从青杨天牛分离的几种致病翼菌

从青杨天牛虫尸上分离出枝顶孢霉、球孢白僵菌、金龟子绿僵菌、轮状镰刀菌和尖孢镰刀菌5种病原真菌,其中枝顶孢霉为国内新记录。利用青杨天牛蛹对五种致病真菌进行了生物测定,5种病原菌的致病力顺序为：金龟子绿僵菌>球孢白僵菌>枝顶孢霉>尖孢镰刀菌>轮状镰刀菌。青杨天牛不同虫期对金龟子绿僵菌的易感性顺序为：l龄幼虫>蛹>老熟幼虫。利用金龟子绿僵菌和枝顶孢霉菌液田间防治青杨天牛幼虫,死亡率分别为95．56％及48．72％o     

感染松墨天牛的金龟子绿僵菌菌株的初步筛选

松墨天牛是松材线虫病的主要媒介昆虫,本文对分离自松墨天牛的6株金龟子绿僵菌,以及从光肩星天牛、大蜡螟、伊藤厚丝角叶蜂和土蝽上分离的各1个菌株,共10个菌株的产孢情况、孢子萌发率进行研究;在此基础上选出金龟子绿僵菌1291、1349和2049三个菌株及球孢白僵菌F-263菌株,采用成虫跗节接种法和幼虫浸渍法进行室内松墨天牛及大蜡螟的毒力测定比较。结果表明,供试绿僵菌菌株对松墨天牛幼虫在接种15天后的感染僵虫率为76.9％～93.1％(1×10⁷孢子/mL);成虫在接种20天后的僵虫率亦达57.9％～75.0％(6.5×10⁵～3.4×10⁶孢子/成虫);2049菌株表现尤其突出;对应的球孢白僵菌F-263对幼虫和成虫的僵虫率分别是96.3％(1×10⁷孢子/mL)和55％(9.7×10⁵孢子/成虫)。但这3个金龟子绿僵菌菌株对大蜡螟的毒力较低,存在较明显的寄主专化性。这3个菌株今后在防治松墨天牛方面具有较大开发应用价值。     

西花蓟马高毒力虫生真菌筛选及其生防应用潜力的研究进展

西花蓟马是一种外来入侵的世界性害虫,对农林业危害巨大。查阅国内外相关文献,综述了当前防治西花蓟马的虫生真菌的种类、高毒力菌株的筛选及防治现状。现已知西花蓟马的寄生病原真菌有5种,包括蜡蚧轮枝菌(半知菌:丝孢目)、球孢白僵菌(半知菌:丝孢目)、金龟子绿僵菌(半知菌:丝孢目)、玫烟色棒束孢(半知菌:束梗孢目)和小孢新接霉。其中,球孢白僵菌、金龟子绿僵菌在西花蓟马的生物防治中应用最广,具有良好的开发应用潜力,部分防效好的虫生真菌已申请专利及实现工厂化生产。     

白僵菌生物防治林中虫生真菌群落结构分析

对白僵菌生物防治林中虫生真菌群落的结构研究表明,长期接种式释放白僵菌的马尾松林中虫生真菌共有属7种.球孢白僵菌的数量占绝对优势,为总数的63.22%;拟青霉次之,占25.86%;绿僵菌占9.20%;轮枝孢仅占1.72%.从寄主昆虫的多样性来看,球孢白僵菌和环链拟青霉的Brillouin多样性指数分别为3.56和2.315,均匀度分别为0.81和0.865;粉拟青霉和蜡蚧轮枝孢的多样性指数分别为1.71和0.862,均匀度为0.963和1.000而黄绿绿僵菌、金龟子绿僵菌和玫烟色拟青霉多样性和均匀度指标均较低.不同季节中被白僵菌侵染的寄主昆虫多样性指数呈现出春秋高、夏季低的趋势,反映了白僵菌种群的季节性变化.     

人工栽培蛹虫草的病原真菌

蛹虫草规模化栽培过程中,真菌病害普遍发生且危害严重。本研究对人工栽培蛹虫草中真菌病害进行调研,对病原真菌进行分离、纯化、鉴定及致病性检验,并分析病害发生的特点。结果发现引起蛹虫草病害的病原真菌主要有虫草生齿梗孢、产扁虫菌素单端孢、镰刀菌、裂褶菌、哈茨木霉、淡紫拟青霉、稻绿核菌、粉红枝穗霉、卵孢单端孢、扩展青霉、黄曲霉和黑曲霉。其中虫草生齿梗孢为引起蛹虫草侵染性病害的主要病原真菌。虫草生齿梗孢、产扁虫菌素单端孢、镰刀菌、裂褶菌和哈茨木霉主要为害蛹虫草子实体;淡紫拟青霉、稻绿核菌、粉红枝穗霉、卵孢单端孢、扩展青霉、黄曲霉和黑曲霉主要为害栽培料与蛹虫草菌丝体。镰刀菌、裂褶菌、哈茨木霉、淡紫拟青霉、稻绿核菌和粉红枝穗霉为引起蛹虫草病害的首次报道。本研究为蛹虫草病害防控奠定基础,以促进产业健康发展。     

虫草及其无性型中的抗肿瘤细胞活性成分

较系统地总结了目前在虫草及其无性型中发现的抗肿瘤细胞活性成分.其中冬虫夏草、蛹虫草、大团囊虫草、单侧虫草、戴氏虫草和拟蛹虫草等虫草以及它们的无性型蛹拟青霉、细脚拟青霉、金龟子绿僵菌和球孢白僵菌等虫生真菌代谢物中抗肿瘤细胞活性成分,其结构包括多糖类、甾醇类、含氮化合物和杂环化合物等多个类型.     

黄氏枝膜叶蜂生物学特性及金龟子绿僵菌对其幼虫的致病力

【目的】黄氏枝膜叶蜂Cladiucha huangbki是新发现的叶蜂科(Tenthredinidae)枝膜叶蜂属Cladiucha种类,以幼虫取食危害乳源木莲Manglietia yuyuanensis叶片,虫口密度大, 严重影响乳源木莲的生长。本研究旨在明确该虫的生物学特性,并筛选出对该虫具有高致病力的金龟子绿僵菌Metarhizium anisopliae菌株,为高效治理该虫提供理论基础和生物防治资源。【方法】以林间调查和室内饲养观察相结合的方式,观察黄氏枝膜叶蜂的各发育阶段形态特征和生物学特性(寄主植物、分布和生活史);采用孢子悬浮液喷雾法筛选高致病力金龟子绿僵菌菌株。【结果】林间和室内观察结果表明,黄氏枝膜叶蜂幼虫取食木兰科木莲属植物,在福建永安市一年发生1代,以老熟幼虫(预蛹)在土室中越夏、越冬;翌年3月上旬化蛹,3月下旬成虫羽化,4月上旬为雌虫产卵高峰期,4月中旬幼虫出现,4月下旬至5月上旬为幼虫危害高峰期,5月中旬老熟幼虫开始入土做土室,入土深度30~150 mm。室内金龟子绿僵菌不同菌株对黄氏枝膜叶蜂幼虫致病力测定结果表明,以1×10⁷孢子/mL悬浮液喷雾11 d后,不同菌株对其幼虫的校正死亡率均超过85%,其中MaQZ-01, MaYTTR-04-05, Ma3和MaFZ-13 4个菌株感染的叶蜂幼虫校正死亡率为100%。菌株MaFZ-08感染引起的黄氏枝膜叶蜂僵虫率最高,为60%;其次是MaYTTR-04-05,引起的僵虫率为50%。金龟子绿僵菌各菌株对黄氏枝膜叶蜂幼虫的致死中时间(LT₅₀)相差不大,在6 d左右,其中MaYTTR-04-05菌株的LT₅₀最短,为5.090 d。【结论】黄氏枝膜叶蜂在福建永安一年发生1代,5月中、下旬老熟幼虫入土做土室化为预蛹越夏越冬。本研究筛选出对黄氏枝膜叶蜂幼虫致病力强的金龟子绿僵菌MaYTTR-04-05菌株,在其防治上有良好的应用前景。     

陕西红脂大小蠹天敌种类调查

对陕西红脂大小蠹Dendroctonus valens LeConte危害区的天敌种类调查表明,寄生于红脂大小蠹的病原真菌共有5种,其中幼虫期有头孢霉Cephalosporium sp.、球孢白僵菌Beauveria bassiana和拟卵孢霉Ovulariopsis sp.,成虫期有球孢白僵菌Beauveria bassiana、枝顶孢霉Acremonium sp.、头孢霉Cephalosporium sp.、木霉Trichoderma sp.4种,其中以球孢白僵菌和枝顶孢霉Acremonium sp.的致病能力最为显著。捕食性天敌昆虫主要有西岳蛇蛉Agulla xiyue Yang et Chou、日本弓背蚁Camponotus japionicus Mayr、中华红林蚁Formica sinensis Wheeler、蚁形郭公甲Thanasimus formicarius(L.)及纤细阎甲Platysoma attenuata(LeConte),它们对红脂大小蠹均有较明显的控制作用。寄生性天敌主要有1种寄生蝇和1种茧蜂。     

绿僵菌与3种杀虫剂混配对樟巢螟的协同作用

采用定量喷雾法测定了绿僵菌、白僵菌以及3种杀虫剂对樟巢螟Orthaga achatina低龄幼虫的室内毒力,并测定了金龟子绿僵菌Ma09与3种杀虫剂混配后的协同作用。结果显示：4种昆虫病原菌菌株均对樟巢螟2~3龄幼虫具有较好的致死效果,用绿僵菌和白僵菌孢悬液处理后,死亡高峰期在3~4 d;白僵菌GDLY9的防治效果最好,处理浓度为1×109孢子/mL下LT50和LT90分别为3.01、3.95 d,金龟子绿僵菌Ma09、3297效果相当,黄绿绿僵菌Mf985的LT50相对低一些,但是LT90优于金龟子绿僵菌Ma09和3297。金龟子绿僵菌Ma09与苯氧威、除虫脲和短稳杆菌混配后均表现出增效作用,协同指数分别为20.43、27.53和33.13。     

几种虫生真菌对斜纹夜蛾的致病性

用布氏白僵菌、球孢白僵菌、玫烟色拟青霉、绿僵菌和莱氏野村菌5种真菌的固体培养物,对斜纹夜蛾2、3龄幼虫进行了毒力测定.结果表明：布氏白僵菌和莱氏野村菌两种菌株对斜纹夜蛾幼虫有明显的致病效果,对2龄幼虫的致死中时(LT₅₀)分别为2.95 d和4.10 d,累计校正死亡率分别为100%和95.2%;对3龄幼虫的致病力低于2龄,致死中时(LT₅₀)分别为19.67 d和19.63 d,累计校正死亡率分别为56.6%和52.2%.玫烟色拟青霉、球孢白僵菌两菌株也有一定的致病力,对2龄幼虫的致死中时(LT₅₀)分别为4.89 d 和6.34 d,累计校正死亡率分别为85.7%和71.4%.     

Food consumption by Chilo partellus (Lepidoptera: Pyralidae) larvae infected with Beauveria bassiana and Metarhizium anisopliae and effects of feeding natural versus artificial diets on mortality and mycosis

Second and third instar Chilo partellus larvae were infected with Beauveria bassiana and Metarhizium anisopliae (both at 1x10(8)conidia/ml) and daily consumption of maize leaves was measured. Infection by the fungi was associated with reduced mean daily food consumption. Reduction in food consumption became evident 3-4 days after treatment with the fungi for second instar larvae and 4-5 days for third instar larvae. Four conidial concentrations, 1x10(5), 1x10(6), 1x10(7), and 1x10(8)conidia/ml, were tested against second instar larvae. Food consumption dropped by 70-85% when the second instar larvae were treated with the fungi at 1x10(8)conidia/ml. Reduction in food consumption by C. partellus larvae infected with B. bassiana and M. anisopliae may offset the slow speed of kill of the fungi. The effect of artificial versus natural diets on mortality and mycoses of second instar larvae treated with the fungi at 1x10(8)conidia/ml was determined. Larvae provided with artificial diet suffered little mortality and mycoses than larvae provided with maize leaves. The LT(50) was longer for larvae provided with artificial diet.     

Selection of a Highly Virulent Fungal Isolate,Metarhizium anisopliae Ma TB 101, for Control of Taro Beetle,Papuana uninodis (Coleoptera: Scarabaeidae)

Fungal isolates (31 Metarhizium anisopliae var. anisopliae , five M. anisopliae var majus , three Beauveria bassiana and four B. brongniartii ) originating from a wide range of geographical locations, insect species and soil types were tested against Papuana uninodis (Coleoptera: Scarabaeidae). In a first test series, spores were applied topically to third-instar larvae and adults. The most effective strain against P. uninodis larvae and adults was Ma TB 101, a M. anisopliae isolate from adult P. woodlarkiana . For adults, strain Ma FI 384, a M. anisopliae from Popillia japonica , was almost equally effective. The 11 most effective isolates (nine M. anisopliae var. anisopliae , one B. brongniartii and one B. bassiana ) with LT values of less than 6 weeks in 50 adults and/or less than 4 weeks in larvae were tested for their efficacy against adults and larvae of P. uninodis by application of spores to soil (107 spores/g). Ma TB 101 was significantly more effective against both adults and larvae (LT ca. 10 days) than all other isolates (LT > 50 50 3 weeks). Two other M. anisopliae strains, Ma F 248 from soil and Ma FI 384 from P.japonica , were more effective than most isolates in adults. The latter three M. anisopliae isolates were tested in a concentration series against third-instar larvae and adults. Mortality was concentration related. Isolates Ma F 248 and Ma FI 384 did not achieve 50% mortality within the test period at concentrations lower than 107 spores/g of soil or feed. For concentrations of Ma TB 101 from 1 107 to 2 105 spores/g the LT ranged from 13 to 30 days in adults and 12 to 24 50 days in third-instar larvae. Accordingly, concentrations causing 50% mortality (LC ) for Ma 50 TB 101 were significantly lower than for the two other M. anisopliae isolates tested.     

Effects of Metarhizium anisopliae (Metsch.) Sorok. and Beauveria bassiana (Bals.) Vuill. on the predatory stinkbug Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae)

Entomopathogenic fungi and the predatory stinkbug Podisus nigrispinus (Dallas) can target simultaneously the same or different pests in agroecosystems. Topical contact during fungal dispersion or spraying, walking on plant surfaces and ingestion of contaminated prey are some of possible ways of interactions between fungi and the predatory stinkbug. The impact of three isolates of Metarhizium anisopliae (Metsch.) Sorok. (866, 1022 and 1189) and Beauveria bassiana (Bals.) Vuill. (604, 634 and 561) against nymphs and adults of P. nigrispinus was investigated under laboratory conditions. M. anisopliae caused higher mortality compared to B. bassiana either by topical application or by dry residue on cotton leaves. Topic contact with both fungi caused higher mortality to the predator. No mortality confirmation was reported for the adults. Nymphs fed with cotton leafworm larvae Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) contaminated by the fungi had their reproduction affected, but this was not observed when adult predators fed on contaminated larvae. These findings suggest that isolates of M. anisopliae can cause mortality of P. nigrispinus nymphs by topical contact, while isolates of B. bassiana were less harmful by all ways of infection as compared to M. anisopliae.     

Laboratory bioassays of entomopathogenic fungi for control of Delia radicum (L.) larvae

Laboratory soil bioassays were performed at economic field rates for in-furrow (3.85 x 10(6)spores/g dry soil) and broadcast (3.85 x 10(5)spores/g dry soil) applications with three isolates of Metarhizium anisopliae (F52, ATCC62176, and ARSEF5520) and one isolate of Beauveria bassiana (GHA). All isolates tested were infective to second instar Delia radicum (L.). The conditionally registered M. anisopliae isolate (F52) performed best killing an average of 85 and 72% of D. radicum larvae at the high and low concentration, respectively. The mean LC50 and LC95 of F52 against second instar D. radicum was 2.7 x 10(6) and 1.8 x 10(8)spores/g dry soil, respectively. The use of F52 in an integrated management program is discussed.     

A new bioassay method reveals pathogenicity of Metarhizium anisopliae and Beauveria bassiana against early stages of Capnodis tenebrionis (Coleoptera; Buprestidae)

We used a newly developed bioassay method to demonstrate for the first time the potential of the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae to be used for the control of neonate larvae of Capnodis tenebrionis, a major threat to stone-fruit orchards in several countries. Four B. bassiana and four M. anisopliae isolates were all pathogenic for neonate larvae of C. tenebrionis; mortality rates 10 days after inoculation by dipping in a suspension with 10(8)conidia/ml varied from 23.5% to 100%. Three of the four M. anisopliae isolates caused 100% mortality. In most cases, postmortem hyphal growth and sporulation of M. anisopliae or B. bassiana was observed covering the larvae in their galleries. The eight isolates were also evaluated for pathogenicity to C. tenebrionis eggs at the same dosage. Only two B. bassiana isolates caused significant egg hatching reduction of 84.5% and 94.5%. Our results indicate that M. anisopliae and B. bassiana may be considered as promising for a new approach to prevent larval infestations by C. tenebrionis.     

Interaction of Metarhizium anisopliae (Metsch.) Sorok., Beauveria bassiana (Bals.) Vuill. and the parasitoid Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae) with larvae of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Chemical insecticides are broadly applied to control diamondback moth, Plutella xylostella (L.). Diamondback moth is a major pest of cruciferous worldwide, and resistance of this pest to insecticide has been often reported. Thus, this research investigated the interactions among the fungi Metarhizium anisopliae (Metsch.) Sorok., Beauveria bassiana (Bals.) Vuill., and the larval-pupal parasitoid Oomyzus sokolowskii (Kurdjumov) before and after application of the fungi on DBM larvae offered to the parasitoid. The experiment was carried out at 26+/-l degreeC, 75+/- 5% RH and 12h photophase using a completely randomized design, with eight treatments with six replications each. The isolates E9 of M. anisopliae and ESALQ 447 of B. bassiana, were used at the concentration of 10(7) conidia ml(-1). The results showed that M. anisopliae and B. bassiana reduced the parasitism of P. xylostella by O. sokolowskii. Additive effects were found on the mortality of P. xylostella with the different combinations among the fungi and parasitoid, except for the treatment B. bassiana inoculated 24h before exposition of the larvae to O. sokolowskii. The isolates were more efficacious when applied after exposition of the larvae to the parasitoid. The efficiency of O. sokolowskii was negatively influenced by the presence of the fungi, mainly when the fungi were applied 24h before diamondback's larvae were exposed to the parasitoid. The association of the fungi with the parasitoid presents potential to be tested in field. The use of these natural enemies in the integrated management of P. xylostella may economically improve the cabbage productive system, especially for organic farming.     

The Susceptibility of Boophilus annulatus (Ixodidae) Ticks to Entomopathogenic Fungi

The pathogenicity of five species of entomopathogenic fungi (Deuteromycetes, species: Beauveria bassiana, Metarhizium anisopliae, Metarhizium flavoviride, Paecilomyces fumosoroseus and Verticillium lecanii ) to the various developmental stages of Boophilus annulatus ticks was compared under laboratory conditions. M. anisopliae and B. bassiana strains were most virulent to engorged females and caused 85-100% mortality within 7-10 days post-inoculation (PI). The highest mortality of engorged females caused by other fungi reached only 25-60%. All tested fungi prevented or reduced the egg laying capability of the ticks several days before their death. Females surviving after treatment with the most virulent M. anisopliae strain (Ma-7) reached only 7-8% of their egg laying capacity as compared with the control. Other fungi caused a reduction of the weight of laid eggs by 35.4-80.8% as compared with untreated females. Only M. anisopliae and B. bassiana strains caused 70-98% mortality of the treated eggs. Unfed larvae of Boophilus annulatus were sensitive to M. anisopliae and M. flavoviride strains. The Ma-7 strain was most virulent to unfed larvae, with a mortality rate of 80.4% at a concentration of 1 ×107 spores ml -1 and 100% mortality at a concentration of 1 ×108 spores ml -1 .     

Evaluation of Metarhizium anisopliae (Metsch) Sorok. to target larvae and adults of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae) in soil and fiber band applications

The aim of this work has been to evaluate in the laboratory the potential of entomopathogenic fungi against adults and larvae of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae) through fiber band application and a potted plant bioassay with soil application, respectively. Our previous findings revealed that Metarhizium anisopliae EAMa 01/58-Su isolate was the most virulent against neonate larvae of the buprestid. In the present work, M. anisopliae EAMa 01/58-Su isolate has been also shown to be highly virulent against adult beetles by immersion in a conidial suspension; thus it was selected to accomplish our objectives. When adult beetles were stimulated to climb 100 x 200 mm non-woven commercial fiber bands impregnated with conidia of M. anisopliae EAMa 01/58-Su isolate, total mortality rates varied from 85.7% to 100.0%; whereas no significant correlation was detected between the time needed to cross the band (mean value 648.7+/-22.4s) and the time of death, with mean average survival time ranging between 10.3 and 16.0 days, compared to 28 days of the controls. Potted seedlings (5-6 months old) of cherry plum (Prunus myrobalana Lois.), a commonly used apricot rootstock, were used to study the efficacy of soil treatment with M. anisopliae EAMa 01/58-Su isolate against neonate C. tenebrionis larvae. The soil inoculation with M. anisopliae EAMa 01/58-Su isolate had a significant effect on the mean number of dead larvae recovered from the roots, with mean mortality ranging from 83.3% to 91.6%; whereas no significant differences were detected between the three fungal doses. In all cases, dead larvae found within roots exhibited external signs of fungal growth. Hence, it may be possible to use M. anisopliae EAMa 01/58-Su isolate in a biocontrol strategy targeting both adults and larvae of C. tenebrionis.