不同昆虫病原线虫一共生细菌组合的生化特性研究

本文分别以无菌的小卷蛾斯氏线虫的A24品系线虫与其自身携带的共生细菌菌株和与格氏线虫RS92品系的共生细菌菌株,以及以无菌的嗜菌异小杆线虫的H06品系线虫与其自身携带的共生细菌菌株和与大异小杆线虫HNA品系的共生细菌菌株建立单菌组合;测定了各组合感染期线虫的致病力、干重和体内主要生化物质的含量.结果发现,共生细菌除了对感染期线虫的致病力产生显著影响外,对线虫干重、蛋白质、氨基酸、糖原和脂肪酸等生化物质的含量也有很大的影响.     

芜菁夜蛾线虫和嗜菌异小杆线虫寄生特性的比较

对2种昆虫病原线虫(芫菁夜蛾线虫Steinernema feltiae Filipjev和嗜菌异小杆线虫Heterorhaditis bacteriphora Poinar)的生物学特性进行研究。结果表明:在25℃下,在大蜡螟Galleria mellonella L.幼虫体内完成1个侵染周期芫菁夜蛾线虫Otio品系需220～230h,嗜菌异小杆线虫15-2品系需200～210h。15-2品系比Otio品系具有较强的繁殖力。2种线虫侵染大蜡螟幼虫的温度范围均为20～30℃,在此温度范围内,Otio品系的侵染力和运动能力均强于15-2品系。当土壤含水量(w/w)为5%～15%,线虫的侵染活性最高,随湿度降低线虫的侵染活性明显降低。     

昆虫病原线虫(斯氏属与异小杆属)应用概况

<正> 在自然界,线虫与昆虫的联系是普遍的。据目前所知,至少有27个科的线虫与16个目近3000种昆虫有联系(Nickole 1984,Poinar 1983),其分布是由寄主昆虫的栖境所决定的。这些线虫对害虫的种群起着自然调节的作用。线虫与昆虫联系的方式各异,使人最感兴趣的是那些能作为害虫生物防治的病原线虫。自从Oldhan(1933)首次提出利用线虫防治害虫以来,应用病原线虫进行害虫生物防治的工作已     

昆虫病原线虫对腰果细蛾的致病力测定

室内测定了Steinernema carpocapsae All、S.carpocapsae Biosys、S.glaseri NC52、S.longicaudum X-7、Heterorhabditis bacteriophora H06和H.indica LN2共6个昆虫病原线虫品系对腰果细蛾Acrocercops syngramma Meyrick幼虫的致病力。结果表明,线虫S.carpocapsae All、Biosys品系与线虫S.glaseri NC52对腰果细蛾幼虫的致死效果显著高于其它线虫,但供试的6个线虫品系均未能在腰果细蛾幼虫体内繁殖下一代,说明供试线虫在腰果细蛾幼虫体内难以繁殖。选择小卷蛾斯氏线虫S.carpocapsae All进一步研究其对腰果细蛾的致病力,结果发现,All线虫对腰果细蛾3龄幼虫处理24 h后的致死中浓度LC50为19.88 IJs/虫。腰果细蛾各龄幼虫和蛹对小卷蛾斯氏线虫S.carpocapsae All均表现出高度的敏感性,但不同幼虫龄期和处理时间敏感程度不同。小卷蛾斯氏线虫S.carpocapsae All对不同龄期腰果细蛾幼虫和蛹均表现出较强的致病力。     

昆虫病原线虫防治草地贪夜蛾的研究进展

草地贪夜蛾Spodoptera frugiperda是一种重要的世界性害虫,目前已扩散至我国十余个省、市(区)。由于草地贪夜蛾已报道对多种常用农药及Bt等制剂产生抗性,因此寻求新的生防制剂具有重要的意义。昆虫病原线虫具有防治草地贪夜蛾的应用潜力。本文从昆虫病原线虫品系、保护剂、增效药剂、施用技术以及综合防控等方面综述了昆虫病原线虫防治草地贪夜蛾的研究进展,并对进一步开展应用昆虫病原线虫防治草地贪夜蛾的研究进行了展望。     

小卷蛾斯氏线虫侵染对草地贪夜蛾幼虫天然免疫反应的影响

【目的】探讨昆虫病原线虫小卷蛾斯氏线虫Steinernema carpocapsae All侵染对草地贪夜蛾Spodoptera frugiperda幼虫天然免疫反应的影响。【方法】借助倒置显微镜观察和鉴定草地贪夜蛾幼虫的血细胞类型,并对小卷蛾斯氏线虫侵染后不同时间的草地贪夜蛾幼虫血细胞总数目进行统计;通过倒置显微镜观察草地贪夜蛾幼虫对侵入的小卷蛾斯氏线虫的包囊反应;利用倒置荧光显微镜观察小卷蛾斯氏线虫侵染后的草地贪夜蛾幼虫血细胞对金黄色葡萄球菌Staphylococcus aureus的吞噬活性;检测小卷蛾斯氏线虫侵染后的草地贪夜蛾幼虫血淋巴中酚氧化酶(phenoloxidase, PO)活性、体内抗菌肽基因相对表达水平以及血浆的抗菌活性。【结果】从草地贪夜蛾幼虫体内共发现5种不同类型的血细胞,分别为原血细胞、粒细胞、类绛色细胞、珠血细胞和浆血细胞。注射1 μL侵染期(infective juveniles, IJs)小卷蛾斯氏线虫(3 IJs/μL)后9和12 h,草地贪夜蛾幼虫的血细胞总数目显著增多。草地贪夜蛾幼虫的血细胞不能包囊活的以及冷处死的小卷蛾斯氏线虫,但可以包囊热处死的线虫。活的小卷蛾斯氏线虫会显著抑制草地贪夜蛾幼虫血细胞对金黄色葡萄球菌的吞噬活性,但冷处死和热处死的线虫不能。注射1 μL(3 IJs/μL)小卷蛾斯氏线虫后,草地贪夜蛾幼虫血淋巴PO活性总体呈“下降 升高 下降”变化趋势;体内抗菌肽基因Attacin-A2, Attacin-B1, Cecropin-B3, Cecropin-D, Gallerimycin, Gloverin-3以及Lebocin-2的表达水平在线虫侵染后12 h时显著上调,24 h时恢复到对照水平或低于对照水平;血淋巴抗菌活性水平在小卷蛾斯氏线虫侵染后12 h时显著升高,24 h时与对照无显著差异。【结论】小卷蛾斯氏线虫在侵入早期会抑制草地贪夜蛾幼虫的天然免疫反应来建立感染;随后草地贪夜蛾的免疫系统会被激活试图抵御小卷蛾斯氏线虫的侵染;后期随着线虫的成功定殖,草地贪夜蛾的免疫系统最终被抑制或破坏。本研究所得结果为进一步揭示线虫 草地贪夜蛾的免疫互作机理奠定了基础,也为改善昆虫病原线虫对草地贪夜蛾的防治效果提供了理论依据。     

昆虫病原线虫斯氏线虫和异小杆线虫对长角血蜱雌蜱的致病力

用昆虫病原线虫小卷蛾斯氏线虫（Sc BJ）、夜蛾斯氏线虫（Sf Otio）、拟双角斯氏线虫（Sc D43）、格氏斯氏线虫（Sg NC32）和嗜菌异小杆线虫（Hb E-6-7）对长角血蜱雌蜱进行感染试验,所用线虫剂量为4 000 Ijs/dish。结果表明,5种线虫均对长角血蜱雌蜱有致死效应。Hb E-6-7和Sc BJ两种线虫对雌蜱各发育期致病力最强,导致雌蜱的累积死亡率和半致死时间分别为饥饿雌蜱82.5%,9.0天和75.0%,8.8天;吸血雌蜱90.0%,8.0天和82.5%,8.0天;饱血雌蜱93.3%,7.3天和86.7%,7.3天。Sc D43对饱血雌蜱有较高的致死效应,为80.0%,但半致死时间较长,为11.7天。Sf Otio和Sg NC32对长角血蜱雌蜱的致死效应较低。饱血雌蜱较饥饿雌蜱和吸血雌蜱更易被线虫感染。     

昆虫病原线虫与其共生细菌共生关系的研究进展

昆虫病原斯氏和异小杆线虫与共生细菌的共生关系是这类线虫作为害虫生物防治因子的基础。从线虫共生细菌的信息、营养、抗菌和病原作用,以及线虫对共生细菌的保护和媒介作用综述昆虫病原线虫与其共生细菌的共生关系;描述这一共生关系的影响因子;同时,讨论了未来的研究方向和应用前景。     

脱水休眠小卷蛾斯氏线虫的超微结构

采用扫描电镜,透视电镜和光学显微镜,对在SB高渗液中脱水体眠的小卷蛾斯氏线虫（Steinernema carpocapsae)BJ品系首次进行表态特征观察,结果表明：未脱水处理线虫体表光滑,侧线呈直线状,脱水体眠线虫体躯体稍弯曲,体表出现排列整剂的横向皱纹,侧线弯曲成有规律垢波浪状,脱水体眠后,线虫体长,体宽的明显减小达到了一个稳定值,比未处理线虫分别减少了33．1％和28．4％,脱水休眠线虫皮层和基质层变薄,皮下肌肉层明显变厚,肌肉纤维变形,排列没有方向性,食道与细胞器收缩,单位体积脂肪粒增多,以上这些变化可作为衡量小卷蛾氏线虫进入眠的形态特征参数。     

昆虫病原线虫感染寄主行为研究进展

昆虫病原线虫斯氏属Steinernema和异小杆属Heterorhabditids线虫是新型的生物杀虫剂。其感染期幼虫是惟一能够侵染寄主昆虫的虫态。这类线虫感染寄主的行为分为寻找寄主、识别寄主和侵染寄主。文章综述昆虫病原线虫感染寄主昆虫的行为以及在感染寄主过程中的影响因素。     

土壤含水量对桔小实蝇蛹期存活的影响

浸水时间、土壤含水量对桔小实蝇Bactroceradorsalis(Hendel)蛹的存活及成虫羽化的影响的研究结果表明:(1)不同浸水时间对桔小实蝇蛹存活率的影响不同。浸水时间越长,蛹存活率越低;浸水对初期蛹的影响较大,蛹龄越大,浸水作用效果越低。浸水时间(TW)、蛹期(AP)和蛹存活率(SP)之间关系符合以下模型:SP=0.4165-0.00307TW+0.2290AP-0.00004496T2W-0.0002528A2P+0.00008258TWAP。(2)土壤含水量对桔小实蝇成虫羽化影响明显。当土壤含水量较低或较高时,羽化率都明显受到抑制。相对含水量在30%～80%之间,蛹的羽化率较高。相对含水量(Ws)和成虫羽化率(E)之间存在以下关系:E=0.396+0.01985W-0.000181W2。     

桔小实蝇生物学特点及其防治研究概述

桔小实蝇Bactrocera(Bactrocera)dorsalis(Hendel)是危害热带、亚热带水果的重要检疫性害虫之一,本文综述了桔小实蝇主要生物学、生态学特点和防治措施的研究进展,包括桔小实蝇在国内的总体分布情况,对寄主的选择差异,各虫态的形态特征、发育历期和不同因子对其生长发育的影响,生活史以及农业防治、化学农药防治、诱杀防治、生物防治、物理防治等不同防治方法的研究和应用情况,并对今后的研究提出一些建议。     

桔小实蝇国内研究概况

本综述了桔小实蝇的研究概况,包括桔小实蝇的分布、寄主、为害情况、种类、生物学、生态学、生理生化、经济重要性评价、综合防治等方面。     

橘小实蝇交配行为观察

在实验室内对橘小实蝇Bactrocera dorsalis（Hendel）的交配行为进行了观察。描述了橘小实蝇交配中雄虫的“求偶场”,雄雄相遇、雌雌相遇、雌雄相遇时的相互反应,雌雄虫的交配行为与交配后行为。     

桔小实蝇生物学特性

桔小实蝇是一种重要的检疫性果蔬害虫,在厦门一年发生5-6代,以成虫越冬,一年8-10月份为发生高蜂期。本文记述了该虫的形态特征、年生活史、发育历期、发育起点温度,有效积温,生活习性及天敌等。     

Pathogenicity of three entomopathogenic nematodes against the onion thrips,Thrips tabaci Lind. (Thys.; Thripidae)

Pathogenicity of a native isolate of Steinernema feltiae (H1) and two exotic strains, Heterorhabditis bacteriophora and Steinernema carpocapsae was assessed under laboratory conditions using different concentrations i.e. 4000, 6000, 8000 and 10,000 infective juveniles/ml against second instar larvae, prepupa and pupa of Thrips tabaci Lindeman. The mortality data were recorded 24 and 48?h post-inoculation. The highest mortality rate was recorded for prepupa (62%) than second instar (12.5%) by H. bacteriophora and S. carpocapsae, respectively, 24?h after treatment. No significant differences were found in mortality between prepupa and pupa with increasing the nematodes concentrations (from 4000 to 10,000 nematode/ml) but increasing nematode concentrations increased the mortality of second instar. At the end of the experiment (48?h.), S. feltiae H1 caused the highest mortality on second instar larvae (74%), whereas all other species caused 80–83% mortalities on pupa. This study suggests that native isolate of S. feltiae (H1) had high potential to infect soil-dwelling stages of T. tabaci.     

三种常见实蝇的形态学、生物学和生态学比较

对瓜实蝇Bactrocera (Tetradacus) minax (Enderlein)、桔小实蝇Bactrocera (Bactrocera) dorsalis (Hendel)和桔大实蝇Bactrocera (Zeugodacus) cucurbitae (Coquillett)的形态学、生物学、生态学等方面进行了比较和分析,包括三种实蝇在国内外的分布情况,对寄主选择的差异,各种虫态的形态特征,发育历期和生活史,并对它们的危害状况和防治方法分别作了介绍,可为3种实蝇的鉴定和防治提供参考.     

Pathogenicity,reproduction and foraging behaviours of some entomopathogenic nematodes on a new turf pest,Dorcadion pseudopreissi (Coleoptera: Cerambycidae)

Entomopathogenic nematodes (EPNs) in the families Heterorhabditidae and Steinernematidae have considerable potential as biological control agents of soil-inhabiting insect pests. In the present study, the control potential of the EPNs Steinernema carpocapsae (TUR-S4), S. feltiae (Nemaplus), S. carpocapsae (Nemastar), S. feltiae (TUR-S3) and Heterorhabditis bacteriophora (Nematop) against a new longicorn pest, Dorcadion pseudopreissi Breuning, 1962 (Coleoptera: Cerambycidae), on turf was examined in laboratory studies. Pathogenicity tests were performed at the following doses: 50, 100 and 150 Dauer Juveniles (DJs)/larva at 25°C. Highest mortalities (75–92%) of the larvae were detected at the dose of 150 DJs/larva for all nematodes used. Reproduction capabilities of the used EPNs were examined at doses of 50, 75, 100 and 150 DJs/larva at 25°C. S. carpocapsae (TUR-S4) had the most invasions (32 DJs/larva) and reproduction (28042 DJs/larva) at the dose of 100 DJs, and the highest reproduction (per invaded DJ into a larva) was observed in H. bacteriophora (Nematop) (2402.85 DJs) at a dose of 50 DJs. The foraging behaviour of the nematodes in the presence of D. pseudopreissi and Galleria mellonella L. (Lepidoptera: Galleriidae) larvae was studied using a Petri dish filled with sand at 20°C. All of the used nematodes accumulated near the larvae section of both insect species (32–53% of recovered DJs) with a higher percentage of S. carpocapsae (TUR-S4) (53%) and H. bacteriophora (48%) (Nematop) moving towards larvae of D. pseudopreissi, than the S. feltiae strains.     

Field efficacy of entomopathogenic nematodes against the beetle Maladera matrida (Coleoptera: Scarabaeidae)

Single, double and triple releases of the entomopathogenic nematode Heterorhabditis bacteriophora Poinar, reduced the population of the beetle Maladera matrida Argaman, infesting peanuts (’Shulamit’ cv.) by 70, 75 and 93% respectively in microplot tests. Simultaneous and late (2 weeks after infestation) applications reduced beetle numbers by 63 and 79% respectively, in the microplots, while early application (2 weeks prior to infestation) did not reduce the beetle population. In a field trial, reductions in insect population and damage to the crop were achieved by early treatment with the nematode as well as by Heptachlor, leading to reductions in the insect population of 60 and 90% respectively, when recorded 4 weeks after nematode application. However, the nematode treatment did not maintain its effectiveness for a longer period and pest damage increased to the same level as the untreated control after 7 weeks. When the nematodes were applied at different concentrations (0.25–1.0 x 10⁶ infective juveniles (IJs) m^‐2) their effectiveness was not related to the concentration level. The only significant (P < 0.05) reduction in insect levels was recorded in the treatment with 0.5 X 10⁶ IJs m^‐2. In a second field trial, both H. bacteriophora and Steinernema glaseri reduced insect populations significantly (P < 0.05) by approximately 50% in comparison to the control. In the third trial, treatment with H. bacteriophora resulted in a decrease in insect population of 90% while treatment with S. carpocapsae reduced the grub numbers by 40% in comparison to the control. A differential susceptibility of various grub developmental stages was recorded in the field. The small grubs (I‐4 mm long, lst‐2nd larval stage) were not affected by the nematode treatments while the numbers of medium and large size grubs were reduced by 2‐ and 3‐fold respectively in the various tests. Nematodes were recovered by ‘nematode traps’ containing Galleria mellonella larvae from treated field plots 78 days after application. The implications of the results from the present studies on the use of entomopathogenic nematodes are discussed in relation to the development of an integrated pest management programme.     

Behavioural response of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora to oxamyl

Infective juveniles of the entomopathogenic nematode Steinernema carpocapsae show a low level of locomotory activity that is presumed to limit their usefulness as biological insecticides. A 30 μg ml^-1 solution of the carbamate pesticide oxamyl reduced the proportion of nonmobile nematodes by nearly two thirds to 35%, while stimulating a 7.5-fold increase in sinusoidal movement. This increase in activity did not result in a corresponding increase in host-finding. Oxamyl treatment did not enhance infective juvenile pathogenicity to Galleria mellonella larvae. At higher concentrations, oxamyl caused aberrant nematode movement and partial paralysis. Heterorhabditis bacteriophora infective juveniles maintain a high level of locomotory activity. Treatment with 30 μg ml^-1 oxamyl increased the proportion of sinusoidal over nonsinusoidal movements, but infective juvenile host-finding and pathogenicity were significantly reduced. Higher rates impaired movement and induced complete paralysis. We conclude that oxamyl is incompatible with S. carpocapsae and H. bacteriophora. The concept of chemically activating infective juveniles to increased locomotory activity and thereby achieving enhanced efficacy is inconsistent with our results.