两个广西草地贪夜蛾种群对常用杀虫剂的敏感性测定

为了解入侵广西的草地贪夜蛾Spodoptera frugiperda对不同杀虫剂的敏感性,为筛选该虫的有效防治药剂,以及为该虫的抗药性监测提供科学依据。本研究用浸叶法分别测定了田阳种群对13种杀虫剂和南宁种群对5种杀虫剂的敏感性,并比较了两个种群对5种杀虫剂的敏感性差异。结果表明,田阳种群对13种杀虫剂的敏感性依次为:甲氨基阿维菌素苯甲酸盐多杀菌素氯虫苯甲酰胺虫螨腈溴氰菊酯阿维菌素甲氰菊酯氟氯氰菊酯茚虫威呋虫胺毒死蜱高效氯氰菊酯吡虫啉,其中对甲氨基阿维菌素苯甲酸盐、多杀菌素、氯虫苯甲酰胺的敏感性较高,LC_(50)值分别为0.0015、0.0062、0.0075 mg a.i/L,毒力指数分别为480.47、116.24、96.09,其次是虫螨腈、溴氰菊酯、阿维菌素,LC_(50)值分别为0.0296、0.0590、0.0619 mg a.i/L,毒力指数分别为:24.35、12.22、11.64,对其他药剂的敏感性较低,LC_(50)值在0.2544～0.7207 mg a.i/L,毒力指数在1～2.83,除对溴氰菊酯和阿维菌素、甲氰菊酯和氟氯氰菊酯、呋虫胺和毒死蜱、高效氯氰菊酯和吡虫啉的敏感性差异不显著外,对其它药剂差异显著。南宁种群对5种杀虫剂的敏感性依次为:氯虫苯甲酰胺溴氰菊酯氟氯氰菊酯甲氰菊酯高效氯氰菊酯,LC_(50)值分别为0.0142、0.0413、0.0792、0.2081和0.5947 mg a.i/L,毒力指数分别为:41.88、14.40、7.51、2.86和1.00,对各药剂的敏感性均差异显著。南宁和田阳种群对氯虫苯甲酰胺、溴氰菊酯、氟氯氰菊酯、甲氰菊酯和高效氯氰菊酯的敏感性差异均较大,相对毒力指数分别在1.00～41.88和1.00～79.25。两个种群对同种杀虫剂的敏感性也有所差异,除对高效氯氰菊酯的敏感性差异不显著外,对其余药剂的敏感性均差异显著。     

常用杀虫剂对麦长管蚜和禾谷缢管蚜羧酸酯酶活性的抑制及对高效氯氰菊酯的增效作用

【目的】有机磷和氨基甲酸酯类药剂对拟除虫菊酯的增效作用与其对羧酸酯酶(Car E)(EC3.1.1.1)活性的抑制有关。本研究旨在评价13种常用有机磷和氨基甲酸酯类药剂及4种增效剂在防治麦蚜中对高效氯氰菊酯的增效作用。【方法】利用离体活性抑制的方法测定了13种杀虫剂及两种Car E抑制剂对麦长管蚜Sitobion avenae和禾谷缢管蚜Rhopalosiphum padi无翅成蚜Car E活性的抑制中浓度(I50),利用玻璃管药膜法测定了8种杀虫剂及两种抑制剂分别与高效氯氰菊酯以3∶1混配后对两种麦蚜的毒力效果,采用共毒系数(co-toxicity coefficient,CTC)法评价其联合作用。【结果】除硫双灭多威外,测定的其他12种药剂对麦长管蚜Car E活性的抑制作用显著高于对禾谷缢管蚜Car E活性的抑制作用,其中敌敌畏对麦长管蚜和禾谷缢管蚜Car E活性的抑制作用最强,I50分别为(5.40±0.74)×10-8mol/L和(1.41±0.41)×10-5mol/L。抗蚜威、灭多威、丁硫克百威、西维因、三唑磷、丙溴磷、马拉硫磷、敌敌畏及两种增效剂DEF和TPP分别与高效氯氰菊酯联合毒力测定表明,除丙溴磷外,上述药剂均可显著增强高效氯氰菊酯对禾谷缢管蚜的毒力,其中与马拉硫磷混配增效作用最强(CTC=467.59);除灭多威、丙溴磷和马拉硫磷外,其余7种药剂均可显著增强高效氯氰菊酯对麦长管蚜毒力,CTC在146.87~626.30之间,其中与三唑磷混配的增效作用最强(CTC=626.30)。【结论】筛选出对两种麦蚜毒力效果较好的杀虫剂或增效剂与高效氯氰菊酯的组合,包括抗蚜威、丁硫克百威、三唑磷、敌敌畏、DEF和TPP,对小麦蚜虫的有效防治具有重要指导意义。     

禾谷缢管蚜和麦长管蚜玻璃管药膜法敏感毒力基线的建立

【目的】建立禾谷缢管蚜Rhopalosiphum padi（Linnaeus）和麦长管蚜Sitobion avenae（Fabricius）对常用杀虫剂的相对敏感基线。【方法】从田间采集麦蚜在实验室内饲养30代以上,利用玻璃管药膜法测定其对杀虫剂的敏感度,每条毒力基线为2次以上独立测定数据合并后的计算结果。【结果】用玻璃管药膜法建立了包括新烟碱类、吡啶类、氨基甲酸酯类、有机磷类和拟除虫菊酯类共22个药剂品种对禾谷缢管蚜和麦长管蚜3 h的敏感毒力基线。禾谷缢管蚜对新烟碱类药剂吡虫啉和啶虫脒的LC₅₀值分别为0.02和0.007 μg/cm²;对吡啶类药剂吡蚜酮的LC₅₀值为0.124 μg/cm²;对氨基甲酸酯类药剂丁硫克百威、硫双灭多威、灭多威、抗蚜威、西维因的LC₅₀值为0.0026~0.70 μg/cm²;对有机磷类药剂三唑磷、丙溴磷、氧乐果、乐果、马拉硫磷、辛硫磷、敌敌畏、毒死蜱的LC₅₀值为0.005~0.065 μg/cm²;对拟除虫菊酯类药剂三氟氯氰菊酯、高效氯氰菊酯、溴氰菊酯、联苯菊酯、氰戊菊酯、氯氰菊酯的LC₅₀值为0.033~0.240 μg/cm²。麦长管蚜对新烟碱类药剂吡虫啉和啶虫脒的LC₅₀值分别为0.15和0.12 μg/cm²;对吡啶类药剂吡蚜酮的LC₅₀值为0.41 μg/cm²;对氨基甲酸酯类药剂丁硫克百威、硫双灭多威、灭多威、抗蚜威、西维因的LC50值为0.005~0.76 μg/cm²;对有机磷类药剂三唑磷、丙溴磷、氧乐果、乐果、马拉硫磷、辛硫磷、敌敌畏、毒死蜱的LC₅₀值为0.018~0.36 μg/cm²;对拟除虫菊酯类药剂三氟氯氰菊酯、高效氯氰菊酯、溴氰菊酯、联苯菊酯、氰戊菊酯、氯氰菊酯的LC50值为0.20~2.94 μg/cm²。【结论】建立的两种麦蚜对22种杀虫药剂的相对敏感基线,包括当前所有可能用于防治麦蚜的药剂,可以用于以后麦蚜抗药性监测或其他相关研究的参照;禾谷缢管蚜对药剂的敏感度高于麦长管蚜。     

12种杀虫剂对柑橘大实蝇选择行为的影响及击倒作用

柑橘大实蝇是柑橘上的重要害虫。本文分别利用Y型嗅觉仪和饲喂法测定了柑橘大实蝇成虫对12种杀虫剂的选择行为和击倒作用,以期筛选出田间防治柑橘大实蝇的高效农药,并为研发其诱杀剂提供理论依据。结果表明:12种杀虫剂中,吡虫啉、阿维菌素对雌成虫具有极显著的驱避作用;多杀霉素、丁硫克百威、阿维菌素、氟铃脲对雄成虫具有极显著的驱避作用;多杀霉素、毒死蜱、噻嗪酮对雌成虫具有显著的驱避作用;啶虫脒、噻虫嗪、乙酰甲胺磷、高效氯氟氰菊酯和高效氯氰菊酯对柑橘大实蝇雌雄成虫既无驱避作用也无引诱作用。同种药剂对柑橘大实蝇雌雄成虫的击倒时间无显著差异,不同药剂间对柑橘大实蝇成虫的击倒时间有显著差异,其中啶虫脒的击倒时间(KD₅₀<1 min)最短。综合考虑杀虫剂对柑橘大实蝇选择行为的影响及击倒作用,认为啶虫脒更适宜作为柑橘大实蝇诱杀剂中的杀虫剂。     

几类杀虫剂对灰飞虱的相对毒力及田间种群的抗药性现状

采用浸苗法测定了6类11种杀虫剂对灰飞虱Laodelphax striatellus (Fallén)3龄若虫的毒力,并分析比较了江苏句容、通州、楚州、大丰、南京和苏州以及安徽庐江等7地灰飞虱种群对10种杀虫剂的抗药性水平。对云南种群而言,在所测杀虫剂中,以乙酰甲胺磷为标准药剂,氟虫腈的相对毒力最高;噻嗪酮、阿维菌素和噻虫嗪次之;高效氯氰菊酯、IPP（硝基亚甲基类化合物）、毒死蜱、敌敌畏和三唑磷间毒力处于同一数量级,低于阿维菌素等杀虫剂;吡虫啉的相对毒力最低。与云南种群相比,2007年采自苏、皖7个不同地区的灰飞虱种群对噻嗪酮产生了极高水平的抗性,其抗性倍数均超过200倍;对高效氯氰菊酯产生了中高水平的抗性,其抗性倍数为7.8～108.8;安徽庐江灰飞虱种群对三唑磷产生了7.7倍的抗性,对毒死蜱产生了12.0倍的抗性,江苏楚州、南京、大丰和句容灰飞虱种群对毒死蜱产生了5.7～12.6倍的抗性; 所有灰飞虱种群对敌敌畏仍然敏感,对氟虫腈、阿维菌素和新烟碱类杀虫剂吡虫啉、噻虫嗪和IPP等也比较敏感。     

杀虫剂对三角新小卷蛾的毒力与田间防效

研究了常用杀虫剂对三角新小卷蛾Olethreutes leucaspis Meyrick的室内毒力与田间防效.按照毒力降低的顺序,所测定杀虫剂对三角新小卷蛾毒力顺序为甲氨基阿维菌素苯甲酸盐>氟虫腈>三氟氯氰菊酯>溴氰菊酯>阿维菌素>、高效氯氰菊酯>氟虫脲>氰戊菊酯>氟啶脲>毒死蜱>敌百虫.但在田间条件下,各试验药剂均能有效控制三角新小卷蛾的为害.结果表明,敌百虫对三角新小卷蛾的毒力最低,LC50为186.16 mg·L-1,甲氨基阿维菌素苯甲酸盐和氟虫腈的毒力最高,LC50分别为0.67、0.83 mg·L-1,是敌百虫毒力的279.52、224.86倍;三氟氯氰菊酯、溴氰菊酯、阿维菌素、高效氯氰菊酯、氟虫脲和氰戊菊酯亦具有较高的毒力,LC50分别为1.24、1.37、1.60、3.75、5.17、6.71 mg·L-1;毒死蜱和氟啶脲的毒力低于其它药剂.各试验药剂均能有效控制三角新小卷蛾的为害.     

六种杀虫剂对棉铃虫的毒力效果比较

【目的】比较新型杀虫剂对棉铃虫Helicoverpa armigera田间种群的毒力效果,从中筛选出高效农药种类,为当前棉铃虫防治中合理用药提供参考。【方法】在室内采用点滴法,测定了甲氨基阿维菌素苯甲酸盐(甲维盐)、氯虫苯甲酰胺、溴氰虫酰胺、茚虫威、溴虫腈、甲维·茚虫威对4个地理种群棉铃虫3龄幼虫的毒力效果;并比较了甲维盐、氯虫苯甲酰胺对2-5龄幼虫的毒力作用。【结果】6种杀虫剂对3龄幼虫的毒力效果从高到低的顺序依次为:氯虫苯甲酰胺甲维盐甲维·茚虫威溴氰虫酰胺茚虫威溴虫腈;不同地理种群对茚虫威的敏感性差异最大,其次依次为甲维·茚虫威、氯虫苯甲酰胺、溴氰虫酰胺、甲维盐和溴虫腈。甲维盐、氯虫苯甲酰胺对2-4龄幼虫均具有较好毒杀效果,但氯虫苯甲酰胺对5龄幼虫的毒效明显优于甲维盐。【结论】氯虫苯甲酰胺和甲维盐是当前防治棉铃虫的首选农药,且氯虫苯甲酰胺对高龄幼虫毒杀效果较好。     

四种类型杀虫剂对麦长管蚜的温度效应及其与主要解毒酶的关系

为了明确杀虫剂毒力受温度的影响及其程度,本文测定了4大类8种药剂在10～25℃下对麦长管蚜的毒力;并测定了麦长管蚜Sitobion avenae(Fabricius)在不同温度下2个解毒酶和1个靶标酶的活性差异。结果表明,高效氯氰菊酯对麦长管蚜表现不规则负温度系数,啶虫脒表现不规则正温度系数,高效氟氯氰菊酯对麦长管蚜的毒力不受温度影响,其他药剂(辛硫磷、毒死蜱、灭多威、丁硫克百威、吡虫啉)均表现为明显的正温度系数效应,以有机磷类杀虫剂表现最为明显,毒死蜱温度系数高达57.70。酶活性实验表明:麦长管蚜在高温下GST活性增强,羧酸酯酶和乙酰胆碱酯酶活性降低。它们的变化规律表明:GST活性与负温度系数密切相关,正温度系数与羧酸酯酶活性和靶标酶乙酰胆碱酯酶活性有关。     

小麦蚜虫对六种杀虫剂的抗药性及田间药效评价

【目的】为了掌握山东小麦蚜虫对常用杀虫剂的抗药性及田间防治效果,进一步筛选出对小麦蚜虫高效、低毒的药剂品种。【方法】2013-2014年,采用玻璃管药膜法测定了山东省阳谷县和汶上县小麦蚜虫对6种杀虫剂(吡虫啉、高效氯氰菊酯、氧乐果、溴氰菊酯、抗蚜威和氟啶虫胺腈)的抗药性,并于2015年采用田间小区试验的方法在汶上县对8种杀虫剂防治蚜虫田间效果进行了评价。【结果】除了2014年阳谷县禾谷缢管蚜Rhopalosiphum padi种群对高效氯氰菊酯已经产生低水平抗性外,两地区禾谷缢管蚜其他种群和麦长管蚜Sitobion avenae对这6种杀虫剂的敏感性均较高,处于敏感水平。田间防治试验结果表明,50%氟啶虫胺腈WG、20%啶虫脒WP、10%吡虫啉WP和50%抗蚜威WP速效性好,药后3 d对麦蚜的防治效果达76.9%~85.6%;50%氟啶虫胺腈WG、20%啶虫脒WP、10%吡虫啉WP、40%氧乐果EC、25%吡蚜酮WP、50%抗蚜威WP和40%毒死蜱EC持效性好,药后7 d对麦蚜的防治效果达80.0%~97.5%;25 g/L高效氯氟氰菊酯EC药后7 d对麦蚜的防效仅为74.8%,极显著低于其他药剂。【结论】在小麦生产中,可选用高效低毒的氟啶虫胺腈、啶虫脒、吡虫啉、抗蚜威和吡蚜酮对小麦蚜虫进行防治,注意不同类型药剂之间的轮换和交替使用。     

斜纹夜蛾抗性种群中酶抑制剂对杀虫剂的增效作用（英文）

采用浸液生测法研究了斜纹夜蛾Spodoptera litura巴基斯坦抗性种群中酶抑制剂［胡椒基丁醚（PBO）和脱叶膦（DEF)］对丙溴磷、灭多威、硫双灭多威、氯氰菊酯、氯氟氰菊酯、联苯菊酯、茚虫威和多杀菌素等杀虫剂的增效作用。结果表明：PPO和DEF对氨基甲酸酯杀虫剂灭多威和硫双灭多威均具有增效作用,但对有机磷杀虫剂丙溴磷不具有增效作用。两种抑制剂对氯氰菊酯均产生增效作用,但对联苯菊酯没有增效作用。PPO 和DEF增加了氯氟氰菊酯对Multan种群的毒性,但没有增加其对Mailsi种群的毒性。DEF对多杀菌素具有增效作用,但PBO对其没有增效作用。PBO和DEF对氨基甲酸酯杀虫剂、拟除虫菊酯杀虫剂、茚虫威和多杀菌素具有明显的增效作用,这说明细胞色素P450单加氧酶和酯酶的解毒作用至少部分参与了斜纹夜蛾对这些杀虫剂的抗性过程。不过,两种增效剂对杀虫剂增效作用范围有限,暗示对于斜纹夜蛾巴基斯坦种群而言,其他的机制（如靶位点不敏感、表皮穿透作用降低）可能是更重要的抗性机制。     

Biological control by two exotic parasitoids: eight-year population dynamics and life tables of the arrowhead scale

To determine the process of regulation of Unaspis yanonensis (Kuwana) (Hemiptera: Diaspididae) by the two introduced parasitoids, Aphytis yanonensis DeBach et Rosen and Coccobius fulvus (Compere et Annecke) (Hymenoptera: Aphelinidae), the temporal changes in the population density of U. yanonensis as well as the parasitism rates were monitored for eight years before and after the release of the two parasitoids in a Satsuma mandarin orange (Citrus unshiu Marc. (Rutaceae)) orchard. From 2–4 years after the release, the parasitism rate by C. fulvus gradually increased, eventually reaching 70%, while that by A. yanonensis showed a weak increase, remaining under 12%. During this period, the host density decreased to about 1/100 of the initial density. After the drastic decrease, the host density remained under 1/60 of the level previous to the release for at least 2 years with the populations of both parasitoids persisting. To estimate the ability of the two parasitoids to regulate the populations of U. yanonensis, life tables of U. yanonensis under natural conditions and predator/parasitoid-exclusion (bagged) conditions were compared. It was demonstrated that C. fulvus and A. yanonensis impose about 70% mortality rate on the host at mature adult stages and about 30% on the host at immature adult stages. The results have strongly confirmed the high capability of the two parasitoids as biological control agents for U. yanonensis, which was suggested by earlier studies. However, contrary to those studies, the present study did not support the complementarity of the two parasitoids in regulating the host population, suggesting that the effectiveness of C. fulvus alone in regulating the host population at low levels.     

柑桔矢尖蚧生态学研究

1 996～ 1 999年 ,在浙江东南沿海自然变温下对矢尖蚧的发生历期与日平均气温的相关性、各虫态的发育起点温度和有效积温以及生命表等进行了系统的研究。第 1、2、3代雌性寿命分别为 1 0 9.5、1 1 6.2 (一年发生 2代的个体为2 5 6.5 d)和 2 60 .0 d左右 ;完成 1代所需历期分别为 70 .1± 3 .9、67.5± 9.8和 2 1 1 .4± 1 6.5 d。各虫态发生历期与日平均气温明显呈负相关。雌一龄、二龄、产卵前期和雄一龄、二龄、蛹 (包括预蛹 )的发育起点温度分别为 1 1 .5、9.6、8.7、1 4.7、1 3 .6和 1 3 .7℃ ,有效积温分别为 2 61 .8、2 83 .8、5 3 0 .4、1 65 .9、2 0 6.2和 94.0日度。第 1、2、3代每头雌成虫的产卵量分别为 93 .0± 42 .7、1 3 4.2± 65 .6和 1 96.3± 81 .9粒。第 2、3代存在世代重叠现象。第 1、2、3代的种群趋势指数避雨区分别为 2 2 .5 6、3 1 .1 7和 2 .48,露地区分别为 2 1 .0 9、2 9.76和 1 .96,表明在新区的种群自然增长能力很强。研究还揭示了在新区对矢尖蚧种群数量起控制作用的主要因子是自然死亡和失踪 ,因而必需从老发区引进、饲养释放和保护有效的寄生蜂等天敌。     

矢尖蚧发生动态及其寄生性天敌

柑桔矢尖蚧在福建闽北地区一年发生3代。以雌成虫和部分若虫及少数雄蛹越冬．一龄幼蚧盛期,第一代为4月中,下旬。第二代7月上．中旬,第三代9月中旬前后。二龄幼蚧盛期．第一代为5月上、中旬,第二代7月下旬,和第三代9月下旬．后期世代重叠．福建已知寄生蜂6种．其中一种为重寄生蜂,以矢尖蚧黄蚜小蜂为优势种．寄生生蜂自然寄生率最高达49.1%。     

PREDATION OF THE LADYBEETLE CHILOCORUS KUWANAE ON THE SCALE UNASPIS YANONENSIS

Abstract The prey consumption of ovipositing female adults of the ladybeetle Chilocorus kuwanae on the scale Unaspis yanonensis was found to be significantly greater than that of the male adults. At 25°C one female adult ladybeetle, on average, would consume 42. 7 female scale adult per day while one male adult only destroyed 22. 3 female scale adults. However, after a deprivation of the prey for 48 h, this difference was eliminated. A C. kuwanae female adult had to prey on at least 15 U. vanonensis female adults in order to lay eggs. The funcional responses of the beetle adults to densities of different stages of the scale followed Holling's type 1. The functional responses to female scale adults indicated that the maximum prey consumption went up with the increase in temperature from 16°C to 35°C, and dropped sharply at 37°C. However, temperature did not alter the type of the functional response. Rased on the predation of C. kuwanae adults on U. yanonensis female adults, the minimum critical, optimal and maximum critical temperatures for their attack were estimated to be 10. 6°C, 31. 5°C and 38. 2°C respectively. The increase in predation space or in predator density could result in a reduction in the attack rat-e, but with the increase of predator density, the effect of predation space became much smaller. C. kuwanae adults preferred male pupae to other stages of the scale, and their preference for various stages of the prey was in the order of male pupae, 2nd-instar male nymphs, 2nd-instar female nymphs, adult females and kinstar nymphs.     

Effects of pesticide applications on the euonymus scale (Homoptera: Diaspididae) and its parasitoid, Encarsia citrina (Hymenoptera: Aphelinidae)

Novel biorational insecticides are rapidly replacing more toxic, broad-spectrum compounds to control pests of ornamental plants. These new formulations are widely regarded as safe, effective, and environmentally sound with minimal impact on nontarget organisms. We tested several biorational and traditional insecticides for their ability to control euonymus scale, Unaspis euonymi (Comstock), and their potential impacts on the aphelinid parasitoid, Encarsia citrina (Crawford). Soil-applied acephate and foliar-applied pyriproxyfen exhibited superior control of euonymus scale, but also reduced numbers of surviving E. citrina. Imidacloprid failed to control euonymus scale and decreased parasitism by E. citrina. Thus, the potential impact of a pesticide on biological control is not necessarily predicted by its potential longevity, mode of delivery, or its toxicity to the target pest. Finding the best fit of a compound into an integrated pest management program requires a consideration of all these factors and direct study of effects on the natural enemies of pests.     

Seasonal Development and Population Fluctuations of Arrowhead Scale,Unaspis yanonensis (Homoptera: Diaspididae), in Citrus orchards in Jeju,Korea

Arrowhead scale, Unaspis yanonensis (Kuwana), feeds on the foliage, stems, and fruits of citrus trees, and causes tree dieback when heavy infestations occur. The objective of this study was to collect basic data to establish seasonal management strategies for U. yanonensis. The abundances of male nymphs and female adults were monitored in unsprayed citrus orchards. The overwintered females started to produce their progenies (1st gen.) from mid-May. The populations of the 1st nymphs in the 1st generation showed a bimodal occurrence pattern, with a 1st larger peak between late May and early June, and a 2nd smaller peak in June. The nymphs in the 2nd generation, which were laid from newly developed females, were observed from late July, and the 1st peak occurred in mid-August, followed by an obscure later peak (the 2nd peak) around late September. The numbers of live females for the overwintered populations began to decrease gradually from early June by the impact of the predacious Chilocorus kuwanae, as well as by natural mortality factors, and dropped to a low level in mid-July. When there were abundant predator attacks, the U. yanonensis female populations sharply decreased from early June and were almost nonexistent in July. New female adults (1st generation adults) appeared from late June and peaked in mid-July. The 2nd generation female adults, consequently, the overwintering generation, occurred from mid- September, and gradually increased to late October. Overall, these results will be useful in terms of management strategies for U. yanonensis in citrus orchards.     

有机磷农药对微藻的毒性作用研究概述

论文就有机磷农药对藻类生长的影响、毒性机理以及对浮游植物群落结构的影响进行综述。相对于水生甲壳类和鱼类,有机磷农药对藻类毒性较低,EC₅₀一般高于1mg/L,对藻类生长的影响大致呈现低浓度促进、高浓度抑制的趋势,有机磷农药之间及其与其它化合物之间具有联合毒性作用。有机磷农药对藻细胞酶活性具有一定影响,而对光合作用的影响也是有机磷农药对藻类毒性效应的重要致毒机制。浮游植物对有机磷农药敏感性差异以及施药引起的浮游动物对藻类的选择性摄食,可能会导致水生态系统中浮游植物群落结构的变化。     

杀虫剂对烟粉虱成虫毒力的微量筛选方法

采用直径为18mm的指形管代替常规浸叶法中的培养皿,研究不同寄主植物叶片和琼脂浓度对烟粉虱Bemisia tabaci(Gennadius)成虫自然死亡的影响,并用吡虫啉和啶虫脒为供试药剂对烟粉虱成虫毒力的筛选方法进行比较。结果表明:选用棉花叶片和14g.L-1的琼脂时,指形管内烟粉虱成虫72h自然死亡率最低,只有(5.4±1.5)%;采用此方法就吡虫啉和啶虫脒对烟粉虱成虫的毒力进行测定,测定结果重复性较好,节省药剂用量,无需对烟粉虱成虫麻醉,操作简便,达到微量活体筛选的目标。     

两种虫酰肼类新化合物对五种鳞翅目害虫的生物活性

为了比较虫酰肼及其衍生物对鳞翅目 5 种害虫的毒力 ,以虫酰肼为对照药剂,分别采用浸叶法、浸虫法和点滴法测定了虫酰肼衍生物 0593 (Ⅲ f) 和 0673 对甜菜夜蛾 Spodoptera exigua（Hübner）、斜纹夜蛾 Prodenia litura (Fabricius)、小菜蛾 Plutella xylostella (Linnaeus)、棉铃虫 Helicoverpa armigera(Hübner)和玉米螟 Ostrinia furnacalis(Guenée)的毒力;通过浸叶法系统研究了虫酰肼和虫酰肼衍生物 0593 对甜菜夜蛾生长发育的影响。结果表明：0593 和 0673 对甜菜夜蛾 4 龄幼虫的触杀毒力分别是虫酰肼的 11.3 倍和 7.4 倍,对斜纹夜蛾 4 龄幼虫触杀毒力分别是虫酰肼的 30.4 倍和 24.7 倍,对小菜蛾 3 龄幼虫浸虫处理的毒力分别是虫酰肼的 4.7 倍和 4.5 倍 ,对棉铃虫3龄幼虫的触杀毒力分别是虫酰肼的 15.5 倍和 15.2 倍,对玉米螟 4 龄幼虫的触杀毒力分别是虫酰肼的 1.3 倍和 2.0 倍,较虫酰肼的毒力都有很大提高,而0593 和 0673 对 5 种害虫的毒力差异不显著。用虫酰肼和 0593 处理甜菜夜蛾 2 龄幼虫,都能导致存活幼虫陆续死亡;化蛹率和正常蛹数降低;成虫羽化率、单雌产卵量和卵的孵化率显著减少,对后代的繁殖力影响显著;在相同处理浓度下,0593 较虫酰肼对甜菜夜蛾后代繁殖力的不利影响更大。因此,0593 是较虫酰肼杀虫毒力更高、对生长发育和繁殖力不利影响更大的药剂,开发应用价值很大。