安徽虫瘟霉菌株的强毒杀蚜应与侵染速率

报道安徽虫瘟霉（Ｚｏｏｐｈｔｈｏｒａ ａｎｈｕｉｅｎｓｉｓ）菌株Ｆ９７０２８对桃蚜（Ｍｙｚｕｓ ｐｅｒｓｉｃａｅ）的强毒杀蚜活性。以７个孢子剂量（０．４￣１０．４个孢子／ｍｍ＾２）接种２￣３龄若蚜（５２￣８６头／剂量）,连续观察７ｄ,所获数据经时间－剂量－死亡率模型模拟分析,接种后第３￣７ｄ的ＬＤ５０分别为３４．８、８７、１．５、０．７和０．４个孢子／ｍｍ＾２;在所有剂量范围内ＬＴ５０为２．９￣６     

不同温湿度组合对安微虫瘟霉诱发桃蚜病害的影响

用孢子浴方法,对４２批次桃蚜Ｍｙｚｕｓ ｐｅｒｓｉｃａｅ（３０－６０头／批）接种大剂量（孢子７９－９０个／ｍｍ＾２）安徽虫瘟霉Ｚｏｏｐｈｔｈｏｒａ ａｍｈｕｉｅｎｓｉｓ的分生孢子,在２０℃下保湿２４ｈ后转入不同温度（１０℃、１５℃、２０℃、２５℃、３０℃及自然变温下１．５－１６．６℃和８．５－２０．２℃）和温度（５０％、６５％、８０％、９０％９５％及１００％ＲＨ）的组合条件下观察桃蚜的反应。结果表     

安徽虫瘟霉对桃蚜的生物测定与时间一剂量效应分析*

用“孢子浴”法将人工培养的安徽虫瘟霉(Zoophthora anhuiensis)对桃蚜(Myzuspersicae)接种而进行定量生物测定(18℃,光周期为L：D 12：12),包括10个剂量(1．5～197．7个分生孢子／mm²),每剂量处理蚜虫64～120头,逐日观察记载死亡数至第7d。接种后第3d在高剂量处理中始见少量死蚜,第4～6d为死蚜盛期。所获数据很好地拟合时间一剂量一死亡率模型,由模型参数估计出该菌作用于桃蚜的时间效应随剂量增大而减小,在37.1～197.7个分生孢子／mm² 的剂量范围内LT₅₀值为4.5～6.7d．剂量效应在接种后随时间递减,第5～7d的LD₅₀分别为86.8、43.7和34.1个分生孢子／mm²。结果表明,安徽虫瘟霉是一种较为理想的杀蚜微生物,在寄主体内的潜伏期为4～5d。     

侵染双翅目昆虫的新种,新记录,新组合及新修订

记录了最近在中国记载的侵染双翅目昆虫的虫霉目两个新种,毛蚊虫疠霉（Ｐａｎｄｏｒａｂｉｂｉｏｎｉｓ）发现于浙江元的毛蚊（Ｂｉｂｉｏｓｐ．）其初生分生孢子拟卵形,多对称１４．４～２０．５×７．２～１１．５μｍ（平均１６．５～１７．４×８．４～１０．４μｍ）Ｌ／Ｄ１．４～２．３（平均１．７～２．０）;假根２倍粗于分生包子梗,末端膨大为吸盘状固着器,休眠孢子外壁刺毛状。１９．１～２１．４μｍ,食蚜蝇干尸霉     

飞虱虫疠霉对褐飞虱的毒力(英文)

飞虱虫疠霉（Ｐａｎｄｏｒａ ｄｅｌｐｈａｃｉｓ（Ｈｏｒｉ） Ｈｕｍｂｅｒ）是我国稻区常见引发稻飞虱流行病的重要病原真菌。本研究用从稻飞虱虫尸上分离获得的两个飞虱虫疠霉菌株Ｆ９５１２７和Ｆ９５１２９分别对褐飞虱（Ｎｉｌｏｐａｒｖａｔａｌｕｇｅｎｓ Ｓｔａｌ）进行了毒力测定。将 ４－５龄若虫曝露在液体培养所获的产孢菌丝平板下进行“孢子浴”接种,通过控制孢子浴时间获得系列接种剂量。各剂量处理的若虫分别饲养于生长培养箱中,温度２５℃,光照１２Ｌ∶１２Ｄ,相对湿度接近饱和,逐日检查死亡数。所得数据很好地拟合时间－剂量－死亡率模型,由此获得用于估计毒力指标的时间和剂量效应参数。接种后 ６－８ ｄ, Ｆ９５１２９和 Ｆ９５１２７的 ＬＤ_（５０）分别为 ３２７、 １２２、４６孢子／ｍｍ~２和４０９、 １３３、 ７４孢子／ｍｍ~２, Ｆ９５１２７在９５孢子／ｍｍ~２剂量下的 ＬＴ_（５０）为７．６ｄ,而Ｆ９５１２９的ＬＴ_（５０）则从１７２孢子／ｍｍ~２时的 ６． ６ｄ下降到 ５２５孢子／ｍｍ~２时的５．６ｄ。根据所测毒力指标和剂量效应参数的分析比较,两个飞虱虫疠霉菌株对褐飞虱均具有中等毒力,且彼此间无显著差异。     

安徽虫瘟霉在侵染潜伏期内对桃蚜无翅成蚜生殖力的影响

在8个剂量（0．48－61．15个孢子.mm^-2)下测定安徽虫瘟霉F97029菌株对桃蚜（Myzus persicae (Sulzer))2-3龄若蚜（57－84头／剂量（的毒力,接种后第3－7d的半致死剂量LD50分别为3．09,.88,1.33,1.28,1.26个孢子／mm2,致死中时LT50为2－6d,随剂量增大而缩短,将该菌株按60个孢子.mm^-2的剂量接种桃蚜的无翅成蚜,在10,15,20,25℃下其侵染潜伏期分别为7．2,5．3,4．9,3．9d,温度与潜伏期呈显著负相关（r^2=0.94),在相同梯度温度下,接种成蚜在病害潜伏期内平均产若蚜7．97头,11．20头,11．86头和11．20头,与同期对照相比依次下降56．45％,41．58％,39．98％,49．02％,根据日观察数据建立接种后潜伏期内45．54％（15℃）,43．11％（20℃）,和50．84％（25℃）,内禀增长率（rm)比对照分别下降24．28％,16．98％,14．12％和20．13％,表明安徽虫瘟霉感染引发的真菌病害对桃蚜种群增长具有显著的抑制作用。     

安徽虫瘟霉菌株的强毒杀蚜效应与侵染速率*

报道安徽虫瘟霉（Zoophthoraanhuiensis）菌株F97028对挑蚜（Myzuspersicae）的强毒杀蚜活性。以7个孢子剂量（0．4～10．4个孢子／mm2）接种2～3龄若蚜（52～86头／剂量）,连续观察7d所获数据经时间－剂量－死亡率模型模拟分析,接种后第3～7d的LD50分别为34.8、8.7、1.5、0.7和0.4个孢子／mm2。在所用剂量范围内LT50为29～6.0d,随剂量增大而缩短。在接种后不同时段用0.1％百菌清水溶液处理被接种蚜体表面,结果显示,在15～20℃下,在0.7～1．8个孢子／mm2的剂量下接种后2h内的有效侵染率为42～58％,4h内为44％～74％,6h时达90％以上;在69～9．0个孢于／mm2的剂量下接种后1h,有效侵染率为57％～67％,2h内为77％～86％,4h内为78％～90％;高剂量（499～54．8个孢子／mm2）下接种后1h即达90％以上。与虫瘟霉属其它菌种或菌株对蚜虫的毒力比较,F97028菌株的毒力高28～117倍,为罕见的强毒杀蚜菌株。     

环境因素对安徽虫瘟霉生长发育的影响

安徽虫瘟霉是目前仅发现于我国的重要蚜虫病原真菌,对桃蚜具有明显的自然控制作用。本研究了温度和紫外光对安徽虫瘟等固体培养性状及不同温湿度组合对安徽虫瘟霉分生孢子萌发的影响。     

蜘蛛病原真菌一新种

虫壳属一新种大别山虫壳（Ｔｏｒｒｕｂｉｅｌａｄａｂｉｅｓｈａｎｅｎｓｉｓ）及其同时在蛛体上并存的无性型大别山球束梗孢（Ｇｉｂｅｌｕｌａｄａｂｉｅｓｈａｎｅｎｓｉｓ）。子囊壳表生至浅埋生,孔口黄色,子囊孢子弹射后呈波浪形弯曲。次生子囊孢子长柱形,９．４～１５．１×０．７～１．２μｍ。孢梗束单个或两个,白色,在其２／３处仍有分生孢子梗。分生孢子梗长２７～４４μｍ,光滑。分生孢子纺锤形,３．２～４．０×１．１～１．８μｍ。具糙梗孢式的共无性型方式,分生孢子线形,１１．０～２０．０×０．７～１．１μｍ。列出了该属已知种的检索表,并分别命以中名     

不同温湿度组合对安徽虫瘟霉 诱发桃蚜病害的影响

用孢子浴方法,对42批次桃蚜Myzus persicae（30～60头/批）接种大剂量（孢子79～90个/ mm²）安徽虫瘟霉Zoophthora anhuiensis的分生孢子,在20℃下保湿24 h后转入不同温度（10℃、15℃、20℃、25℃、30℃及自然变温1.5～16.6℃和8.5～20.2℃）和湿度(50%、65%、80%、90%、95%及100% RH)的组合条件下观察桃蚜的反应。结果表明,各组合条件下的桃蚜均能发病死亡,而且累计死亡率的显著差异存在于不同温度（F=7.46, P<0.01)和湿度间（F=12.54, P<0.01）。最适发病的温度为恒温20℃和变温8.5～20.2℃（日均温12.4℃）,死亡率随湿度升高而增大。在10～25℃和100% RH的组合中,温度的变化几乎不影响桃蚜的累计死亡率,但影响发病速率,在10℃、15℃、20℃和25℃下的致死时间LT₅₀值分别为8.4 天、7.1 天 、4.0 天和3.4 天。回归分析表明, 在100% RH下安徽虫瘟霉诱发桃蚜发病的起始温度为1.65℃。在10～15℃及自然变温下,病死蚜尸顺利产孢的湿度为80% RH;而在20～30℃下,蚜尸产孢的湿度为90% RH。在所有温湿组合的蚜尸中未见安徽虫瘟霉的休眠孢子发生。     

安徽虫瘟霉的黍米培养及其对桃蚜的侵染力

安徽虫瘟霉Zoophthora anhuiensis (Li) Humber是较难人工培养的蚜虫专化性病原真菌。将灭菌并适度熟化的黍米Panicum miliaceum L.作为固体基质与挑碎的安徽虫瘟霉平板菌落混合,在20℃和12L∶12D的温光条件下静止固体培养,获得了产孢潜能大、杀蚜活性强的米粒培养物。培养7天的黍米的产孢量达13.0×10⁴个孢子/粒,产孢持续时间长达6天。用此黍米培养物弹射的孢子对桃蚜Myzus persicae (Sulzer) 若蚜进行7.9～134.9个孢子/mm²共9个剂量的孢子浴接种,所获数据很好拟合时间 剂量 死亡率模型。接种后第5～7天各天的LC₅₀依次为59.8, 39.5和33.5个孢子/mm²,LC₉₀依次为354,234和198个孢子/mm²。在57.7～134.9个孢子/mm²的接种剂量范围内,致死中时LT₅₀从5.1天下降到4.3天。由此表明,安徽虫温霉的黍米培养不仅简单易行,而且菌种的产孢和侵染生物学特性在培养物中被充分体现,每颗米粒如同自然罹病而死的蚜尸,值得进一步研究开发和利用。     

Virulence, horizontal transmission, and sublethal reproductive effects of Metarhizium anisopliae (Anamorphic fungi) on the German cockroach (Blattodea: Blattellidae)

Virulence of Metarhizium anisopliae (Metschnikoff) Sorokin strain EAMa 01/121-Su against the German Cockroach, Blatella germanica (L.), was determined using four concentrations ranging from 4.2 x 10(6) to 4.2 x 10(9) spores per milliliter. The LD50 value was 1.4 x 10(7) spores per milliliter (56,000 spores per cockroach) and LT50 values were 14.8 days and 5.3 days for 4.2 x 10(8) and 4.2 x 10(9) spores per milliliter, respectively. An experiment was conducted to evaluate whether a fungal transmission could exist among infected and healthy cockroaches. Percentage mortality at a ratio of 1:10 of infected to unexposed cockroaches was 87.5% and LT50 was 12.2 days, which indicated the potential of this strain to be horizontally transmitted and to rapidly spread the infection in the insect population. The effect of a sublethal dose (ca. LD60) of M. anisopliae EAMa 01/121-Su strain, applied topically on German cockroaches, was studied by reciprocal crossing. Othecal production, oothecal hatchability, and nymphal production declined upon exposure to M. anisopliae EAMa 01/121-Su strain. The mean number of oothecae laid by female was progressively and significantly reduced by fungal treatment from second oviposition period onwards. Oothecal hatch of fungally challenged females was reduced by 46-49%, oothecal viability by 48-85%, and nymphal production by 22-35%. Only treated females showed an effect on oothecal production, oothecal hatch, and nymphal production, although oothecal hatch was also governed by treated males at a higher significance level. Our results on virulence and horizontal transmission of fungal conidia of M. anisopliae EAMa 01/121-Su strain and its sublethal reproductive effects on German cockroach females are discussed in terms of its potential to decrease the pest status of B. germanica in the short and long terms.     

温度与光照对安徽虫瘟霉产孢格局的影响*

在不同温度（10～30℃）与光照（连续光照和连续黑暗）组合条件下进行了安徽虫瘟霉（zoophthoraanhuiensis）离体产孢格局的研究。结果表明,适于安徽虫瘟霉产孢的温度为10～20℃,但以15℃最适,不仅产孢快和产孢量大,而且不受光照的影响。在25℃下虽能产孢,但产孢量大幅减少,30℃下则不产孢,25℃可能是安徽虫瘟霉产孢的高温极限。全光照各温度处理的产孢量总是比全黑暗相应温度处理的产孢量高,说明光照对产孢具有刺激作用。在10℃和全光照的组合中,累计产孢量最高且持续产孢时间最长,而相同温度与全黑暗处理的产孢量却很低,显示光照在偏低温度下是影响安徽虫瘟霉产孢的关键因素。概而言之,光照主要影响安徽虫瘟霉的产孢量,而温度主要影响其产孢速率或进程。     

THE VIRULENCE OF THE ENTOMOPHTHORALEAN FUNGUS PANDORA DELPHACZS TO THE BROWN PLANTHOPPER NILAPARVATA LUGENS1)

Abstract The entomophthoralean fungus, Pandwa delphacis (Hori) Humber, is a pathogen frequently causing epizootics of the brown planthopper, Nilaparvata lugens Stal, in rice growing areas of China. Two isolates (F95127 and F95129) of the fungus obtained from mycosis-killed planthoppers collected in Zhejiang Province were bioassayed for their virulence to N. lugens. For inoculation, botches of 4– or 5-in-star-old nymphs from a laboratory population were exposed to time-varying spore shower from sporulating plates of fungal mass produced in Sabouraud liquid medium, resulting in 8 and 6 dosages for F95129 and F95127, respectively. The nymphs treated at each dosage were maintained on rice plants at 25°C and a photophase of 12L: 12D in growth chamber (nearly 100% RH) and were examined daily for mortality. The resulting data were well fitted to time-dose-mortality model, generating parameters of time and dose effects for estimation of virulence indices. The LD₅₀ values 6–8 d after exposure were 327, 122 and 46 conidia/mm² for F95129 and 409, 133 and 74 conidia/mm² for F95127, respectively. The LT₅₀ estimated for F95127 was 7. 6 d at 95 conidia/mm² whereas that for F95129 decreased from 6. 6 d at 172 conidia/mm² to 5. 6 d at 525 conidia/mm². Based on these virulence indices and comparison of the slopes for dose effects from the model, the two isolates of P. delphacis had moderate virulence to N. lugens with insignificant difference to each other.     

Relative susceptibility of different stages of Rhodnius prolixus to the entomopathogenic hyphomycete Beauveria bassiana.

Laboratory bioassays were conducted to determine the relative susceptibility of eggs, 1st-, 3rd-, 5th-instar nymphs and adults of Rhodnius prolixus to one isolate of the entomopathogenic hyphomycete, Beauveria bassiana. Treatments consisted of directly spraying on insects of increasing doses of inoculum (3 x 10(2) to 3 x 10(5) conidia per cm2). Mortality due to all doses of conidia was very high in the five tested stages of the target insect. Experiments on eggs demonstrated that the fungal isolate was able to kill eggs before they hatched. Both time-mortality and dose-mortality responses showed that the susceptibility of R. prolixus varied according to its stage of development and increased with age. As a matter of fact, at the dose of 3 x 10(3) conidia per cm2, LD 50 varied between 11.2 days in 1st-instar nymphs and 6.4 days in both 5th-instar nymphs and adults. Comparison of LD50 permitted to estimate that 1st-instar nymphs were about 700-fold less susceptible than the two oldest stages.     

The relationship between conidial dose,moulting and insect developmental stage on the susceptibility of cotton aphid,Aphis gossypii,to conidia of Lecanicillium attenuatum,an entomopathogenic fungus

The cotton aphid is one of the most serious pests of greenhouse vegetable crops worldwide. It is difficult to control because field populations usually include simultaneously several insect developmental stages. The current research evaluated an isolate (CS625) of Lecanicillium attenuatum, a fungal pathogen of aphids, as to its virulence against different developmental stages of cotton aphid, Aphis gossypii. The influence on mortality of several other factors also was examined: (a) insect moulting, (b) the number of conidia attached to insect cuticles and (c) germination rates of conidia on cuticles of aphids at various developmental stages. Mortality of cotton aphids treated with L. attenuatum conidia varied according to the developmental stage of the host, i.e. the LT_50s with third-instar nymphs and adults was shorter than with first-instar nymphs. The number of spores attached to the surface of first-instar nymphs was approximately one-half of that on third-instar nymphs and adults. Also, the level of spore germination on the surface of first-instar nymphs was lower than on the surface of other stages of the aphid. After moulting, the numbers of conidia attached to new insect cuticles were less than on exuviae. These results suggest that early nymphal stages of cotton aphids may escape fungal disease due, at least in part, to a combination of three factors: low numbers of conidia attached to their cuticles; low levels of conidial germination and rapid ecdyses, which removed conidia before their germ tubes penetrated the host hemolymph.     

新型球孢白僵菌孢子悬乳剂的高效杀蚜活性及其评价方法

用球孢白僵菌（Beauveria bassiana）SG8702的孢子悬乳剂与未剂型化孢子粉对桃蚜进行了杀蚜活性对比测定。孢子悬乳剂与孢子粉分别用水稀释成5个序列浓度,对甘蓝叶片上蚜虫进行相同时间的弥雾接种,前者孢子附着量分别为1.5～701.1个孢子/mm2 ,后者附着量分别为2.8～1005.9个孢子/mm2。蚜虫接种后置于23℃和12L：12D条件下饲养,定时观察8d。经时间—剂量—死亡率模拟分析,悬乳剂的剂量效应参数明显高于孢子粉,且杀蚜时间效应提前。用模型参数估计悬乳剂和孢子粉的LC50,接种后第4天分别为9.0和634个孢子/mm2,第7天为3.3和5.3个孢子/mm2。悬乳剂和孢子粉的LT50随叶面孢子附着量增大而下降,在100个孢子/mm2下为3.2d和4.5d。这表明孢子悬乳剂的杀蚜活性比未剂型化的孢子粉显著增强。作者讨论了杀虫微生物制剂评价的技术规范问题。     

Development of a novel bioassay for estimation of median lethal concentrations (LC50) and doses (LD50) of the entomopathogenic fungus Beauveria bassiana, against western flower thrips, Frankliniella occidentalis

To conduct laboratory experiments aimed at quantifying secondary acquisition of fungal conidia by western flower thrips (Frankliniella occidentalis), an efficient assay technique using Beauveria bassiana as the model fungus was developed. Various application protocols were tested and it was determined that the percent mortality did not vary among protocols. Peak mortality of second-instar nymphs, under constant exposure to conidia, occurred 5 days post-inoculation. Second-instar thrips that were exposed to conidia within 24 h of the molt to second instar were more susceptible to Beauveria bassiana than thrips exposed after times greater than 24 h post-molt. Conidia efficacy, which was monitored at 24 h intervals, did not differ significantly within 72 h. A test of the final bioassay system was conducted in a series of assays aimed at determining the LD50 of B. bassiana technical powder against second-instar western flower thrips. It was determined that B. bassiana (strain GHA) is highly effective at very low doses (LD50 of 33-66 conidia/insect).