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1.
Entomopathogenic nematodes (EPNs) are agents that can be used for the biological control of pests associated with pesticides in a tank mix. Compatibility studies need to be conducted to analyse which products are compatible with EPNs. The survival of infective juveniles (IJs) of four species of EPNs (Steinernema, Heterorhabditis) was determined after exposure to eight chemical herbicides. The effect of direct IJs exposure to herbicides for 1, 4 and 24 h was tested in a Petri dish at 15, 20 and 25 °C. The study showed that Steinernema kraussei was the most tolerant among the tested EPN species, while S. carpocapsae was the most sensitive to all tested herbicides. The lowest mortality of IJs was at 15 °C (19%). Our investigation showed, overall, the herbicides negatively affected EPN survival. The results confirmed that the compatibility is a species-specific characteristic, influenced by the temperature and time of exposure. Application of two different control ingredients (insecticide and herbicide) at the same time would reduce cost and time consumption in pest/weed control.  相似文献   

2.
A total of 27 entomopathogenic nematode (EPN) strains originally isolated from different cotton fields were characterized in laboratory experiments for their virulence, reproductive potential and environmental tolerance. The EPN strain collections included 16 Steinernema carpocapsae (SC), three Steinernema siamkayai (SS), one Steinernema monticolum (SM), and seven Heterorhabditis bacteriophora (HB). Their virulence was tested against cotton bollworms such as the American bollworm Helicoverpa armigera, the spotted bollworm Earias vittella and the cotton leafworm Spodoptera litura. Larvae of H. armigera, E. vittella and S. litura were susceptible to all the tested EPN species/strains with significant differences among EPN species/strains. The most virulent strains were APKS2 (SC), TRYH1 (HB) KKMH1 (HB) and KKMH2 (HB) on H. armigera (91.9–93.5% mortality); KKMS1 (SC), APKS2 (SC), TRYH1 (HB), KKMH1 (HB), KKMH2 (HB) and APKH1 (HB) on E. vittella (92.7% mortality); and APKS2, TRYH1, KKMH1, KKMH2 and KKMH3 on S. litura (92.7% mortality). The results of the invasion rate assay indicated that the EPN strains more virulent against the target host had greater invasion rates. In the multiplication assay, KKMH1and OCMS1 (SC) produced a greater number of infective juveniles (IJs) (32.1–32.4 x 1000 IJs/ cadaver) in Carcyra cephalonica. Test for tolerance to heat at 40°C for 2 h revealed that KKMH1, TRYH1, KKMH2, KKMS1 and APKS2 were highly tolerant (>85% survival). IJs exposed to ambient room conditions (27–29°C; 65–70% r.h.) for 2 h showed that APKS2, OCMS1 and KKMS1 were more tolerant (68–69% survival) of rapid desiccation than others. APKS2, KKMS1 and KKMH1 showed better survival (70–73%) in slow desiccation assay when exposed to 25°C with 97% r.h. for 72 h, followed by 25°C with 93% r.h. for 48 h. The H. bacteriophora KKMH1 and S. carpocapsae APKS2 performed best in nine traits out of ten tested, followed by H. bacteriophora TRYH1, which performed best for six traits. It is suggested that the EPN strains KKMH1 and APKS2 could be deployed for a cotton bollworm management program after testing their performance under field conditions.  相似文献   

3.
The pathogenicity of steinernematid and heterorhabditid nematodes to caterpillars of the giant looper,Boarmia selenaria (Schiffermüller) (Lepidoptera: Geometridae), was determined under laboratory conditions. High mortality (over 80%) was achieved, in a petri dish bioassay, with a minimum of 20,000 infective juveniles (IJ) ofSteinernema carpocapsae (Filipjev) (=Neoaplectana carpocapsae Weiser), strain ‘All’. The LD50 was 4250 IJ per caterpillar. Similar results were obtained withS. carpocapsae, strain ‘Mexican’,Steinernema sp., strain ‘CR’;Heterorhabditis bacteriophora, strain ‘HP88’; andHeterorhabditis sp., strain ‘IS’. The first and second instars were the most susceptible stages to nematode infection. A laboratory model assay indicated that 80–90% of the caterpillars were killed when they migrated to the soil to pupate; this occurred when IJ were applied to sandy and heavy soils at a concentration of 400 IJ/cm3 soil. A greenhouse test reconfirmed the effectiveness of utilizing the entomopathogenic nematodes in an “ambush” system against caterpillars migrating to the soil.  相似文献   

4.
两种昆虫病原线虫防治核桃云斑天牛田间效果评价   总被引:1,自引:0,他引:1       下载免费PDF全文
云斑天牛Batocera lineolata Chevrolat是核桃树的严重蛀干害虫,隐蔽性强,化学、物理防治方法难以奏效,昆虫病原线虫可以主动寻找寄主并在蛀道内建立种群,省工长效。本研究评价了不同剂量(250、500、1000、2000和4000 IJs/mL)的2种昆虫病原线虫(小卷蛾斯氏线虫Steinernema carpocapsae和嗜菌异小杆线虫Heterorhabditis bacteriophora)对核桃云斑天牛卵和幼虫的防治效果。结果表明,2种线虫对天牛卵和幼虫的最终防控效果随施用剂量增大而增强。施用剂量为4000 IJs/mL的小卷蛾斯氏线虫和嗜菌异小杆线虫对该天牛卵的校正防治效率分别达65.0%和39.5%,对幼虫的最终校正防治效率分别达93.8%和82.4%;2种线虫在2000 IJs/mL剂量下对天牛卵的校正防治效率分别达48.8%和32.3%,对幼虫的校正防治效率分别达85.9%和83.4%。从而说明,适宜剂量的昆虫病原线虫对云斑天牛幼虫的田间防控效果好于对卵的效果,可以作为云斑天牛的有效防治技术。  相似文献   

5.
Entomopathogenic nematodes (EPNs) from the genus Steinernema (Steinernematidae) are used for biological control of insect pests. The infective stages of these nematodes are intolerant of extreme environmental conditions. Genetic improvement has been suggested as an approach for improving their ability to overcome these limitations. In this study, we bred a heterogeneous population of the EPN Steinernema feltiae Filipjev for desiccation tolerance (both rapid and slow) and enhanced host-seeking ability. We selected for tolerance of rapid desiccation by exposing infective juveniles (IJs) to ambient conditions (22–25°C; 50–65% r.h.) for 100 min. A survival rate of 80–90% was reached after ten selection cycles. To select for tolerance of slow desiccation, we exposed IJs to 97% r.h. for 72 h, followed by further exposure to 85% r.h. for an additional 72 h. A high survival rate (>85%) was obtained after 20 selection cycles. We selected for enhanced downward dispersal by forcing IJs to move through a sand column to reach larvae of last-instar Galleria mellonella placed at the bottom of the column. After 25 selection cycles, the majority (>75%) of these nematodes were found at the layer close to the insects. No reduction in fitness was detected in the selected populations. Nevertheless, the nematode population selected for enhanced downward dispersal displayed significantly higher infectivity than the foundation population. The population selected for slow desiccation was more tolerant of heat stress than the foundation population. These findings establish the basis for improvement of this nematode for use as a biological control agent under field conditions.  相似文献   

6.
昆虫病原线虫对小地老虎的致病力测定及防治效果   总被引:1,自引:0,他引:1  
为探讨应用昆虫病原线虫防治小地老虎技术的可行性,采用培养皿滤纸法比较9个品系的昆虫病原线虫对小地老虎幼虫的致病力,同时通过盆栽试验验证了斯氏线虫属小卷蛾斯氏线虫Steinernema carpocapsae NC116品系、芫菁夜蛾斯氏线虫S.feltiae SF-SN品系和异小杆线虫属嗜菌异小杆线虫Heterorhabditis bacteriphora H06品系的保苗效果和防治效果,并测定了苦参碱与NC116品系混用对小地老虎3龄幼虫的联合作用效果。结果表明,NC116品系对小地老虎3龄幼虫致病力最高,其对3龄、4龄和5龄的LD50分别为2.4、7.5、和31.2条/头,表明随小地老虎幼虫龄期递增,其致病力下降。盆栽玉米苗上分别施用线虫100~200条/头时,对玉米保苗效果及对小地老虎3龄幼虫的控制效果依次为NC116H06SF-SN。0.8 mg/L苦参碱和NC116品系混用后,可使小地老虎3龄幼虫死亡率提高109.89%,二者表现增效作用。  相似文献   

7.
Abstract

The pine tree lappet moth Dendrolimus pini (Lasiocampidae) is one of the most dangerous pests of pine Pinus sylvestris stands in Central Europe. To develop biological control method of this pest, the bioassay was made to assess the sensitivity of D. pini caterpillars to native EPMs strains representing two species: Steinernema feltiae and Heterorhabditis megidis in laboratory conditions. The results showed higher activity of S. feltiae strains which parasitized 86.7 - 100% of D. pini caterpillars, compared to the 20-100% of insects parasitized by H. megidis strain. Most nematodes were found in caterpillars treated with S. feltiae (in average 40 IJs/caterpillar), the least – in individuals parasitized by H. megidis (in average IJs/caterpillar). No effect of dose and temperature on parasitizm was found with S. feltiae strains while in H. megidis increased doses resulted in higher extensity of parasitism. The results indicate higher biological activity of S. feltiae strains and advisability of their further studies in field experiments.  相似文献   

8.
The potential use of steinernematid and heterorhabditid nematodes against the beetleMaladera matrida Argaman (Coleoptera: Scarabaeidae) was determined under laboratory and greenhouse conditions. Infective juveniles (IJ’s) of the nematodeHeterorhabditis sp., Hp88 strain, mixed with soil at a concentration as low as 50 IJ’s/cm3 soil, resulted in 86% control. No increase in control was obtained with higher nematode concentrations. Soil surface application of the nematodes at concentrations of 160 and 640 IJ’s/cm2 was sufficient to obtain 87% and 86% mortality, respectively, even at a depth of 40 cm below the soil surface. TheHeterorhabditis sp. Hp88 strain was found to be the most pathogenic to the beetle grubs at 25°C. Lower control levels of 30-47% were achieved byHeterorhabditis sp. HL81 strain,S. feltiae ‘All’ strain and 5.bibionis CR strain. The nematodeHeterorhabditis sp. BS strain did not have any effect on insect mortality. However, at a temperature of 16°C, the HL81 strain ofHeterorhabditis sp. was the most effective. Grubs 3-5 wk old were found to be the most susceptible developmental stage of infection ofHeterorhabditis sp. Hp88 strain. Pupae, which were exposed to the nematodes in the same experimental regime, were not affected. The results obtained in the present study suggest thatM. matrida is an attractive candidate for biological control by entomoparasitic nematodes.  相似文献   

9.
昆虫病原线虫对甘薯蚁象的致病力测定   总被引:2,自引:0,他引:2  
昆虫病原线虫是隐蔽性害虫的有效生物防治因子,对8种斯氏线虫和3种异小杆线虫进行筛选证实夜蛾斯氏线虫Steinernema feltiae对甘薯蚁象Cylas formicarius的致病力最强;在此基础上进一步研究了11个不同地理来源的S.feltiae品系对甘薯蚁象末龄幼虫的致病力,获得强致病力的品系S.feltiae JY-17并测定了不同因素对该线虫品系致病力的影响。研究结果表明:在25℃条件下,甘薯蚁象不同发育阶段对S.feltiae JY-17的敏感性依次为末龄幼虫〉低龄幼虫〉蛹〉预蛹期〉成虫;在不同测试温度条件下,sfeltiae JY-17致病力由高到低顺序为25℃〉20℃〉30℃〉15℃〉10℃〉35℃;在25℃条件下,当寄主密度为196.6头·m^-2时,线虫对蚁象末龄幼虫的LD50=5.532条·头^-1,LD90=28.049条·头^-1;当线虫与寄主比例为5:1时,LT50=44.306h。本研究为利用昆虫病原线虫防治甘薯蚁象提供了理论依据。  相似文献   

10.
The date stone beetle,Coccotrypes dactyliperda F. (Coleoptera: Scolytidae), is a primary pest of green unripe dates. The adult beetle chews a characteristically round hole in the fruit, which results in the druit dropping 1 or 2 days later. Egglaying and entire development occur within galleries produced by the female in the date stone; males are unable to penetrate the stones. In laboratory cultures and in field-collected date stones, the beetle adult females were predominant (85-93%). Overwintering probably occurs in the adult stage within date stones of fruits which had dropped and were left on the ground. At 28°C the average egg incubation period was 5.9 days, larval duration 12–15 days, and pupal development 4.0 days. Development from egg to adult for females was significantly longer than for males (24.8vs. 22.1 days). Mated females produced males and females, whereas unmated females gave rise to males only. The mean number of progeny per mated female (30.4) was significantly higher than that recorded for unmated females (6.6), but the latter lived significantly longer (73.3vs. 62.9 days).  相似文献   

11.
Modes of passive dispersal of the grape rust mite Calepitrimerus vitis (Eriophyoidea) were investigated in a vineyard of South-Western Germany. More than 200 Eriophyoidea per month were trapped in a wind chamber during summer (32,1% C.vitis) suggesting long-distance dispersal by air currents. Rain washed part of the adult C.vitis population from the foliage. SE micrographs suggest that quiescent nymphs are affixed to the leaf by a substance of unknown nature. However, the role of rain in C.vitis colonisation of uninfested vineyards is still unclear, as is the role of phoretic transport by arthropods. For the first time, evidence of rust mite dispersal by human activity is presented. A large number of C.vitis was found adhering to clothes and hands of workers carrying out customary cultural practices in the vineyard. Other arthropods, including Typhlodromus pyri, the main predator of C.vitis, were also passively transported by wind, rain and human activity.  相似文献   

12.
EPN is twice as toxic as EPNO to house flies from both the Diazinon-resistant strain and the susceptible strain. EPN and EPNO are also eight times more toxic to the susceptible than the resistant strain. This is due to the ability of the resistant strain to metabolize these compounds to a greater extent. Metabolism by the glutathione S-transferases present in the 100,000g supernatant is more extensive than that by the NADPH-dependent microsomal mixed-function oxidases. The glutathione S-transferases are the major route of metabolism for EPN and appear to be the principal mechanism conferring resistance. EPN was metabolized by the microsomal fraction via oxidative desulfuration to the oxygen analog, EPNO, and by oxidative dearylation to p-nitrophenol. EPNO was metabolized by the same system to p-nitrophenol and desethyl EPNO as well as to an unknown metabolite. The soluble fraction metabolized EPN to p-nitrophenol, S-(p-nitrophenyl)glutathione, O-ethyl phenylphosphonothioic acid, and S-(O-ethyl phenylphosphonothionyl)glutathione. The identification of the latter conjugate demonstrates a new type of metabolite of organophosphorus compounds. EPNO was metabolized by the soluble fraction to p-nitrophenol and S-(p-nitrophenyl)glutathione.  相似文献   

13.
红脉穗螟Tirathaba rufivena Walker是槟榔上的重要害虫。本研究采用大蜡螟诱捕法,对海南省主要槟榔产区槟榔园中采集到的土样进行昆虫病原线虫的诱捕,并评估了目标线虫对红脉穗螟的致病力。在采集的150份土样中共有12个土样经检测发现含有昆虫病原线虫,检出率为8%。其中,屯昌、定安和万宁三个市县采集的土样中检出的带线虫比率相对较高,分别为12.90%、11.76%和10.00%,而海口和保亭土样中未检出昆虫病原线虫。在室内以大蜡螟为试虫测试线虫的致病力,结果表明诱捕的12个线虫种群均对大蜡螟幼虫具有一定的致病力,但致病力的大小存在较大差异(120 h校正死亡率21.11%~72.22%)。选取致病力较高的Tc05、Wn01和Wn09样本测试对红脉穗螟3龄幼虫的致病作用,结果显示在600 IJs/mL线虫液处理后24 h,Wn01种群对寄主的校正死亡率达到86.67%,半致死浓度LC50为283.70 IJs/mL;Tc05和Wn09对红脉穗螟的致病力相近,校正死亡率分别为61.67%和65.00%,LC50分别为504.75 IJs/mL和502.70 IJs/mL。研究表明,Wn01,Tc05和Wn09线虫种群对红脉穗螟幼虫具有一定的控制潜力。  相似文献   

14.
In Oman, the bark beetle Hypocryphalus mangiferae is closely associated with trees affected by mango sudden decline disease caused by Ceratocystis manginecans. Although it has previously been assumed that this beetle plays a role in the dispersal of the pathogen, this has not been established experimentally. The aim of this study was to determine whether H. mangiferae vectors C. manginecans from infected to healthy mango trees. A survey conducted in northern Al Batinah region of Oman revealed that H. mangiferae was closely associated with mango sudden decline disease symptoms and it was found on trees in the early stages of the disease. Healthy, 2-year-old mango seedlings were exposed to H. mangiferae collected from diseased mango trees. Seedlings were infested by the bark beetles and after 6 weeks, typical mango sudden decline disease symptoms were observed. Ceratocystis manginecans was isolated from the wilted mango seedlings while uncolonized control seedlings remained healthy. The results show that H. mangiferae vectors C. manginecans in Oman and is, therefore, an important factor in the epidemiology of this disease.  相似文献   

15.
The in vitro metabolism of EPN (O-ethyl O-p-nitrophenyl phenylphosphonothionate) and EPNO (O-ethyl O-p-nitrophenyl phenylphosphonate) in mouse liver was studied. EPNO was metabolized faster than EPN, and the highest metabolic activity was found in the 10,000g supernatant in the presence of both NADPH and glutathione. Liver microsomes in the presence of NADPH metabolize EPN to its oxygen analog, EPNO and p-nitrophenol. With the 100,000g supernatant only slight metabolism of EPN occurred in the presence of GSH. Metabolism of EPNO by liver microsomes increased upon the addition of NADPH. p-Nitrophenol was the only metabolite isolated in the presence of microsomes, whereas, with the addition of NADPH, both p-nitrophenol and desethyl EPNO were formed. Quantitative studies showed that there was little, if any, oxidative dearylation of EPNO by liver microsomes. The 100,000g supernatant was found to actively degrade EPNO, and this increased upon addition of glutathione. The initial rate of p-nitrophenol formation as a result of incubation of EPN and EPNO with liver microsomes was found to be higher with EPN than EPNO.  相似文献   

16.
Carbofuran and carbaryl LD50 values were determined with and without piperonyl butoxide pretreatment for a resistant (New Jersey) and two susceptible (Utah and Netherland) populations of Colorado potato beetle larvae. Similar bioassays were conducted with carbofuran for resistant (Rutgers) and susceptible (NAIDM) adult house flies. The degree of resistance development by New Jersey Colorado potato beetles (RR = 848) was greater than that of the laboratory-selected colony of Rutgers house flies (RR = 583). Comparisons of synergist difference calculations including “percentage synergism” (%S), “log percentage synergism” (L%S), and “relative percentage synergism (R%S) for the resistant (R) and the susceptible (S) populations indicated the possibility that monooxygenases and other resistance mechanisms may be involved in Colorado potato beetle resistance to these carbamates. Monooxygenase involvement in resistance of Rutgers house flies was demonstrated in vitro by a 4-fold enhancement of p-nitroanisole O-demethylation over that of NAIDM house flies. O-demethylation of p-nitroanisole could not be demonstrated for potato beetle larvae. Colorado potato beetle resistance was associated with increases in microsomal levels of NADPH-cytochrome c reductase (ca. 2-fold) and NADPH oxidation (1.2-fold). The inability to measure O-demethylation in Colorado potato beetles may have been due to the solubilization of NADPH-cytochrome c reductase during microsomal preparation. Significant differences between resistant and susceptible Colorado potato beetle larvae were not observed in the penetration of [14C]carbaryl. Excretion of the radiocarbon may have been significantly greater in the resistant New Jersey population, but some of the insecticide may have also rubbed off the cuticle. This increased capacity for excretion, combined with increased levels of monooxygenase enzymes, could account for the high resistance level of this population.  相似文献   

17.
The optical isomers of EPN (O-ethyl O-p-nitrophenyl phenylphosphonothionate) and EPNO (O-ethyl O-p-nitrophenyl phenylphosphonate) have been synthesized. No significant difference in the rate of alkaline hydrolysis of the isomers at the two pH's evaluated was observed. The (+)-isomers of EPN and EPNO were more toxic to house flies than the corresponding (?)-isomers, while the (+)- and (?)-isomers, as well as the racemic mixture of EPN, were almost equally toxic to mice. The (+)-EPNO is more toxic to mice than the corresponding (?)-isomer. Cholinesterase inhibition studies demonstrated that (+)-EPNO has a higher bimolecular rate constant, (ki) than the corresponding (?)-isomer. This higher inhibitory power was due to a higher affinity (Ka) of the (+)-isomer.  相似文献   

18.
The organophosphorus pesticides profenofos, sulprofos, O-ethyl O-(4-nitrophenyl) phenylphosphonothioate (EPN), and S,S,S,-tributyl phosphorotrithioate (DEF) administered intraperitoneally to mice at 0.5 to 5 mg/kg strongly inhibit the liver microsomal esterase(s) hydrolyzing trans-permethrin. Profenofos, EPN, and DEF at 25 mg/kg increase the intraperitoneal toxicity of fenvalerate > 25-fold and of malathion > 100-fold. Topically applied profenofos, sulprofos, and DEF significantly synergize the toxicity of cis-cypermethrin to cabbage looper larvae and house fly adults but these phosphorus compounds are much less effective in synergizing the toxicity of trans-permethrin. The magnitude of synergism appears to depend on the species, organophosphorus compound, and pyrethroid involved. Profenofos, sulprofos, and EPN do not significantly alter the persistence of trans-permethrin on bean foliage.  相似文献   

19.
椰心叶甲人工饲料的研制及应用效果评价   总被引:1,自引:0,他引:1  
为了获得入侵害虫椰心叶甲Brontispa longissima(Gestro)的人工饲料,在分析其天然寄主叶片水分和营养成分基础上,借鉴其它鞘翅目昆虫人工饲料配方,进行椰心叶甲人工饲料的配制和筛选,并评价人工饲料饲养的椰心叶甲对其寄生蜂椰甲截脉姬小蜂Asecodes hispinarum和椰心叶甲啮小蜂Tetrastichus brontispae的适合性。人工饲料配方的成分:蔗糖4%、椰子粉2%、大豆粉2%、椰树叶粉10%、酵母2%、维生素E 0.3%、抗坏血酸0.2%、对羟基苯甲酸甲酯0.2%、琼脂4%、链霉素0.03%和水75%。用所配制的人工饲料饲养椰心叶甲初孵幼虫,其蛹成活率可达36%,蛹羽化率与对照无显著差异,均在90%以上;雌成虫占52.4%,与对照无显著差异。表明人工饲料饲养所得的椰心叶甲可用于其幼虫寄生蜂椰甲截脉姬小蜂和蛹寄生蜂椰心叶甲啮小蜂的扩繁。  相似文献   

20.
The pine sawyer beetle Monochamus galloprovincialis (Olivier) (Coleoptera Cerambycidae) gained importance as a pest in Europe after the introduction in Portugal of the pine wood nematode Bursaphelenchus xylophilus, the agent of pine wilt disease. As the nematode is transmitted by the adult beetles during both maturation feeding and oviposition, effective methods of monitoring of the longhorn beetle populations are needed for the surveillance of the disease spread in Europe. Although in the last years many studies focused on the efficacy of different trapping methods, the general results are still controversial. In this study, we compared the efficiency of two trap types, cross-vane and multi-funnel, and two attractive blends, a kairomonal lure (??-pinene, ipsenol and methyl-butenol) and a commercial kit specific for M. galloprovincialis (pheromone plus kairomonal lure), in order to identify the trap/blend combination more appropriate for the surveillance of the M. galloprovincialis populations. Moreover, the trap efficiency was tested also in a pine stand colonized by M. galloprovincialis after a hailstorm and in a control stand. The results showed that the multi-funnel traps baited with the specific commercial kit was the most effective combination. Interestingly, trap catch was similar in the two pine stands, despite a different density of the target species. As the trapping method was effective also at low population density of M. galloprovincialis, it may be adopted as a general tool for beetle surveillance in the forest and at ports of entry.  相似文献   

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