昆虫病原线虫对小地老虎的致病力测定及防治效果

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。     

对铜绿丽金龟具有高致病力的昆虫病原线虫的筛选

为筛选对铜绿丽金龟Anomala corpulenta幼虫具有生防潜力的昆虫病原线虫品系, 测定了9个昆虫病原线虫品系对铜绿丽金龟1 龄幼虫的致病力, 以及不同施用剂量、环境温度及土壤相对湿度条件对线虫致病力的影响。生测结果表明, 樱桃异小杆线虫品系Heterorhabditis beicherriana D26-6对铜绿丽金龟幼虫致病力最高, 处理11 d后的校正死亡率达到了98.3%;对线虫D26-6致病力的单因子测定发现, 侵染铜绿丽金龟幼虫的最佳剂量为150 IJs/头、最佳温度范围为20~30℃、最佳土壤湿度为18%, 有较好的开发应用潜力。     

昆虫病原线虫对腰果云翅斑螟的室内致病力

研究了小卷蛾斯氏线虫Steinernema carpocapsae All品系、Biosys品系,格氏斯氏线虫S.glaseri NC52品系,长尾斯氏线虫S.longicaudum X-7品系,嗜菌异小杆线虫Heterorhabditis bacteriophora H06品系和印度异小杆线虫H.indica LN2品系6个昆虫病原线虫品系在室内对腰果云翅斑螟Nephopteryxsp.幼虫的致病力。结果表明,除了嗜菌异小杆线虫,其他参试线虫对腰果云翅斑螟3龄幼虫均具有较高的致病力,致死率80.0%~95.0%,各处理差异不显著。嗜菌异小杆线虫对腰果云翅斑螟幼虫控制效果最差,显著低于其他参试线虫。选择小卷蛾斯氏线虫All品系进一步研究其对腰果云翅斑螟的致病效果,结果发现,其对腰果云翅斑螟3龄幼虫处理24h后的LC50为22.94IJs/头。处理24h,小卷蛾斯氏线虫All品系对1~3龄幼虫的致死率(72.5%~84.7%)显著高于4~5龄幼虫(15.0%~30.0%);处理120h,对蛹的致死率仅为20.0%。研究表明,小卷蛾斯氏线虫All品系对腰果云翅斑螟低龄幼虫在室内具有一定控制潜力。     

利用昆虫病原线虫防治桃红颈天牛

1991～1992年在郑州进行了利用昆虫病原线虫防治桃红颈天牛(Aromia bungii Fald)幼虫的室内及田间试验。在室内条件下,用6个线虫种(品系)测定的结果,所有线虫对桃红颈天牛均有侵染力。以Steinernema bibionis Otio和S.feltiae Mexican对桃红颈天牛幼虫的侵染力较强,LT50分别为1.19天和1.40天,详见表1。     

昆虫病原线虫与黑色粘板配合使用对韭菜迟眼蕈蚊的防治

为探索昆虫病原线虫与色板配合使用对韭菜迟眼蕈蚊的综合防治技术,采用培养皿滤纸法比较7品系昆虫病原线虫对韭蛆3龄幼虫的致病力,盆栽法研究斯氏线虫属3品系线虫的保苗和防治效果;并通过温室和田间试验比较10种颜色粘板和3个粘板高度对迟眼蕈蚊成虫的诱集效果,研究线虫与黑色粘板配合使用对韭菜迟眼蕈蚊的防治效果。结果表明:SF-SN品系线虫对韭菜迟眼蕈蚊3龄幼虫致病力最高,LD50为60.0条/头,施用线虫剂量为200、400条/头时,其保苗和防治效果高低依次为SF-SN、All、NC116,其中施用SF-SN品系5 d,保苗效果达62.74%,防治效果达60.26%;黑色粘板诱集效果极显著高于其它色板,且下部(色板下缘离地面1 cm处)诱集成虫量最多,与中部(15 cm)、上部(30 cm)之间差异极显著。研究表明,SF-SN品系线虫主要用于防治幼虫,黑色粘板主要诱杀成虫,二者配合使用防治效果可达97.60%,能够极大地降低虫口基数。     

芜菁夜蛾线虫对小木蠹蛾侵染能力的研究

1988年室内试验结果证明:芜菁夜蛾线虫的5个品系Agriotos、All、Mexican、NC 116、Florida对蛀干害虫小木蠹蛾幼虫有很高的侵染力;但不侵染蛹。用Agriotos品系作试验,剂量和温度影响小木蠹蛾的死亡率和致死速度。当剂量大于25条线虫/木蠹蛾幼虫时,死亡率可达92％以上,同一剂量对一年、二年生幼虫的死亡率差异不显著。在15-30℃的范围内,线虫均能侵染和杀死寄主,但30℃不能在寄主尸体内繁殖。25℃为线虫浸染的最适宜温度,寄主死亡率最高,死亡速度也最快。一头5龄和7龄木蠹蛾幼虫能繁殖侵染期线虫16万和48万头。在10℃低温中,线虫不能侵染寄主,但并不死亡,当移入适宜的温度后,能迅速恢复活动。在35℃高温中,线虫则很快死亡。     

昆虫病原线虫JLSY 003的鉴定及其生物学特性测定

经28S rDNA和ITS序列分析,从吉林省松原市土样中分离到的昆虫病原线虫JLSY 003为Oscheius myriophila品系.本研究以大蜡螟末龄幼虫为寄主,测定该线虫的生物学特性.结果表明,JLSY 003浓度为80IJs/larva时具有较高的侵染力,致死中时间LT50为15.409 h,侵染24、48h...     

昆虫病原线虫共生细菌的研究概况

一、绪言Bovien(1937)首次报道了感染期的斯氏线虫Steinernema bibionis与细菌有共生的关系。以后,Weiser(1955)和Dutky(1959)分别发现昆虫病原线虫S.feltiae(=Neoaplectana carpocapsae)的捷克品系及DD—136品系与细菌亦有类似的关系。现已证明:至少有二个属的昆虫病原线虫可携带并将细菌释放到活昆虫寄主的血淋巴中。这些线虫为斯氏线虫属steinernema和异小杆线虫属Heterorhabditis。     

有效防治蛴螬的昆虫病原线虫鉴定及其生物学特性

为筛选出对华北地区蛴螬具有较强致病力的昆虫病原线虫,从河北省采集的30份土样中分离线虫,通过形态学和分子生物学方法进行鉴定,分析其生物学特性,并测定线虫对该地区3种蛴螬的致病力。结果表明,经鉴定所分离的昆虫病原线虫为樱桃异小杆线虫Heterorhabditis beicherriana的1个品系,将其命名为LF品系;该线虫具有较强的耐高温能力,38℃水浴12 h后存活率达28.4%;具有较好的耐干燥能力,相对湿度50.5%处理9 h后存活率可达80.0%,在此条件下仍然具有较强的侵染能力,可使大蜡螟Galleria mellonella在72 h内全部死亡;具有较强的水平运动能力,30℃处理24 h后有42.2%的个体迁移到3.6 cm外培养皿圆孔处。该线虫对蛴螬具有较强的致病力,室内试验中,在200 IJs/头剂量下对华北大黑鳃金龟Holotrichia oblita、暗黑鳃金龟Holotrichia parallela和铜绿丽金龟Anomala corpulenta幼虫处理7 d后,3种幼虫1龄末期幼虫死亡率均可达70.0%以上;室外盆栽试验中,5 000 IJs/盆剂量下处理7 d后,3种幼虫2龄中期幼虫死亡率均达到了80.0%以上。表明樱桃异小杆线虫LF品系对华北地区蛴螬类地下害虫生防潜能巨大。     

一种对桃小食心虫高毒力的斯氏线虫Steinernema sp.(CB-2Y)

本研究在室内用“沙埋法”比较了两种斯氏属昆虫病原线虫Steinernema sp.(CB-2Y)和S.feltiae Agriotos对桃小食心虫的侵染力,结果表明CB-2Y线虫对桃小食心虫幼虫和冬茧的侵染力都高于Agriotos线虫。接线虫笫7天桃小食心虫LD50,CB-2Y组为49条线虫,而Agriotos组为158条;冬茧的LD50分别为1330条和24046条。在桃小冬茧开始活动期(6月15日)分别施用两种线虫,一个月后检查桃小食心虫成虫羽化率,CB-2Y线虫的控制效果明显优于Agriotos,在1024条线虫/桃小食心虫冬茧时(75条/cm~2),越冬代桃小食心虫的羽化率分别为8.2％和29.2％。     

海南槟榔园昆虫病原线虫对红脉穗螟的致病力

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。     

Comparative efficacy of indigenous heterorhabditid nematodes from north western Himalaya and Heterorhabditis indica (Poinar,Karunakar & David) against the larvae of Helicoverpa armigera (Hubner)

The efficacy of three Heterorhabditis spp of entomopathogenic nematodes (EPNs) from north western Himalaya, India was studied against the larvae of pod borer, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), under the laboratory conditions. The larvae were exposed to 10, 20, 30 and 40 infective juveniles (IJs) of each nematode species for different time periods and they were found to be susceptible to all the EPNs tested. However, the susceptibility of larvae to nematode infection varied according to the concentrations of IJs and their exposure periods. The efficacy of these indigenous entomopathogenic nematodes was also compared against commercially available entomopathogenic nematode, H. indica. Appreciably good performance was achieved by H. bacteriophora (HRJ), which showed 73.3% mortality of insect larvae in 96 h exposure time against third instar larvae, while H. indica produced 80.0% mortality. However it was noticed that with the advancement of larval stage its mortality rate reduced and vice versa with the exposure period. All tested EPNs were also found to reproduce within the host and maximum production of IJs was recorded in H. bacteriophora (26.0 ± 3.76 × 10³ IJs/larva) at the concentration of 40 IJs/larva.     

Biological control potential of Turkish entomopathogenic nematodes against the Mediterranean fruit fly <Emphasis Type="Italic">Ceratitis capitata</Emphasis>

The entomopathogenic nematodes Steinernema weiseri, S. feltiae, S. carpocapsae and two strains of Heterorhabditis bacteriophora, isolated from Turkish soils, were evaluated against larvae of the Mediterranean fruit fly (medfly) Ceratitis capitata in plastic cups under laboratory conditions with sandy loam soil and 10% moisture level. At a rate of 100 infective juveniles (IJs)/cm², the last instar larvae of C. capitata were susceptible to the entomopathogenic nematodes: the S. feltiae 09-31 strain recovered from Aydin provided 78% mortality, whereas S. weiseri and S. carpocapsae killed 50% and 56% of the larvae, respectively. Both strains of H. bacteriophora species caused less than 50% mortality. Except for S. feltiae, the majority of infected medflies died as prepupae or pupae within the puparia. More than 90% larval mortality was recorded at 200 and 400 IJs/cm² for S. feltiae. None of the nematode isolates infected the medfly pupae within the puparia. In pot experiments containing soil, S. feltiae caused 96% and 97% mortality at 100 and 200 IJs/cm², respectively. In pot experiments with grass present, more than 94% mortality was obtained in the presence of grass roots.     

Susceptibility of the taro beetle,Papuana uninodis,to entomopathogenic nematodes

Six strains of entomopathogenic nematodes, Steinernema glaseri (Steiner) (Biosys #326, nc 34, gb), S. feltiae = bibionis (Filipjev) (Biosys #349), S. carpocapsae Weiser (Biosys #25) and Heterorhabditis zealandica Poinar, were evaluated in laboratory tests against taro beetles, Papuana uninodis Prell. Larvae of this species and adult Papuana Arrow spp. were found to be susceptible to entomopathogenic nematodes. The best results were obtained with S. glaseri #326 in larval and adult P. uninodis . The dose causing 50% mortality (LD ) for third instar P. uninodis larvae in Petri dish assays ranged from almost 7000 nematodes/larva for 1 days exposure to less than 250 nematodes/larva for 6 days; in pot assays the concentration causing 50% mortality (LC ) in 2 weeks was 1.4 106 nematodes/m2. For 50 adults in Petri dishes with soil, the LD was ca 20 000 nematodes/ 50 adult for 1 weeks exposure and ca 6000 nematodes/adult for 3 weeks. In pot assays the LC was 2.5 106 nematodes/m2 in 3 weeks. 50 Preliminary tests showed that P. huebneri (Fairmaire) and P. woodlarkiana laevipennis Arrow adults were also most susceptible to S. glaseri #326. A field test on adults Papuana uninodis did not result in damage reduction but served to illustrate the practical difficulties of applying nematodes in remote areas. 50     

利用昆虫病原线虫防治草菇双额岩小粪蝇

草菇双额岩小粪蝇Bifronsina bifrons是当前草菇生产中的重要害虫。本文测定了5个线虫品系在（30±0.5）℃下对草菇双额岩小粪蝇的致死率和LT50。结果表明,各线虫品系在浓度4000 IJs mL 1下的LT50范围为2.13～4.71 d,其中夜蛾斯氏线虫Steinernema feltiae SN品系对双额岩小粪蝇的毒力最大,LT50为2.13 d,侵染5 d后的致死率达86.67%。菇房施用4×106IJs.m 2S.feltiae SN品系和嗜菌异小杆线虫Heterorhabditisbacteriophora H06品系悬浮液于培养基表面6 d后,对双额岩小粪蝇的防治效果分别达到70.37%和45.68%,SN线虫对双额岩小粪蝇的防效与阿维菌素相当。     

不同品系昆虫病原线虫抗逆性分析

昆虫病原线虫作为一种高效的生物防治因子,具有广泛的应用前景.但昆虫病原线虫的生物活性受自然环境影响较大,筛选抗逆优良品系对于更好地推广和应用昆虫病原线虫具有十分重要的意义.为了评价昆虫病原线虫的抗逆性差异及生防潜力,在室内条件下测试了17个采自不同地区的昆虫病原线虫品系对高温、低温及干燥环境的抗性.结果显示:Stein...     

4种杀虫剂对甘草胭珠蚧的防治效果

甘草胭珠蚧Porphyrophora sophorae(Arch.)是人工栽培甘草的主要害虫。采用灌根、土壤处理法研究了35%吡虫啉悬浮剂、70%噻虫嗪水分散粒剂、48%毒死蜱乳油和5%毒死蜱颗粒剂4种杀虫剂对甘草胭珠蚧的防治效果。结果表明,8月中旬施药各药剂的防治效果均低于50%,但可有效降低翌年春季田间的虫口密度;6月中旬采用35%吡虫啉悬浮剂和70%噻虫嗪水分散粒剂灌根的防效可达80%以上。建议生产中可在6月中旬或之前采用灌溉后进行35%吡虫啉悬浮剂1 500倍或70%噻虫嗪水分散粒剂7 500倍液300mL/株灌根的措施防治甘草胭珠蚧。     

嗜菌异小杆线虫的分离鉴定及生物学特性分析

为了发掘具有耐高温特性的昆虫病原线虫,本实验室对在山东地区采集的122份土样进行了线虫分离,得到异小杆线虫JNR,扩增其ITS基因和D2-D3基因,并构建系统进化树,分析可得:线虫JNR与嗜菌异小杆线虫Heterorhabditis bacteriophora在同一分支,同源性达到98%以上,为嗜菌异小杆线虫品系。为进一步了解该线虫品系的生物学特性,本试验研究了其侵染力、高温耐受力及水平运动能力。结果表明,线虫JNR有较好的耐热性,38℃条件下处理16 h,存活率最高54%,24 h时为32%;40℃水浴处理2 h,低浓度500 IJs/mL下存活率28%,3 h后全部死亡。对大蜡螟和小菜蛾的生测结果显示,在10、15、20、25、30、35、40、60、120、240 IJs/头剂量下处理24 h,蔬菜害虫小菜蛾先出现死亡,大蜡螟则在48 h后出现死亡;大于20 IJs/头剂量下,处理48 h后线虫对大蜡螟的校正死亡率达到59.5%,高于对小菜蛾的侵染效果。在剂量120 IJs/头以上,72 h后寄主的校正死亡率均能达到100%。异小杆线虫JNR在30℃条件下水平运动能力比在18、25℃时强,48 h时有31%的个体运动到3.6 cm处。以上研究表明,该线虫有较强的侵染力,特别是在温度相对较高时具有较好的耐热力和水平运动能力,对防治蔬菜田小菜蛾具有应用开发潜力。