没有显著性差异 (P>0.05), 而成螨期和雌成螨寿命均低于对照; 对F₁代繁殖力的影响主要表现为产卵期缩短、 产卵量减少和雌性比下降; 子代种群的净生殖率(R₀)由50.5976最低降至33.9910, 世代平均历期(T)和种群倍增时间(Dt)均低于对照, 各处理后的朱砂叶螨种群均存在适合度缺陷。这些结果表明, 在亚致死剂量下, 东莨菪内酯能够降低朱砂叶螨种群的发育和繁殖速率, 这对东莨菪内酯在有害生物防治上的应用具有积极意义。