西双版纳棚栽辣木主要害虫及防治

介绍了西双版纳棚栽辣木存在的主要害虫:朱砂叶螨(Tetranychus cinnabarinus Boisduval)、美洲斑潜蝇(Liriomyza sativae Blanchard)、斜纹夜蛾(Prodenia litura Fabricius)和小菜蛾(Plutella xylostella L.)为害症状和防治。     

Transcription and induction profiles of two esterase genes in susceptible and acaricide-resistant Tetranychus cinnabarinus

The carmine spider mite Tetranychus cinnabarinus is the most serious of crop mite pests in China. Their ability to rapidly develop resistance to acaricides has caused difficulty in controlling this mite. In this study, the molecular mechanism of acaricide resistance associated with esterase genes TCE1 and TCE2 was investigated in susceptible and acaricide-resistant strains of T. cinnabarinus. The quantitative real-time PCR (qrtPCR) method was adopted to compare the expression level of two esterase genes TCE1 and TCE2 among four different strains (abamectin-resistant, AbR; fenpropathrin-resistant, FeR; omethoate-resistant, OmR and susceptible strains, S) of T. cinnabarinus. The relative expression level of TCE2 was 1.39-2.47 fold in the three resistant strains compared with the S strain. And after inducing with abamectin, fenpropathrin, and omethoate the highest expression level of TCE2 in the S was 1.64-, 2.92- and 2.24-fold compared with the control, respectively, and this difference was found to be significant. However, there was no obvious difference of the mRNA relative expression levels of TCE1 genes among the four strains, and those of TCE1 were not higher than the control throughout the study. Furthermore, the expression modes of TCE1 and TCE2 in AbR and FeR were similar with that in the S after being treated with abamectin and fenpropathrin, respectively. These results indicated that the enhanced expression of esterase gene TCE2 was associated with acaricide-resistance in T.cinnabarinus.     

溴虫腈与哒螨灵对朱砂叶螨的联合作用

为明确溴虫腈与哒螨灵的联合杀螨活性,采用玻片浸渍法测定了溴虫腈与哒螨灵不同配比混剂对朱砂叶螨雌成螨的杀螨活性,并以共毒因子法和共毒系数法评价混剂的增效作用。结果表明,溴虫腈和哒螨灵对朱砂叶螨雌成螨处理后24 h的致死中质量浓度(LC50)分别为8.80、17.69mg/L;溴虫腈与哒螨灵的质量比为49∶51、47∶53、45∶55时增效最明显,对朱砂叶螨处理后24 h的共毒系数分别为177.94、178.49、173.73,LC50分别为6.65、6.72、7.00 mg/L,其毒力分别是哒螨灵的2.66倍、2.63倍、2.53倍。因此,45%~49%溴虫腈与51%~55%哒螨灵混合具有显著的增效作用。     

云南鲜切花主产区朱砂叶螨抗药性测定

采用玻片浸渍法测定了云南鲜切花主产区玫瑰和香石竹植株上朱砂叶螨[Tetranychus cinnabarinus(Boisduval)]对阿维菌素、甲氨基阿维菌素苯甲酸盐、溴虫腈、丁醚脲、炔螨特和哒螨灵的抗性。结果表明,昆明北郊和呈贡地区玫瑰上的朱砂叶螨雌成螨对阿维菌素与甲氨基阿维菌素苯甲酸盐产生了极高的抗药性,阿维菌素对2个地区的朱砂叶螨的LC50分别为40.25和19.67mg/L,相对毒力指数分别为敏感品系的2441.08和1192.86倍;甲氨基阿维菌素苯甲酸盐对其LC50分别为118.18和9.24 mg/L,相对毒力指数是敏感品系的2805.73和219.35倍。昆明北郊的朱砂叶螨对溴虫腈的相对毒力指数是敏感品系的2371.40倍,呈贡和晋宁的朱砂叶螨对溴虫腈的相对毒力指数是敏感品系的162.01和173.38倍。丁醚脲对昆明北郊、呈贡和晋宁朱砂叶螨的LC50分别为244.58、385.41和54.93 mg/L,相对毒力指数在3.01～21.10倍。昆明北郊、呈贡和晋宁的朱砂叶螨种群对炔螨特和哒螨灵的LC50分别为155.39、424.49和62.70 mg/L,其相对毒力指数是敏感品系的6.45倍、17.63倍和2.60倍。朱砂叶螨对药剂抗性水平趋势从高到低为阿维菌素、甲氨基阿维菌素苯甲酸盐>溴虫腈、丁醚脲>炔螨特、哒螨灵,抗性最高的地区为昆明北郊,晋宁相对较低。     

准噶尔山楂叶总黄酮的超声波提取及抗氧化研究

[目的]为准噶尔山楂叶的综合利用和深度开发提供一定的参考。[方法]利用超声波法提取准噶尔山楂叶中的总黄酮,用总黄酮提取率作为衡量提取工艺的指标,对影响超声波提取的多个因子进行单因素、正交试验分析。[结果]准噶尔山楂叶中的总黄酮的超声波提取最佳条件为:乙醇浓度80%,提取温度50℃,提取时间50 min,提取功率75 W,总黄酮的得率高达84.50%;影响总黄酮得率的主次因素依次为:乙醇浓度提取时间提取功率提取温度。[结论]准噶尔山楂叶总黄酮有较强的清除自由基能力,表现出明显的抗氧化性。     

Quantitative impact assessment of spray coverage and pest behavior on contact pesticide performance

BACKGROUND: Standard procedures for evaluation of pesticide performance do not take into account pest behavioral response or incomplete spray coverage. In this study, a series of laboratory experiments was conducted with two non‐systemic miticides (propargite and hexythiazox) applied to cotyledon cotton plants, which were subsequently infested with spider mites. The results of these laboratory experiments are discussed through a comprehensive pest population dynamics model. RESULTS: When cotton leaves were submerged in miticide solutions, both miticides provided effective control of spider mites. In a two‐choice test it was demonstrated that propargite was repellent to spider mites, but not hexythiazox. Finally, the spray coverage on cotton plants was varied, and, for both miticides, significantly positive relationships between spray coverage and spider mite mortality were shown. However, propargite required higher spray coverage (20%) than hexythiazox (10%) to control spider mites. A theoretical model showed that, without repellency, the pesticide performance is positively correlated with target pest mobility. If the pesticide is repellent, the probability of exposure decreases, especially for a less mobile pest. CONCLUSION: With an experimental and theoretical modeling approach, it was demonstrated how the combination of behavioral avoidance and low spray coverage can markedly reduce pesticide performance. Copyright © 2012 Society of Chemical Industry     

杜鹃属常绿杜鹃组织培养的研究进展

常绿杜鹃树形优美,花色艳丽,具有较高的观赏价值和园林利用价值。但由于常绿杜鹃的繁殖困难,培育年限长,所以在市场上常常供不应求。随着植物组织培养技术的发展,近年来常绿杜鹃的组培快繁技术也有了一定的进展。现从常绿杜鹃组培快繁技术的外植体的选择、外植体的消毒方法、培养基的选择、不同激素对外植体的影响、增殖培养和生根培养以及生根苗移栽等方面作以综合性论述,以期为常绿杜鹃组培快繁技术提供借鉴。     

七种药剂对朱砂叶螨室内毒力测定及田间药效试验

用7种药剂对蔬菜上朱砂叶螨的室内毒力和田间药效进行测定。结果表明:7种药剂中杀螨活性最高的是抗生素类-阿维菌素和甲氨基阿维菌素苯甲酸盐,24h时LC50分别为0.1300和0.7118mg/L;唑螨酯和哒螨灵的效果次之,LC50分别为1.4808和3.1586mg/L;螺螨酯的敏感性最低,24h时LC50为1 181.4348mg/L;田间试验结果表明:1.8%阿维菌素乳油、1%甲氨基阿维菌素苯甲酸盐乳油和15%哒螨灵乳油对朱砂叶螨的防效都非常好,2d的防效均达98%以上,14d的防效为100%。40%炔螨特乳油和5%唑螨酯悬浮剂在药后7和14d的防效达99%以上;240g/L螺螨酯悬浮剂表现出速效性稍低,持效性良好,药后14d防效为99.94%。     

噻虫嗪与氯虫苯甲酰胺对非靶标害虫土耳其斯坦叶螨生长发育的影响

【目的】 研究噻虫嗪与氯虫苯甲酰胺两种药剂,对非靶标害虫土耳其斯坦叶螨生长发育及种群参数的影响。【方法】 采用玻片浸渍法、叶碟法,研究土耳其斯坦叶螨对两种药剂的敏感性、生命参数变化。【结果】 经氯虫苯甲酰胺和噻虫嗪处理的土耳其斯坦叶螨成螨死亡率与对照均无明显差异;氯虫苯甲酰胺处理叶螨成螨后,次代除若Ⅱ期外,未成熟期的存活率均高于对照,而噻虫嗪处理时,次代若Ⅱ期的存活率高于对照,卵期、幼螨期和若Ⅰ期的存活率低于对照;经氯虫苯甲酰胺处理后,与对照和噻虫嗪处理相比,产卵前期明显缩短,世代显著延长,且日产卵量显著增多;氯虫苯甲酰胺处理的种群净增殖率R₀ 、内禀增长率r_m 、周限增长率λ比对照和噻虫嗪处理增大,而施用噻虫嗪的叶螨平均世代历期T、种群加倍时间t比对照和施用氯虫苯甲酰胺延长。【结论】 氯虫苯甲酰胺有刺激土耳其斯坦叶螨增长的作用,而噻虫嗪无影响。     

保护地黄瓜截形叶螨种群动态的研究

截形叶螨在保护地黄瓜上的空间格局为聚集分布．分布的基本成分为个体群,聚集强度与叶螨的密度有关,随着密度的上升而下降;截形叶螨在保护地黄瓜上呈指数增长,模型为N1=1．3634e^0.31261(R=0．9174^**)。应用最优分割法将截形叶螨种群动态划分为3个阶段：初建期、发展期和高峰期。在种群初建期,截形叶螨开始迁入,数量较低,以扩散为主,分布不均匀,聚集强度较高;在发展期,截形叶螨种群不断扩散,分布日均匀,聚集强度逐渐下降;在高峰期,截形叶螨种群数量急剧增长到高峰,聚集强度继续下降,此阶段由于黄瓜接近成熟及受害枯萎．截形叶螨因缺少食物而数量急剧下降。