两种替代猎物对日本刀角瓢虫生长发育及生殖力的影响

为明确替代猎物对日本刀角瓢虫人工饲养的效果,以烟粉虱卵为对照,研究了地中海粉螟卵和米蛾卵对日本刀角瓢虫生长发育及繁殖力的影响。结果表明,饲喂米蛾卵的日本刀角瓢虫存活率为17.16%,发育历期显著延长,雌虫寿命显著缩短;饲喂地中海粉螟卵处理的存活率为77.82%,雌虫寿命显著延长。瓢虫幼虫期和成虫期营养对成虫产卵能力有明显影响:幼虫期饲喂地中海粉螟卵,成虫期分别饲喂米蛾卵和地中海粉螟卵,产卵量极显著降低(分别为64.45粒和53.82粒);幼虫期饲喂地中海粉螟卵,成虫期饲喂烟粉虱卵,产卵量(539.10粒)与对照组无显著差异;幼虫期饲喂烟粉虱卵,成虫期分别饲喂地中海粉螟卵和米蛾卵,产卵量极显著降低(分别为59.30粒和71.38粒)。因此,米蛾卵不适于日本刀角瓢虫饲养,地中海粉螟卵可作为瓢虫幼虫期饲养的替代猎物。     

不同温度锻炼对高温胁迫下Q型烟粉虱存活及生殖的影响

［目的］ 明确不同温度锻炼对高温胁迫下Q型烟粉虱存活及生殖的影响。［方法］ 将Q型烟粉虱成虫在45 ℃下暴露1 h直接进行高温胁迫,及温度锻炼后再胁迫,即在不同温度(10、33、39 ℃)下暴露0.5 h,再45 ℃处理1 h,然后在26 ℃条件下饲养,观察其存活率、寿命及产卵量。 ［结果］ 在产卵量无明显变化时,低温锻炼后雌雄虫寿命缩短,以存活率升高的方式维持其种群。高温锻炼后存活率降低,以延长雌虫寿命的方式,使其种群数量维持在一定水平。［结论］ 不同温度锻炼后,Q型烟粉虱的种群动态与存活率、寿命、产卵量的变化之间存在着权衡。     

卵和蛹短时高温对草地贪夜蛾生长发育的影响

为明确草地贪夜蛾Spodoptera frugiperda卵和蛹经短时高温处理对其生长发育的影响,将草地贪夜蛾卵和蛹在34、38、42、46℃高温下分别处理2、4、6 h后,测定短时高温下草地贪夜蛾卵的孵化率、不同虫态的发育历期、蛹的羽化率和雌成虫及其子代的繁殖力等指标。结果表明:随着温度升高和高温持续时间延长卵的孵化率逐渐降低,卵在38℃及以上处理6 h或高温46℃处理2 h以上孵化率显著降低;46℃处理6 h的孵化率最低为12.21%,幼虫不能成活;在42℃处理4 h以上和46℃处理2 h以上卵的发育历期延长,与对照差异显著,幼虫的发育历期显著短于对照,蛹的发育历期与对照比无显著差异;38℃处理6 h、42℃处理6 h成虫的产卵量显著低于对照。短时高温处理蛹后,雌蛹和雄蛹在46℃处理2～6 h后羽化率分别为0～15.00%和0～6.75%,均显著低于对照,雌蛹在42、46℃下的羽化率高于雄蛹,蛹在38℃处理6 h和42℃处理2 h以上后羽化的成虫产卵量较低,为121.25～186.75粒。表明高温38℃以上持续6 h或42℃以上持续2 h以上草地贪夜蛾种群生长会受到抑制。     

寄主植物对B型烟粉虱个体发育和种群繁殖的影响

同一原始种群B型烟粉虱[Bemisia tabaci(Gennadius)],分别在甘蓝、一品红、棉花、番茄和黄瓜连续隔离饲养大约20代后形成5种对应的烟粉虱种群,研究其在甘蓝上各虫态大小、存活率、发育历期、成虫寿命和平均产卵量等生物学参数。在(25±1)℃条件下,一品红种群烟粉虱的1、2、3龄若虫体长和宽均显著低于其他4个种群烟粉虱;发育时间以甘蓝和一品红种群烟粉虱(20.44、19.69d)显著高于番茄种群烟粉虱(19.13d);雌虫寿命以甘蓝种群烟粉虱显著低于一品红、棉花、番茄和黄瓜种群烟粉虱;平均单雌产卵量以一品红种群烟粉虱(169.30粒)显著高于其他4个种群烟粉虱;5个种群烟粉虱在甘蓝上的总存活率均无显著差异。     

虱螨脲对小菜蛾成虫繁殖力及子代种群发展的影响

为探究虱螨脲对小菜蛾Plutella xylostella成虫的亚致死作用,通过残留药膜法或饲喂法使用50 mg/L虱螨脲对小菜蛾成虫进行处理,分别测定小菜蛾成虫繁殖力、寿命和卵孵化率,通过建立小菜蛾成虫子代生命表确定虱螨脲处理成虫对其后代的影响。结果表明,残留药膜法处理后,小菜蛾成虫单雌产卵量和卵孵化率分别比对照显著降低39.09粒和19.38个百分点;饲喂法处理后,小菜蛾成虫单雌产卵量、雌成虫寿命和卵孵化率分别比对照减少13.42粒、1.56 d和72.03个百分点,卵孵化率与对照差异显著。虱螨脲处理后,小菜蛾成虫子代1龄幼虫存活率、雌成虫寿命、F_1代单雌产卵量和F_1代卵孵化率分别为74.29%、5.90 d、146.65粒和84.43%,均显著低于对照,种群趋势指数降低,表明对子代种群发展有一定的干扰作用。此外,虱螨脲处理小菜蛾雌、雄虫对其产卵量无影响,但处理雌虫显著降低卵孵化率,处理雄虫对卵孵化率无明显影响,说明虱螨脲作用于小菜蛾成虫,仅对卵子形成及受精卵的胚胎发育过程产生影响,而对精子的生成及转移无影响。表明虱螨脲可通过成虫取食或接触而控制小菜蛾种群发展。     

螺虫乙酯对B型烟粉虱毒力及部分生物学参数的影响

为系统评价新药剂螺虫乙酯(spirotetramat)对B型烟粉虱(Bemisia tabaci biotype B)的生物活性及生物学参数的影响,采用浸渍法测定了螺虫乙酯及对照药剂吡虫啉对B型烟粉虱各个虫态的室内毒力、成虫寿命、产卵量及所产卵孵化率的影响。结果表明,螺虫乙酯对2龄若虫毒力最高,LC₅₀为4.07 mg/L,为吡虫啉的2.73倍,对卵及成虫毒力较低,且显著低于吡虫啉;12.5 mg/L螺虫乙酯处理后,成虫寿命为17.3天,较空白对照显著缩短,吡虫啉与空白对照无显著差异;12.5 mg/L螺虫乙酯处理后平均产卵量为5.0粒,所产卵的平均孵化率为3.23%,显著低于空白对照和吡虫啉处理,吡虫啉与空白对照无显著差异;100 mg/L螺虫乙酯处理24 h后对烟粉虱成虫驱避率为52%,驱避效果较差。     

B型和Q型烟粉虱成虫经高、低温暴露后的存活特性研究

研究了B型和Q型烟粉虱成虫经过高、低温暴露后的存活情况.结果表明,2种生物型烟粉虱成虫对高温具有较强的适应性,在45℃下暴露1 h,部分成虫仍能存活;B型和Q型烟粉虱成虫在2～5℃下暴露1～8 d后存活率迅速下降,成虫在2℃下暴露4 d或在5℃下暴露8 d后全部死亡.     

红星盘瓢虫取食烟粉虱和桃蚜的生物学特性研究

本文研究了取食烟粉虱Bemisia tabaci（Gennadius）和桃蚜Myzus persicae（Sulzer）对红星盘瓢虫Phrynocaria congener（Billberg）生物学特性的影响,结果表明,取食不同虫态的烟粉虱时,红星盘瓢虫从卵到成虫不同虫态的发育历期和存活率差异不显著;取食不同虫态的桃蚜时,红星盘瓢虫一、三和四龄幼虫的发育历期和四龄幼虫的成活率差异显著。分别取食烟粉虱的混合种群（卵、各龄若虫和蛹）和桃蚜的混合种群（卵和各龄若虫）时,瓢虫从卵到成虫的发育历期和存活率差异显著,分别为13.3d和15.7d、81.1%和70.0%。红星盘瓢虫取食烟粉虱和桃蚜的产卵前期差异不显著;但成虫寿命和平均单雌产卵量差异显著,分别为64.6d和86.0d、389.4粒和960.4粒。红星盘瓢虫捕食烟粉虱和桃蚜的内禀增长率（rm）分别为0.0967和0.0964;净增殖率（R0）分别为118.7573和355.3586;世代平均历期（T）分别为49.4d和60.9d;周限增长率（λ）分别为1.1015和1.1012。     

印楝素亚致死浓度对烟粉虱实验种群的生物活性

在室内条件下,以2个亚致死浓度（0.15和0.30mg/L）喷雾处理烟粉虱1、5日龄卵,明确了印楝素亚致死浓度对烟粉虱实验种群发育、存活、繁殖均具有显著的抑制作用。其中,印楝素处理1日和5日龄卵分别使幼期（卵至成虫羽化）发育历期延长0.92至2.84d,幼期存活率降低了56.3%至89.6%,若虫虫体长宽减小,雌成虫寿命降低29.8%至48.6%,平均单雌产卵量降低49.8%至72.5%。清水对照、0.15mg/L和0.30mg/L印楝素溶液处理1日龄卵,烟粉虱实验种群的内禀增长率分别为0.227、0.0742和0.060,净增殖率依次为36.40、7.29和5.33;处理5日龄卵时两者分别为0.126、0.114和0.059与39.192、3.59和4.93。     

转Bt基因棉和常规棉对烟粉虱生长发育和繁殖的影响

在实验室恒温和大田自然条件下，通过对转Bt基因棉国抗22和常规棉亲本泗棉3号的对比试验研究，探讨两种棉花对烟粉虱生长发育和繁殖的影响。结果表明：28℃恒温条件下，在花铃期棉花上，国抗22上的B型烟粉虱发育历期（从卵到成虫羽化）比常规棉亲本泗棉3号短17．79％、存活率高4．5％、产卵量高39．62％、雌虫寿命长12．14％、内禀增长率rm大20．18％；在苗期棉花上，国抗22上的B型烟粉虱发育历期比泗棉3号短14．14％、雌虫寿命长17．46％、rm大1．47％，存活率和产卵量差异不显著。在大田自然变温条件下，国抗22上烟粉虱发育历期比泗棉3号短13．6％。在同一品种棉花上，饲养在苗期棉花上烟粉虱的发育历期较花铃期棉花长。结果显示，花铃期棉花比苗期棉花更有利于烟粉虱的生长发育和繁殖；与常规棉亲本相比，转Bt基因棉花上烟粉虱的种群扩增速率更快。     

枯草芽胞杆菌对离体荔枝果实霜疫霉病、炭疽病的防治效果

为了进一步明确从土壤中筛选得到的拮抗细菌OR-1、OR-2、OR-3、ON-6的分类地位和生防效果,采用形态学观察、理化特性结合分子生物学方法,鉴定这4株细菌皆为枯草芽胞杆菌Bacillussubitilis.拮抗菌对荔枝霜疫霉菌、炭疽菌菌丝生长均具有明显抑制作用,ON-6菌株的发酵液对菌丝生长的抑制率最高,分别为92.34％和70.36％,其次是OR-1菌株.拮抗菌处理组褐变指数均小于对照组以及杀菌剂处理组,且差异达显著水平(P＜0.05),OR-1菌株防褐变效果最好.常温下,拮抗菌发酵液对离体鲜果病害防治效果优于对照组和杀菌剂处理组,其中ON-6菌株的防治效果最佳;4℃低温储藏处理40天后,拮抗菌发酵液处理组的防治效果高于对照和杀菌剂处理组,且差异显著(P＜0.05),以ON-6和ON-3菌株的防治效果最佳.表明拮抗菌发酵液对荔枝鲜果上的霜疫霉菌和炭疽病菌有一定的抑制作用.     

草间钻头蛛体内沃尔巴克氏体的去除及其感染对宿主生殖和适合度的影响

采用在草间钻头蛛Hylyphantes graminicola的饮水和人工饲料中添加四环素的方法研究了蜘蛛体内沃尔巴克氏体(Wolbachia)的去除.同时,通过设置草间钻头蛛Wolbachia感染种群与未感染种群之间不同的交配方式,研究Wolbachia感染对草间钻头蛛生殖和适合度的影响.结果显示,在草间钻头蛛的饮水和人工饲料中添加四环素均能部分去除草间钻头蛛体内的Wolbachia,在供试最高浓度下,去除率分别为40％和50％.4种不同的交配组合下,草间钻头蛛雌蛛均能产卵,卵的孵化率差异不显著,Wolbachia感染对草间钻头蛛的生殖无影响.感染Wolbachia的草间钻头蛛所产第1卵袋的卵历期为6.65d,极显著高于未感染Wolbachia的卵历期(P =0.008).感染与未感染Wolbachia的草间钻头蛛种群世代存活率、性比以及适合度均无显著差异.     

溴氰虫酰胺和氯虫苯甲酰胺对三种鳞翅目害虫的毒力作用比较

为比较溴氰虫酰胺和氯虫苯甲酰胺对甜菜夜蛾、玉米螟和小地老虎的作用差异,采用浸卵法、浸叶法、饲喂毒营养液法等测定了溴氰虫酰胺和氯虫苯甲酰胺对3种害虫的卵、3龄幼虫和成虫的毒力,以及对其3龄幼虫的拒食活性。结果表明,溴氰虫酰胺和氯虫苯甲酰胺均无杀卵作用,但能降低初孵幼虫存活率。溴氰虫酰胺对甜菜夜蛾、玉米螟和小地老虎3龄幼虫的LC₅₀值分别为0.11、0.05和0.13 mg/L,相对毒力分别是氯虫苯甲酰胺的2.8、2.7和5.1倍。溴氰虫酰胺对3种害虫成虫的LC₅₀值分别为0.11、0.09和0.22 mg/L,相对毒力分别是氯虫苯甲酰胺的3.9、3.8和2.7倍。溴氰虫酰胺在亚致死浓度0.10、0.05和0.14 mg/L的剂量下分别对甜菜夜蛾、玉米螟和小地老虎3龄幼虫表现出较强的拒食作用,处理48 h后达到最高,拒食率分别为85.58%、81.91%和86.11%。药剂处理试虫虫体皱缩,体节缩短,体重增加率明显低于对照处理。表明溴氰虫酰胺对3种鳞翅目害虫的毒力作用比氯虫苯甲酰胺好,可作为氯虫苯甲酰胺的替代药品。     

两株棒束孢菌的鉴定及其对茶卷叶蛾和茶小卷叶蛾的致病力

为明确分离自茶卷叶蛾和中华大刀螳僵虫的2株虫生真菌的归属及生防潜力,采用形态学特征和rDNA-ITS序列分析其分类地位,测定了其对茶卷叶蛾和茶小卷叶蛾幼虫的致病力,并初步筛选了其最适培养条件.结果表明:2株真菌均为环链棒束孢Isaria cateniannulata,分别命名为ICBS918和ICTL911.在1.0×10⁸孢子/mL浓度下,ICBS918和ICTL911对茶卷叶蛾幼虫的累计校正死亡率均达100%,LT₅₀分别为3.13 d和3.15 d;对茶小卷叶蛾幼虫的累计校正死亡率分别为100%和95%,LT₅₀分别为3.25 d和3.31 d.接菌后8 d,2菌株对茶卷叶蛾幼虫的LC₅₀分别为0.47×10⁵孢子/mL和1.01×10⁵孢子/mL;对茶小卷叶蛾幼虫的LC₅₀分别为2.20×10⁵孢子/mL和1.34×10⁵孢子/mL.2菌株23 ℃下最适生长培养基均为综合马铃薯培养基,最适产孢培养基均为蛋白胨马铃薯葡萄糖琼脂培养基;在萨氏培养基上,菌株ICBS918和ICTL911分别在24~30 ℃及24 ℃时生长速度最快,在27 ℃和21 ℃时产孢量最大.表明2株环链棒束孢对茶卷叶蛾和茶小卷叶蛾幼虫均具有较好的生防潜力,可作为生防菌进行开发和应用.     

健康和虫害菜豆对二斑叶螨、西花蓟马发育及繁殖的影响

为明确西花蓟马Frankliniella occidentalis （Pergande）和二斑叶螨Tetranychus urticae Koch取食的菜豆对后取食昆虫的影响,研究了二斑叶螨和西花蓟马分别取食健康和虫（螨）害菜豆时生长发育和繁殖情况,并组建生命表,比较生命参数的异同。二斑叶螨取食健康菜豆和西花蓟马2龄若虫为害菜豆时未成熟期没有明显区别,但各螨态的存活率在健康菜豆上较高;取食健康菜豆时,雌成螨寿命为24.56 d,内禀增长率为0.2640,均高于取食西花蓟马为害菜豆。西花蓟马的未成熟期取食两种菜豆时也没有明显的区别,但二斑叶螨为害菜豆使西花蓟马的存活率下降;西花蓟马雌成虫平均寿命和单雌日产卵量在健康菜豆上分别为33.35 d和4.02粒,显著高于螨害菜豆,在健康菜豆上净增殖率也较高,为40.4264。研究表明,西花蓟马或二斑叶螨为害后的叶片对后取食害虫的生长发育影响不大,但对其存活率和繁殖均产生不利影响,西花蓟马和二斑叶螨取食诱导菜豆产生了一定的防御反应。     

Biological and biochemical responses of Biomphalaria alexandrina to some extracts of the plants Solanum siniacum and Artemisia judaica L.

The molluscicidal activity of cold water, boiled water, methanol, ethanol, acetone and chloroform extracts of Solanum siniacum and Artemisia judaica L. plants against Biomphalaria alexandrina snails was carried out. The tests revealed plant’s ethanol extract was more toxic to the snails than the other tested extracts. Therefore, it was tested against snails’ fecundity (M_x), reproduction rate (R₀) and their infection with Schistosoma mansoni miracidia. In addition, biochemical parameters and the activities of some enzymes in tissues of snails treated with the two tested plants were determined. As well, glucose concentration in snails’ hemolymph was evaluated. Exposure of B. alexandrina snails to plant’s ethanol extract led to a significant reduction in their survival and snails’ fecundity, reproduction rate. In addition, it caused a considerable reduction in the infectivity of S. mansoni miracidia to the snails. Also, it caused a reduction in number of cercariae per snail during the patent period and in the period of cercarial shedding. The results revealed that the glucose concentration in hemolymph and Lactate level in soft tissues of treated snails were increased (P < 0.001) while glycogen, total protein, the lipid content and the pyruvate level in snail’s tissues decreased (P < 0.001). The activities of lactic dehydrogenase (LDH), pyruvatekinase (PK) and cytochrome oxidase (CY) enzymes in homogenate of snail’s tissues were reduced (P < 0.001) in response to treatment with the two tested plants while protease (PR) activity increased (P < 0.001). It is concluded that the application of LC₂₅ of ethanol extract of S. siniacum and A. judaica L. may be helpful in snail control as it interferes with the snails’ biology and physiology.     

Effects of a lectin-like protein isolated from Acacia farnesiana seeds on phytopathogenic bacterial strains and root-knot nematode

Acacia farnesiana lectin-like protein (AFAL) showed bacterioestatic effects against Xanthomonas axonopodis pv. passiflorae (Gram-negative) and Clavibacter michiganensis michiganensis (Gram-positive), with the latter being more sensitive. This effect is probably due to the ability of AFAL to interact with the bacterial cell wall where we observed that AFAL induced macroscopic change. The maximum bacterial growth inhibition was approximately 78% when incubated with Gram-negative strains, and as high as 92% percent for the Gram-positive one. The antibacterial effect of flavonoids (rutin, quercetin and morin) was also observed using low concentrations against both bacterial strains. Prior incubation of both with AFAL at high concentrations increases the inhibitory effect of flavonoids on bacterial growth. The potential use of AFAL as a control agent against the root-knot nematode Meloidogyne incognita was investigated as well, showing anti-nematode properties involving both egg hatching and motility. In the juvenile second-stage, AFAL showed reduction in larval mobility when measured against a control group. The results suggest that AFAL is effective against M. incognita and could be used as a component of integrated pest management programs. These data also suggest that lectins probably play a role in plant defense not only against invertebrate phytopathogens, herbivores and fungi but also against bacteria.     

Assessment of Cyfluthrin commercial formulation on growth, photosynthesis and catalase activity of green algae

Aquatic environments of the pampasic region of Argentina are severely affected by agricultural contamination due to an increase in a glyphosate tolerant transgenic variety of soybean crops. The present study is aimed to determine the effects of a commonly used Cyfluthrin commercial formulation (CCF) on growth, some physiological and biochemical parameter of four species of green algae. Significant inhibition of algal growth was observed from 0.1 mg Cyf/l. 96 h IC₅₀ were between 0.92 and 4.85 mg Cyf/l. CCF caused algicidal effects. Photosynthesis was stimulated by 50% in Scenedesmus quadricauda cultures exposed to the lowest concentration (hormesis). Algal photosynthesis inhibition was observed at higher concentrations with IC₅₀ values between 1.7 and 8.9 mg Cyf/l. Similar toxicity endpoints were found as a consequence of applying the traditional methodology of short-term chronic toxicity test of 96 h of exposition and the methodology developed using the Clark type photosynthetic oxygen evolution method. CAT activity was significantly increased between 23% and 33% considering the four species, at a lower concentration than those affecting algal growth and photosynthesis, indicating a potential biomarker. Taking into account that the extent of the soybean crops in the region is about fourteen million hectares, the improvement and extension of environmental tools for early detection of the action of pesticides on this essential group of organisms are discussed.     

苏云金杆菌亚致死浓度对美国白蛾及其寄生蜂生长发育的影响

为阐明苏云金杆菌Bacillus thuringiensis(Bt)与白蛾周氏啮小蜂Chouioia cunea Yang的协同作用,分别用103~108孢子/m L的6个Bt浓度处理美国白蛾Hyphantria cunea 2龄幼虫后,通过室内试验测定了Bt对其致死、亚致死效应,及亚致死浓度Bt对寄生蜂子代出蜂的影响。结果表明,浓度106孢子/m L处理组美国白蛾均未能化蛹;而106孢子/m L处理组均能化蛹并羽化,且幼虫发育历期随Bt浓度的增加而延长,平均蛹重在74.92~92.18 mg之间,均高于对照的68.66 mg,但蛹重不呈线性规律变化。当Bt对美国白蛾平均校正死亡率低于17.17%时,幼虫发育历期延迟不明显,但平均蛹重为101.11~124.34 mg,均高于对照;接蜂后能够正常出蜂,出蜂率为33.13%~51.25%,每蛹出蜂量为117.43~143.42头,均显著高于对照。表明用平均校正死亡率低于20%的Bt处理对白蛾周氏啮小蜂的寄生有利,2种生防措施协同作用存在增效潜力。     

枣镰翅小卷蛾成虫的寄主趋向和产卵选择

采用固相微萃取(SPME)和GC-MS分析研究木枣和酸枣挥发物成分,并测试枣镰翅小卷蛾触角电位(EAG)反应、寄主趋向和产卵选择,以探明枣镰翅小卷蛾的寄主选择机制。结果显示,在萌芽期,木枣和酸枣嫩叶的挥发成分均为罗勒烯、2-甲基-2-菠烯、α-法呢烯和邻苯二甲酸二丁酯4种,但相对含量稍有不同。枣镰翅小卷蛾成虫对木枣和酸枣2种寄主都有强烈的EAG反应,且同一寄主上雌蛾的EAG反应值极显著地高于雄蛾,其EAG值是雄蛾的3.3倍。枣镰翅小卷蛾对木枣表现强烈的趋向反应,而对酸枣的趋向不明显,且雌虫的趋向反应显著高于雄虫。木枣上的产卵量显著高于酸枣,且木枣枣吊上的单雌产卵量为307.9粒,极显著地高于酸枣枣吊上的产卵量(182.9粒)。研究表明,枣镰翅小卷蛾雌蛾在寄主选择中起主导作用,木枣是其嗜好寄主。