叶螨危害与苹果叶片无机营养关系初步研究

应用模糊聚类和统计分析方法研究了苹果叶片 P,K,Mo,Zn,Mn,Cu,B,Ca,Mg 和Fe 十种无机营养元素与苹果全爪螨和山楂叶螨危害的关系。结果表明:10种元素与不同果园或地域两种叶螨的发生比例及密度相关;在品种、树龄相同条件下10种元素含量的差异可能是制约叶螨发生的原因之一;苹果不同品种间10种营养元素含量的差异与苹果全爪螨密度有关;Mo,Fe,Mn 和 K 可能是影响两种叶螨发生危害的重要营养元素,它们在叶片上分布的不均匀性可能是导致两种叶螨在同一叶片上生态位分离的主要原因。     

哒螨灵与柴油或四螨嗪对山楂叶螨的室内毒力测定

采用玻片浸渍法，进行了哒螨灵与柴油或四螨嗪混用对山楂叶螨的室内联合毒力测定试验。结果表明：哒螨灵与柴油不同配比的混合物对山楂叶螨均有显著的增效作用，其中1：10混配物的共毒系数(CTC)为291．65，增效作用幅度最大；哒螨灵与四螨嗪的混合物对山楂叶螨也均有一定的增效作用，其中2：1混配物的增效作用幅度最大。     

山楂叶螨种群内禀增长力的研究

在23±O.5℃温度条件下,室内饲养山楂叶螨Tetranychus viennensis(Zacher),组建其生殖力表,以测定该种群生物学参数,其结果如下:种群内禀增长力r_m为O.1240,净生殖率Ro为20.8156,平均世代周期T为24.4865。该种群的干扰反应时间可用公式:T=-8.06451n(1-M)计算(M表示种群受干扰后的死亡率)。     

温度对玉米截形叶螨生长发育的影响

在15℃－35℃恒温条件下，玉米截形叶螨Tetranychus truncatus的发育历期与温度呈负相关；雌、雄螨1代发育起点温度分别在12．60和12．65℃，有效积温各为137．78和121．52日度；25℃－35℃时卵孵化率和幼若螨存活率都较高，并且发育速率较快，该范围是截形叶螨生长发育的最适度。     

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。     

鸡油菌属真菌2个洲际间断分布种

 分别从云南省剑川县和香格里拉县采集到鸡油菌属(Cantharellus)真菌的东亚/北美/大洋洲间断分布种红鸡油菌(C. cinnabarinus)和东亚/北美间断分布种太平洋金色鸡油菌(C. formosus)。对两者进行了形态学描述和基于核糖体大亚基 (LSU nrDNA) 的分子系统学分析。研究结果表明中国原被定为C. cinnabarinus的标本代表着一个尚未发表的新分类单元,而本文报道的红鸡油菌为真正的C. cinnabarinus;太平洋金色鸡油菌为中国新纪录种,以其暗褐色的子实体区别其近似种C. cibarius。研究标本保存于中国科学院昆明植物研究所隐花植物标本馆。     

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