Specificity of natural resistance to trematode infections in Biomphalaria glabrata

The 10-R2 strain of Biomphalaria glabrata was strongly resistant to various strains of Schistosoma mansoni in its laboratory of origin (NIH) and to three strains of S. mansoni we tested against it. However, subsequent development of three inbred lines of B. glabrata 10-R2 snails, separately maintained in our San Francisco laboratory, showed slight loss of resistance in one colony, very much less resistance (or partial susceptibility) in another, and retention of the original resistance in a third to the Puerto Rico (PR-1) strain of S. mansoni. No selection for resistance to infection was involved in the breeding protocol for these 10-R2 lines, so the changes were apparently random ones that became established in the separate inbred substrains. In spite of their changed response to the PR-1 strain of S. mansoni, all three 10-R2 substrains retained only slightly diminished resistance to S. mansoni Lc-1 strain and an essentially undiminished resistance to irradiated Echinostoma lindoense, E. paraensei and E. liei sporocysts. This suggests that natural resistance to S. mansoni PR-1 in B. glabrata is specific, a response that differs from the host response to either S. mansoni Lc-1 or to the echinostomes.     

Virulence of entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) against Tipula paludosa (Diptera: Tipulidae), a turfgrass pest on golf courses

The European crane fly (ECF), Tipula paludosa Meigen feeds on leaves, crowns, and roots of cool-season turfgrasses causing damage to residential lawns and golf courses. A laboratory study was conducted to determine the susceptibility of ECF larvae to four commercial entomopathogenic nematode (EPN) species (Heterorhabditis marelatus, H. megidis, Steinernema carpocapsae and S. feltiae). The virulence of four S. feltiae isolates recovered from golf courses in Quebec and Ontario were also compared to a commercial strain. LC₅₀ values of EPN against late instar ECF larvae were 152, 562, 763, and 3584 for S. feltiae, H. megidis, H. marelatus and S. carpocapsae, respectively. When non-feeding (without grass seedling), ECF larvae mortalities decreased for all nematode species and concentrations tested. At 25°C, LC₅₀ values for the two most virulent indigenous S. feltiae were 129 and 187 nematodes/larva, not different from the commercial strain. At 5°C, the commercial S. feltiae was more effective than both BIC14A and RE6A isolates against ECF larvae. However, at 15°C, BIC14A was the most virulent at the low concentration of 200 IJs/larva.     

苍耳子药物血清对人肝癌细胞增殖的抑制作用

给予体外培养人肝癌细胞苍耳子药物血清,用克隆形成法和流式细胞仪检测对细胞分裂增殖和细胞凋亡的影响。结果表明,苍耳子药物血清(设低、中、高剂量)组和5-FU(5-氟尿嘧啶)组克隆数比对照组克隆数明显减少,克隆形成抑制率分别为18.30%、49.34%、68.12%和53.27%;苍耳子药物血清(低、中、高剂量)组和5-FU组细胞凋亡率分别为:6.1%、8.2%、16.3%和11.3%。苍耳子药物血清对人肝癌细胞分裂增殖具有明显的毒性和抑制作用。     

Differential susceptibility of marine invertebrate larvae: Laboratory predation of sand dollar, Dendrasterexcentricus (Eschscholtz), embryos and larvae by zoeae of the red crab, Cancer productus Randall

Predation on eggs, embryos, and larvae of the sand dollar, Dendraster excentricus (Eschscholtz) was investigated in a series of laboratory feeding experiments. Dendraster susceptibility to predation by zoea larvae of the red crab, Cancer productus Randall was strongly dependent on developmental stage and ontogenetic differences in motility. Clearance rates by C. productus were highest for eggs and averaged 0.551·zoea⁻¹·day⁻¹. Embryos and prism larvae of Dendraster were consumed at an intermediate rate, while pluteus larvae were captured at a relatively low rate. Clearance rates decreased from 0.18 to 0.031·zoea⁻¹·day⁻¹ during the transition of prism larvae into echinoplutei. Differences in Dendraster susceptibility to predation cannot be attributed to increasing prey body size because dwarf plutei were captured at the same rate as normal plutei. Reduced capture rates by Cancer productus zoeae are dependent on the development of Dendraster swimming behavior. Periodic reversals in the direction of ciliary beating and backwards swimming effectively remove Dendraster plutei from the immediate capture sphere of Cancer productus. Reversed swimming appears to function as a post-contact encounter response that reduces the mortality rates of Dendraster plutei.     

The effect of selection with levamisole on benzimidazole resistance in Ostertagia spp. of sheep

A field population of Ostertagia spp. (predominantly O. circumcincta) in sheep, found to be resistant to oxfendazole, was exposed to selection with1 levamisole in the laboratory and the field. Progeny of the survivors of a single dose of levamisole in penned sheep showed a significantly lower level of resistance to oxfendazole in an anthelmintic assay, and a similarly lower level of resistance to the ovicidal activity of thiabendazole in vitro compared with the progeny of the survivors of a single dose of oxfendazole, although they remained more resistant than a known susceptible strain of 0. circumcincta. The progeny of worms present in grazing sheep after three doses of levamisole at 4-weekly intervals, and subjected to the same tests, behaved in a similar fashion. They also showed a substantial fall in benzimidazole resistance compared with the progeny of worms not exposed to any anthelmintic for 6 months. The results suggested that levamisole selected positively against benzimidazole resistance. In these circumstances some form of alternation in the use of different anthelmintics could delay the development of a high level of resistance and maintain the practical usefulness of existing anthelmintics.     

甘肃小苏干湖盐沼湿地盐地风毛菊叶形态-光合生理特征对淹水的响应

盐沼湿地植物叶片功能性状对淹水的响应分析, 有助于探究植物叶片可塑性机制与光合生理特征间的内在关联性, 对深入理解盐沼湿地植物的生境抗逆性策略具有重要意义。根据小苏干湖湖水泛滥区静水持留时间长短分别设置: 轻度淹水区(静水持留30-90天)、中度淹水区(静水持留90-150天)、重度淹水区(静水持留150-210天) 3个试验样地, 以盐地风毛菊(Saussurea salsa)为研究对象, 研究了小苏干湖盐沼湿地盐地风毛菊叶片功能性状对淹水的响应。结果表明: 随着静水持留时间的增加, 轻度淹水区盐地风毛菊形态上采用小比叶面积(SLA)的肉质化小叶模式, 光合生理上具有高实际光合效率(Y(II))和低调节性能量耗散的量子产额(Y(NPQ))的协同变异; 重度淹水区盐地风毛菊形态和光合生理上则采用与轻度淹水区完全相反的协同变异策略; 在3个样地中, SLA与Y(II)、光化学淬灭(QP)和Y(NPQ)间均呈极显著相关关系; 叶绿素a含量和叶绿素b含量与调节性能量耗散的量子产额(Y(NO))均呈显著正相关关系。小苏干湖湖水泛滥区静水时空演变格局影响下, 盐地风毛菊种群通过改变叶面积、叶厚度和SLA等叶片形态特征, 适时调整叶片Y(II)和Y(NPQ)等光合生理特征, 实现植物叶片光合碳同化产物的收支平衡, 表现出对水盐异质性环境较强的耐受性, 反映了盐沼湿地植物在极端生存环境下的叶片可塑性和抗逆性机制。     

Fenitrothion: an alternative insecticide for the control of deltamethrin‐resistant populations of Triatoma infestans in northern Argentina

Deltamethrin‐based campaigns to control Triatoma infestans (Klug) (Hemiptera: Reduviidae) have decreased in success as a result of the development of insecticide resistance. We compared the in vitro effects of the pyrethroid deltamethrin and two doses of the organophosphate fenitrothion, presented on different materials, on T. infestans from La Esperanza, Argentina. Laboratory tests demonstrated a decrease in susceptibility to deltamethrin in the field population [LD₅₀: 30.32 nanograms per insect (ng/i)] compared with the reference population (LD₅₀: 0.13 ng/i), giving a high resistance ratio of 233.42. By contrast, similar susceptibility to fenitrothion was assessed in both the field and reference populations (LD₅₀: 21.65 ng/i and 21.38 ng/i, respectively). The effectiveness of the formulated insecticides varied according to the surfaces to which they were applied. The application of fenitrothion formulations to glass or brick resulted in mortality of 90–100%. The application of fenitrothion formulations to wood or mud caused mortality in the range of 6.7–56.7%. Resistant insects presented low mortality when exposed to the deltamethrin formulation and high mortality when exposed to fenitrothion formulations. Moreover, the insecticides demonstrated residual activity only when applied to glass. The present work demonstrates that fenitrothion is an alternative to pyrethroids for the management of deltamethrin‐resistant insects in La Esperanza. However, this effectiveness is not sustained over time.     

温度对新菠萝灰粉蚧生长发育和繁殖的影响

新菠萝灰粉蚧是近年在我国新发现的一种重要外来入侵害虫,温度是决定新菠萝灰粉蚧能否建立稳定种群的最基本因素.本研究以南瓜作为寄主,探索恒温条件对新菠萝灰粉蚧生长发育和繁殖的影响.在17、20、23、26、29和32 ℃,光周期14L∶10D,相对湿度(75±5)%的实验室条件下,测定了新菠萝灰粉蚧各虫态的发育历期、发育速率、存活率和繁殖力,组建了新菠萝灰粉蚧的实验种群生命表.结果表明: 在20～29 ℃,各虫态的发育历期均随温度的升高而缩短,在20 ℃下雌、雄若虫期的发育历期最长,分别为46.95和50.26 d;29 ℃时雌虫若虫期的发育历期最短,为20.28 d;而雄虫若虫期在32 ℃时最短,为20.70 d.各虫态的温度与发育速率的关系均符合二次回归关系.此外,温度显著影响新菠萝灰粉蚧的存活率,在29 ℃时雌、雄若虫期的存活率均最高,分别为70.3%和69.3%;雌虫世代的发育起点温度为13.80 ℃,有效积温为491.50日·度;雄虫世代的发育起点温度为11.61 ℃,有效积温为388.85日·度.新菠萝灰粉蚧的产卵前期和成虫寿命随着温度的升高而缩短;成虫产卵量在29 ℃时最高,达每雌442.2粒;最小为20 ℃,仅为每雌111.8粒;29和20 ℃下种群趋势指数分别为168.2和19.1,且在17和32 ℃时,新菠萝灰粉蚧1龄若虫和3龄若虫均表现为生长停滞.说明温度过高或过低均不利于其生长发育.温度对新菠萝灰粉蚧的生长发育、存活、繁殖及种群增长有显著的影响,23～29 ℃是最适宜新菠萝灰粉蚧生长发育和繁殖的温度范围.     

Pathogenicity of Heterorhabditis bacteriophora, Steinernema glaseri, and S. scarabaei (Rhabditida: Heterorhabditidae, Steinernematidae) Against 12 White Grub Species (Coleoptera: Scarabaeidae)

We compared the pathogenicity of the entomopathogenic nematodes Heterorhabditis bacteriophora, Steinernema glaseri, and S. scarabaei against third instars of 12 white grub species. The Japanese beetle (Popillia japonica) was highly susceptible to all nematode species. Oriental beetle [Exomala (=Anomala) orientalis], European chafer (Rhizotrogus majalis), Asiatic garden beetle (Maladera castanea), and the May/June beetles Phyllophaga crinita, Ph. congrua, and Ph. (Subgenus Phytalus) georgiana were highly susceptible to S. scarabaei but had mediocre to low susceptibility to H. bacteriophora and S. glaseri. The black turfgrass ataenius (Ataenius spretulus) was very susceptible to H. bacteriophora but had mediocre susceptibility to S. glaseri and S. scarabaei. Northern (Cyclocephala borealis) and southern masked chafer (C. lurida) had mediocre and southwestern masked chafer (C. pasadenae) and green June beetle (Cotinis nitida) had low susceptibility to all nematode species.     

农杆菌介导双孢蘑菇AS2796转化体系的优化

双孢蘑菇Agaricus bisporus是一种药食皆宜的食用真菌,具有极高的经济价值,近年来在双孢蘑菇全基因组测序完成后,功能基因组学的研究逐步提上日程。其中,高效的遗传转化体系作为技术基础成为研究重点。农杆菌介导的遗传转化体系作为一种高效的功能基因组研究方法,在双孢蘑菇中已经得到了广泛的应用,但是仍然存在着效率较低的问题有待解决。为了提高双孢蘑菇的农杆菌转化效率,找到双孢蘑菇遗传转化的最优条件,本实验首先对双孢蘑菇的潮霉素抗性压力进行了筛选,结果显示20mg/L的潮霉素浓度可以抑制菌丝生长,而50mg/L的潮霉素浓度则可以完全抑制菌丝生长。其次,对农杆菌菌株、菌液浓度、乙酰丁香酮浓度、菌丝培养时间以及浸染时间做了L16（4 ⁵）的正交实验,通过对各因素影响的分析,得出对转化效率影响最大的因素为菌丝培养时间和农杆菌菌株,且当菌株为LBA4404、菌液浓度OD₆₀₀=0.8、乙酰丁香酮浓度为100μmol/L、菌丝培养时间为40d、浸染时间为10min时,农杆菌介导的双孢蘑菇遗传转化效率最高。     

Mass rearing history negatively affects mating success of male Anastrepha ludens (Diptera: Tephritidae) reared for sterile insect technique programs

Mating competitiveness and sterility induction into cohorts of wild Anastrepha ludens (Loew) (Diptera: Tephritidae) was compared among wild and laboratory flies reared for use in the sterile insect technique Mexican program. Laboratory flies stemming from an 11-yr-old bisexual strain were either not irradiated, irradiated at 3 krad (low dose), or irradiated at 8 krad. In 30 by 30 by 30-cm Plexiglas cages, where a cohort of laboratory flies (male and female) irradiated at different doses (0, 3, and 8 krad) was introduced with a cohort of wild flies, males and females of each type mated randomly among themselves. Compared with nonirradiated laboratory and wild males, irradiated males, irrespective of dose (3 or 8 krad), induced shorter refractory periods and greater mating frequency in wild females. Nevertheless, laboratory flies irradiated at a low dose induced greater sterility into cohorts of wild flies than laboratory flies irradiated at a high dose. In a 3 by 3 by 3-m walk-in cage, wild males gained significantly more matings with wild females than nonirradiated and irradiated laboratory males a finding that revealed a strong effect of strain on mating performance. Mating incompatibility of the laboratory strain might have obscured the effect of reduced irradiation doses on male mating performance in the walk-in cage. Our results highlight an urgent need to replace the A. ludens strain currently used by the Mexican fruit fly eradication campaign and at least suggest that reducing irradiation doses result in an increase in sterility induction in wild populations.     

Protists and detrital particles as prey for the first larval stage of the brachyuran crab, Hemigrapsus oregonensis

Newly-hatched larvae of the brachyuran crab, Hemigrapsus oregonensis, were raised in the laboratory on an autotrophic dinoflagellate (Prorocentrum micans), a heterotrophic dinoflagellate (Noctiluca milaris), a green alga (Dunaliella tertiolecta), an unfed control, and a fed control of Artemia sp. nauplii. Larvae also were fed preparations of seagrass detritus that had been cultured both to promote microbial colonization and to discourage it. Detrital diets were used both alone and in combination with sub-optimal applications of Artemia sp. nauplii. Larvae raised on P. micans showed survival to zoeal stage II equal to those raised on the Artemia sp. nauplii control, although development was delayed. Larvae raised on N. milaris showed substantial (34.7%) survival to zoeal stage II; however survival was lower and development slower than for Artemia sp. nauplii-fed larvae. Survival on D. tertiolecta was less than 3%. Larvae fed microbially-enriched detritus showed a delay in mortality as compared to unfed controls. No larvae fed solely on detritus survived to zoeal stage II. When larvae were fed a sub-optimal diet of Artemia nauplii, supplemented by detrital particles, survival to zoeal stage II increased, although not to the level shown by Artemia-fed larvae in optimal application. Development was not accelerated over the sub-optimal diet in either treatment. The potential for larval crabs to utilize a wide variety of potential prey immediately upon hatching is significant given their susceptibility to early starvation. Such omnivory also suggests a trophic link between carbon sources of the microbial loop and crab larvae.     

石斛内生炭角菌DNA提取方法优化及分子鉴定

本文对石斛内生炭角菌DNA提取方法进行优化,并基于ITS序列及其ITS2二级结构对其进行分子鉴定。比较试剂盒法及不同浓度（2%、3%、4%）CTAB法的DNA提取效果并对CTAB法进行优化;进行ITS序列的扩增及ITS2二级结构的预测。结果表明：4%的CTAB提取效果最佳,优化的CTAB法大大缩短了DNA提取时间;ITS序列与炭角菌属3个种的相似度均为99%,ITS2二级结构仅与Xylaria arbuscula的二级结构100%相似。本研究所优化的CTAB法能为后续相关研究提供便利;结合ITS序列及ITS2二级结构能对石斛内生炭角菌进行准确的分子鉴定。     

Susceptibility of immature stages of Homalodisca coagulata (Hemiptera: Cicadellidae) to selected insecticides

Susceptibility of immatures of the glassy-winged sharpshooter, Homalodisca coagulata (Say) (Hemiptera: Cicadellidae), to 10 insecticides that included chlorpyrifos, dimethoate, endosulfan, bifenthrin, cyfluthrin, esfenvalerate, fenpropathrin, acetamiprid, imidacloprid, and thiamethoxam was evaluated in the laboratory. All five instars were exposed to different doses of each foliar insecticide by the petri dish technique, whereas a systemic uptake method was used to assess the toxicity to imidacloprid and thiamethoxam. All test insecticides exhibited high toxicity to all immature stages of H. coagulata at concentrations below the field recommended rates of each insecticide. Although all five instars were susceptible to test insecticides, mortality was significantly higher in first instars than in the older immatures based on low LC50 values (ranging from 0.017 to 5.75 ng(AI)/ml) with susceptibility decreasing with each successive stage. Fifth instars were generally the least sensitive (LC50 values ranging from 0.325 to 216.63 ng (AI)/ml). These results show that mortality was directly related to age of the insect and suggest that chemical treatment at early stages is more effective than at late stages. Acetamiprid (neonicotinoid) and bifenthrin (pyrethroid) were the most toxic to all five instars, inducing most mortality within 24 h and showing lower LC50 values ranging from 0.017 to 0.686 ng/ml compared with other insecticides (LC50 values ranging from 0.191 to 216.63 ng(AI)/ml). Our data suggest that a diverse group of very effective insecticides are available to growers for controlling all stages of H. coagulata. Knowledge on toxicity of select insecticides to H. coagulata immatures may contribute to our understanding of resistance management in future for this pest by targeting specific life stages instead of the adult stage alone.     

Pesticide Susceptibility of Two Coccinellids (Stethorus punctum picipes and Harmonia axyridis) Important in Biological Control of Mites and Aphids in Washington Hops

The susceptibility of Stethorus punctum picipes (Casey) and Harmonia axyridis Pallas larvae to pesticides used or with potential for use in Washington hops, was examined in laboratory bioassays. All pesticides tested except the miticide, hexythiazox, the insecticides, chlorpyrifos and pirimicarb, and the fungicide, mycobutanil, produced 100% mortality in S. punctum picipes at concentrations equivalent to field rates. The insecticides, pirimicarb, endosulfan, and thiamethoxam were least toxic to H. axyridis. Bifenthrin, diazinon, dimethoate, methomyl, carbaryl, malathion, phosmet, imidacloprid, and chlorpyrifos were highly toxic. The miticides, abamectin and fenpyroximate were highly toxic, milbemectin was moderately toxic but all other miticides tested were non-toxic. All fungicides had low toxicity. Selection and use of pesticides compatible with natural enemies and conservation biological control in Washington hop production is discussed.     

Comparative study of gamma-ray and high-energy carbon ion irradiation on negative gravitaxis inEuglena gracilisZ

The effects of ⁶⁰Co gamma-ray and 290 MeV/amu carbon ion irradiation on negative gravitaxis was studied in the photosynthetic flagellate Euglena gracilis strain Z in a dose-response dependent manner. Cells were exposed to the doses (0-200 Gy for water). The negative gravitaxis was quantified by the r-value observed in a recently developed biomonitoring system. The present results demonstrate the inhibitory effects of gamma-rays and 290 MeV/amu carbon ions on negative gravitaxis of the Euglena gracilis strain Z. The 290 MeV/amu carbon ions had a greater impact at a low dose (<40 Gy) than the ⁶⁰Co gamma-rays.     

肺形侧耳低温胁迫时期的转录组分析

本文以肺形侧耳栽培菌株X57为研究对象,利用高通量RNA测序技术对4℃低温处理0h、6h和12h后的肺形侧耳进行基因表达分析来探讨肺形侧耳低温应答机制。分析结果筛选出低温处理6h差异表达基因742个,其中上调表达基因374个,下调表达基因368个;低温处理12h差异表达基因1 489个,其中上调表达基因占53%,下调表达基因占47%。Gene Ontology（GO）功能聚类分析表明,差异表达基因主要富集在结合、催化分子功能组和代谢过程、细胞过程生物学过程中。KEGG功能富集分析结果显示,差异基因主要富集在氨基酸、核糖体和类固醇生物合成,及氮类物质代谢的通路上,富集到与低温胁迫相关通路MAPK signaling pathway-yeast上的基因表达随低温处理时间的增加呈上调趋势。已报道HOG-MAPK通路是MAPK途径研究较为明确、信号传递单一的真菌低温胁迫中重要的通路,本文运用生物信息学软件构建肺形侧耳的HOG-MAPK通路,并利用荧光定量PCR对相关基因表达进行验证,结果显示以低温处理0h为参照,随着低温胁迫时间增加通路上大部分基因的表达量持续上升,且差异显著,与RNA‐Seq分析结果一致。本文通过全面分析肺形侧耳低温胁迫时期基因表达情况,为进一步研究肺形侧耳低温胁迫相关重要基因的功能鉴定与信号通路调控机理提供基础。     

Aspects of the life history of Cercopithifilaria johnstoni (Nematoda:Filarioidea)

and 1988. Aspects of the life history of Cercopithifilaria johnstoni (Nematoda:Filarioidea). International Journal for Parasitology 18: 1087–1092. Cercopithifilaria johnstoni (Nematoda:Filarioidea) occurs in the subcutaneous connective tissues of a spectrum of native murid and marsupial hosts in Eastern Australia. Life cycle studies revealed that: (i) microfilaria occur in lymphatic capillaries and extravascular connective tissue of the dermis (= ‘skin-inhabiting’), (ii) ixodid ticks, particularly Ixodes trichosuri, are intermediate hosts in nature, (iii) development from microfilariae to infective third-stage larva occurs only while the tick is off the host, that is, during ecdysis from larva to nymph or from nymph to adult. Transmission of C. johnstoni in a wild population of bush rats (Rattus fuscipes) occurred in summer and winter, and was associated with peaks in the number of larval and/or nymphal stages of ticks on rats. C. johnstoni was transmitted experimentally to bandicoots (Isoodon macrourus, Perameles nasuta), bush rats and laboratory rats (R. norvegicus), indirectly by subcutaneous inoculation of third-stage larvae and directly by tick feeding. The prepatent period was approximately 3 months and the longest duration of microfilariae in the ‘ skin’ was more than 25 months. Dermal and ocular lesions were observed in R. fuscipes. The host-parasite relationship has the potential for development as an inexpensive and practical model for human onchocerciasis.     

Temperature dependent binding of mebendazole to tubulin in benzimidazole-susceptible and -resistant strains of Trichostrongylus colubriformis and Caenorhabditis elegans.

The binding of [³H]mebendazole ([³H]MBZ) to tubulin in benzimidazole-susceptible (BZ-S) and benzimidazole-resistant (BZ-R) strains of Trichostrongylus colubriformis and Caenorhabditis elegans was examined in order to investigate the biochemical changes to tubulin that result in BZ resistance in parasitic and free-living nematodes. In both species the extent of [³H]MBZ binding to tubulin was significantly reduced in the BZ-R strain compared with the BZ-S strain. The decrease in [³H]MBZ binding in the BZ-R strain of each species was the result of a significant reduction in the amount of charcoal stable [³H]MBZ-tubulin complexes and was not related to a change in the association constant of the [³H]MBZ-tubulin interaction. [³H]MBZ binding to tubulin was temperature dependent, reaching maximum levels at 37°C in BZ-S T. colubriformis and 10°C in BZ-R T. colubriformis. Both the BZ-S and BZ-R strains of C. elegans displayed maximum [³H]MBZ binding at 4°C. Resistance ratios derived from the amount of [³H]MBZ binding in the BZ-S and BZ-R strains and in vitro development assays demonstrated that the temperature dependence and extent of drug binding was indicative of BZ resistance status and was species specific in the BZ-S isolates. These results indicate that biochemical differences exist in the binding of benzimidazole carbamates to tubulin in nematode species, and suggest that the susceptibility of the parasitic nematodes to the benzimidazole anthelmintics is the result of a unique high affinity and/or high capacity interaction ofbenzimidazole carbamates with tubulin.     

感染瓜实蝇的曲霉菌及其生物学特性

从海南自然发病死亡的瓜实蝇上分离获得2株高毒力的真菌BC-D1和BC-212,经形态学和ITS序列鉴定结果表明, BC-D1为黄曲霉Aspergillus flavus,BC-212为溜曲霉Aspergillus tamarii。室内毒力测定结果发现：菌株BC-D1和BC-212对瓜实蝇成虫均有很高毒力,而对卵、幼虫及蛹的毒力较低。接种8d后成虫的平均死亡率分别为73.5%和85.1%,卵、幼虫及蛹的死亡率均低于50%。两株菌对黄粉虫、斜纹夜蛾及蚜虫的致病率均很低。生物学特性测定,两菌株具有生长速度快、产孢量大的特性,最适合生长的温度范围为30-35℃;在不同营养成分的培养基上,菌株生长速率、产孢量及菌落颜色存在较大差异。