Control Effect of Sublimed Sulfur Paired with Acaricide on Bee Mites

[Objective] This study aimed to compare the effects of sublimed sulfur and acaricide on controlling bee mites.[Method] Three independent experiments were carried out in the same apiary during 2007-2009.[Results] The results showed that this method is effective in eliminating mites settled on combs or hidden during pupae phase,but not in controlling the mites parasitized on adult bees.The control effect on killing Varroa destructor after treated appeared optimal in the first day and then decreased,and that on killing Tvopilaelaps clareae happened in the second day.The results indicated that the effect would be much better if the bees can be treated 1 time to 2 times again in the following 2-5 days after the first treatment.Back to data pool,we found that the treatment of sublimed sulfur paired with acaricide is effective in controlling V.destructor and T.clareae.[Conclusion] This technique could facilitate the apicultural production in the regions suffered from V.destructor and T.clareae.

不同遗传背景腐烂茎线虫生物学杂交体系构建与验证

为研究不同群体腐烂茎线虫(Ditylenchus destructor)生物学杂交体系的构建方案,分别通过薯片平板杂交法、薯条离心管杂交法、薯块切片打孔杂交法构建3种生物学杂交体系探讨了不同遗传背景线虫群体间杂交产生后代的情况。结果显示,3种杂交构建方案均可以培养成功,不同的是甘薯切片接种法杂交率高、后代数量多,亲本自交数量与其他2种方法相比差异显著,同时甘薯切片法微环境更接近原始寄主状态,操作简便、省时省力,相比甘薯平板打孔法和薯条离心管杂交法更便于线虫在小孔内集中,增加线虫杂交几率。比较不同杂交体系优缺点,认为甘薯切片打孔法所构体系为腐烂茎线虫的生物学杂交试验最佳体系。同时,试验对“DeLY×DeYL”杂交后代进行分子鉴定,验证杂交体系是成功的。该体系的建立可揭示不同地理来源的具有不同遗传背景的腐烂茎线虫群体间杂交在后代遗传背景上表现异质性。该结果可为今后不同遗传背景线虫间进行生物学杂交提供技术指导,并为不同遗传背景线虫的生殖隔离与其他进境检疫性线虫的生物学杂交研究提供参考。

狄氏瓦螨(Varroa destructor)的研究进展

狄氏瓦螨(Varroa destructor)是严重危害西方蜜蜂(Apismellifera)的一种寄生螨,近几年对狄氏瓦螨的研究有了新的进展,本文就血统进化、生理机制、携带病原菌和最新的防治方法等领域作一综述。

不同接种方式对甘薯腐烂茎线虫侵染量的影响

探讨盆栽条件下接种方式对甘薯腐烂茎线虫侵染量的影响,并对甘薯茎叶组织中腐烂茎线虫虫口分布及萌芽甘薯的生育期抗性进行了测定。结果表明,接种块植入甘薯中线虫侵染量最高,每g组织达408条,且症状最严重,茎组织中线虫分布最远到达距茎基部90 mm的茎组织。另外,与对照相比,萌芽甘薯对腐烂茎线虫的生育期抗性显著。本文首次报道甘薯腐烂茎线虫侵染甘薯茎叶组织的最远位置和萌芽甘薯的生育期抗性,不同接种方式对甘薯腐烂茎线虫侵染量影响的研究结果,为阐述通过病害传播途径防治该病害提供了理论依据。

Interpreting the Evil Nature of the Human from Symbolism in The Destruc⁃ tors and Lord of the Flies

War has brought mankind a seething world,and the evil of war has brought western civilization and morality to a dead end.This paper discusses William Golding’s novel Lord of the Flies and Graham Greene’s The Destructors.To have a better under⁃standing of the autho’s thought:war is rooted in the original evil of human nature.In the novel,there is no external binding force,such as ethical,moral,legal and religious control.The original evil of human nature is revealed,and the fierce conflict between civi⁃lization and barbarism is aroused,which are intertwined and manifest themselves through multiple symbolic meanings.Based on the theory of symbolism,the paper will classify the name,objects and characters with symbolic significance that appear in large numbers in two novels,and discuss its symbolic meaning and the function of these symbolic meanings to the development of the theme respectively.In order to better grasp the moral of the novel as a whole,ring the alarm bell for human beings,and cause peo-ple to ponder over the various evils of human beings.

Diagnosis and characterization of the ribosomal DNA-ITS of potato rot nematode(Ditylenchus destructor) populations from Chinese medicinal herbs

The potato rot nematode(Ditylenchus destructor) is a very economically important nematode in agronomic and horticultural plants worldwide. In this study, 43 populations of D. destructor were collected from different hosts across China, including 37 populations from Chinese herbal medicine plants. Obtained sequences of ITS-rDNA and D2–D3of 28S-rDNA genes of D. destructor were compared and analyzed. Nine types of significant length variations in ITS sequences were observed among all populations. The differences in ITS1 length were mainly caused by the presence of repetitive elements with substantial base substitutions. Reconstructions of ITS1 secondary structures showed that the minisatellites formed a stem structure. Ten haplotypes were observed in all populations based on mutations and variations of helix H9. Among them, 3 known haplotypes(A–C) were found in 7 populations isolated from potato,sweet potato, and Codonopsis pilosula, and 7 unique haplotypes were found in other 36 populations collected from C. pilosula and Angelica sinensis compared with 7 haplotypes(A–G) according to Subbotin' system. These unique haplotypes were different from haplotypes A–G, and we named them as haplotypes H–N. The present results showed that a total of 14 haplotypes(A–N) of ITS-rDNA have been found in D. destructor. Phylogenetic analyses of ITSrDNA and D2–D3 showed that all populations of D. destructor were clustered into two major clades: one clade only containing haplotype A from sweet potato and the other containing haplotypes B–N from other plants. For further verification, PCR-ITS-RFLP profiles were conducted on 7 new haplotypes. Collectively, our study suggests that D. destructor populations on Chinese medicinal materials are very different from those on other hosts and this work provides a paradigm for relevant researches.

Identification of a major QTL for Hessian fly resistance in wheat cultivar‘Chokwang’

The Hessian fly(HF,Mayetiola destructor)is one of the destructive pests of wheat(Triticum aestivum L.)worldwide.Resistant cultivars can effectively minimize wheat damage due to this insect pest.To identify new quantitative trait loci(QTL)for HF resistance,a population of recombinant inbred lines(RILs)was developed from a cross between the HF-resistant wheat cultivar‘Chokwang’and susceptible wheat‘Ning 7840’,and phenotyped for responses to HF attack.A linkage map was constructed using 1147 single nucleotide polymorphism(SNP)markers generated from genotyping-by-sequencing(GBS).One major QTL,QHf.hwwg-6 BS,for HF-resistance was identified on chromosome arm 6 BS,which explained up to84.0%of the phenotypic variation and was contributed by Chokwang.Two RILs showed recombination in the candidate interval of QHf.hwwg-6 BS,which delimited QHf.hwwg-6 BS to a 4.75 Mb physical interval between 6,028,601 bp and 10,779,424 bp on chromosome arm 6 BS of IWGSC Chinese Spring reference genome Ref Seq v2.0.Seven GBS-SNPs in the candidate interval were converted into Kompetitive allele specific polymerase chain reaction(KASP)markers.Two of them,KASP-6 B112698 and KASP-6 B7901215,were validated in a U.S.winter wheat panel.KASP-6 B112698 was nearly diagnostic,thus can be used to screen QHf.hwwg-6 BS and pyramid it with other resistance genes in breeding programs.

Breeding the Mite-Resistant Honeybee by Nutritional Crossbreed Technology

Mite （Varroa destructor） is one of the most serious parasite threats to the honey bee （Apis mellifera） reared in China. The beekeepers mainly use the drug to control and kill the mite in the past years, but the honey products may be contaminated and the mite is becoming drug-resistant. The main idea of this paper is to research the possibility of mite-resistant honeybee rearing by nutritional crossbreed. The larvae （Apis mellifera ligustica） are bred with the royal jelly of Apis carana carana, and then the morphological index of the worker generation, genotypic frequency and gene frequency of the MDH Ⅱ, genetic resemblance, and mite resistance are measured. The results show that： compared to the parent workers, the proboscis length, anterior wing area, the total length of the third and fourth dorsal plate of the abdomen, the length of the fourth dorsal plate of the tuberculum, the area of the sixth abdominal segment, and the area of wax mirrors are significantly different, but the differences in the brachium index, dactylus index, and wing claw are not significant. Moreover, there are some mutations in the genotypic frequency and gene frequency of the MDH Ⅱ. The mite resistance of the nutritional crossbreed worker is significantly higher. The morphological, physical, and biochemical characters, genetic resemblance, and the mite-resistant ability of the worker generation can be changed by nutritional crossbreeding. Nutritional crossbreeding can be a new way to breed the honeybee.

Rapid Molecular Identification of Tribolium destructor

In this study, a rapid molecular identification method of Tribolium destructor was established with PCR and PCR-RFLP （polymerase chain reaction-restriction fragment length polymorphism） technology. According to the results, （ 1 ） with PCR method, specific primers were designed based on CO1 gene of T. destructor for PCR amplification, and electrophoresis detection confirmed that PCR method could be used to rapidly and accurately identify T. destructor; （2） with PCR-RFLP method, two pairs of degenerate primers were used to amplify CO1 gene of Tribolium species, PCR products were digested with HindIII and detected by electrophoresis, results indicated that PCR-RFLP method could also be used for rapid identification of T. destructor in quarantine practice.

Preliminary Researches Regarding the Effectiveness of the Formic Acid Treatment on Varroa(Varroa destructor) Found in the Artificially Decapped Bee Brood

The objective of the study was to establish the effect of formic acid on varroa(Varroa destructor),inside the capped brood cells,artificially decapped.The experiments were carried out in 2017-2018 on honeybee colonies infested with varroa(V.destructor),in a research apiary belonging to the Institute for Beekeeping Research and Development in Bucharest.The decapping method in the present researches used the decapping fork to scrape the capped comb,without affecting the brood,in order to open it for an effective treatment.The combined treatment method was applied on honeybee colonies as a whole,as well as on brood combs,without bees,put in a special treatment box.The researches were focused on establishing the mortality level of various stages of varroa in artificially decapped brood,in normal colony and separately,as well as to make observations on the effect of formic acid on viability of capped bee brood,artificially decapped.The results show a high mortality of varroa,especially the protonymphs and deutonymphs stages(over 80%).The main conclusion is that the brood decapping method combined with formic acid treatment could be a useful technique to control varroa infestation,both in brood and honeybees,shortening strongly the treatment duration as compared to the usual treatments,increasing the efficacy of treatment by cutting the life cycle of varroa in brood.

The Comparison of the Control Effect on the Varroa Mite with Different Ways of Raising Management

[Objective] The aim was to o research the control effect to Varroa destructor and Tropilaeplaps clareae whit new raising management methods, and reduce the pollution caused by drug treatment of bee. [ Metkod] We took the method that was replace the hive and comb on test col- onies with the comb Formalin soaking liquid used three days after the dry and sterilization in advance with the hive. The test groups were 10 colonies randomly selected from the disinfected comb in the breeding. This was the first kind of method. The control groups were 10 colonies randomly se- lected by the conventional breeding management methods. From January 20th, statistic analysis on parasitic situation of bees once every month be- tween the two methods, and take corresponding measures to prevent and control the varroa mite according to the varroa mite parasitic number in time, then the control effect of mite between the two methods were compared with. [ Result] The results showed that the first method was better than the second one in V. destructor, the control time of T. clareae delayed about one month [ Conclusion] Good breeding method could restrain I V. destructor and T. clareae parasitism, speeded up the colony development, and reduced the pollution of chemical drugs on bee products, regar- dod as a kind good method of controlling bee mites to make use of the feeding and management technology.

Relationship of Secreted Salivary Protein Variants to Virulence in Hessian Fly (<i>Mayetiola destructor</i>(Say))

Salivary proteins are the initial contact between sedentary insect pests and their host plants. It is expected that one or more salivary proteins mediate the interaction between Hessian fly and wheat, in which a feeding site is established to the benefit of the fly. A survey of 52 loci annotated as insect secreted salivary proteins was conducted in 384 individuals evenly distributed among eight biotypes of Hessian fly (B, C, D, E, GP, L, O, and vH9). Amplicons were sequenced with Illumina, and sequence reads were aligned to the reference sequences from which primers had been designed. Positions of consistent base variation (998 in all) were identified and tabulated by biotype. No varying position was associated with biotype-wide virulence to any one of wheat resistance genes H3, H5, H6, H7/H8, H9, H11, H13, and H26. The multiplate pooling strategy utilized in this study is an effective, affordable way to reveal the genotype of hundreds of individuals at tens of genetic loci.

内蒙古自治区鄂尔多斯市马铃薯腐烂茎线虫种类鉴定研究

0 引言马铃薯腐烂茎线虫(Ditylenchus destructor Thorne)又名甘薯茎线虫,属于侧尾腺纲垫刃目粒线虫科茎线虫属。马铃薯腐烂茎线虫病是国际公认的一种检疫性疾病,是马铃薯重要病害之一。该线虫主要侵染植物地下部分,在没有高等寄生植物的情况下,依靠取食土壤中的真菌维持生存,寄主范围广。近几年,马铃薯腐烂茎线虫危害逐渐上升,可导致马铃薯减产20%~83%,严重时甚至绝收。

Genes important for survival or reproduction in Varroa destructor identified by RNAi

The Varroa mite,(Varroa destructor),is the worst threat to honey bee health worldwide.To explore the possibility of using RNA interference to control this pest, we determined the effects of knocking down various genes on Varroa mite survival and reproduction.Double-stranded RNA (dsRNA)of six candidate genes (Da,Pros26S,RpL8, RpL11,RpPO and RpS13)were synthesized and each injected into Varroa mites,then mite survival and reproduction were assessed.Injection of dsRNA for Da (Daughterless)and Pros26S (Gene for proteasome 26S subunit adenosine triphosphatase)caused a significant reduction in mite survival,with 3.57%±1.94% and 30.03%±11.43% mites surviving at 72 h post-inj ection (hpi),respectively.Control mites injected with green fluorescent protein (GFP)-dsRNA showed survival rates of 81.95%±5.03% and 82.36 ±2.81%,respectively. Injections of dsRNA for four other genes (RpL8,RpL11,RpPO and RpS13)did not affect survival significantly,enabling us to assess their effect on Varroa mite reproduction.The number of female offspring per mite was significantly reduced for mites injected with dsRNA of each of these four genes compared to their GFP-dsRNA controls.Knockdown of the target genes was verified by real-time polymerase chain reaction for two genes important for reproduction (RpL8,RpL11)and one gene important for survival (Pros26S). In conclusion,through RNA interference,we have discovered two genes important for mite survival and four genes important for mite reproduction.These genes could be explored as possible targets for the control of Varroa destructor in the future.

Association of Varroa destructor females in multiply infested cells of the honeybee Apis mellifera

The genetic diversity of Varroa destructor (Anderson &Trueman)is limited outside its natural range due to population bottlenecks and its propensity to inbreed.In light of the arms race between V.destructor and its honeybee (Apis mellifera L.)host, any mechanism enhancing population admixture of the mite may be favored.One way that admixture can occur is when two genetically dissimilar mites coinvade a brood cell, with the progeny of the foundresses admixing.We determined the relatedness of 393 pairs of V.destructor foundresses,each pair collected from a single bee brood cell (n =five colonies).We used six microsatellites to identify the genotypes of mites coinvading a cell and calculated the frequency of pairs with different or the same genotypes.We found no deviation from random coinvasion,but the frequency of cells infested by mites with different genotypes was high.This rate of recombination,coupled with a high transmission rate of mites,homogenized the allelic pool of mites within the apiary.

Genes encoding a group of related small secreted proteins from the gut of Hessian fly larvae [Mayetiola destructor （Say）]

A group of related genes has been isolated and characterized from the gut of Hessian fly larvae [Mayetiola destructor （Say）]. Members in this group appear to encode proteins with secretary signal peptides at the N-terminals. The mature putative proteins are small, acidic proteins with calculated molecular masses of 14.5 to 15.3 kDa, and isoelectric points from 4.56 to 4.88. Northern blot analysis revealed that these genes are expressed predominantly in the gut of Hessian fly larvae and pupae. Two related genes, GIOK1 and GIOK2, were isolated as tandem repeats. Both genes contain three exons and two introns. The intron/exon boundaries were conserved in terms of amino acid encoding, suggesting that they arose by gene duplication. The fact that the frequency of this group of clones in a gut cDNA library higher than that of total cDNA clones encoding digestive enzymes suggested that this group of proteins may perform an important function in the gut physiology of this insect. However, the exact functions of these proteins are as yet known since no sequence similarity could be identified between these proteins and any known sequences in public databases using standard methods.

Varroa destructor mite infestations in capped brood cells of honeybee workers affect emergence development and adult foraging ability

Given recent higher declines in managed Apis mellifera honeybees,which are the most commonly managed bee species around the world(Garibaldi et al.2013),numerous health threats involved in the losses have been received great attention.To date,Varroa destructor mite infestation has become the biggest challenge in commercial beekeeping,which is considered as a thorn stuck in the throat of beekeepers.The Varroa mite threatens bee health by absorbing the fat body and hemolymph of immature and mature bees(Ramsey et al.2019).Varroa mite infestation during the development of worker bees was found to reduce birth weight,influence water content and protein level in hemolymph of newly emerged worker bees,decrease flight performance of drones,change gene expression patterns related to immune system of honeybees,and result in honeybee colony losses(Duay et al.2002;Bowen-Walker and Gunn 2010;Zhang et al.2010;Annoscia et al.2012;Dooremalen et al.2013;Locke 2016).The Varroa mite,as an ectoparasite of the honeybee,prefers living in the sealed brood cells(Bogdanov 2006).Thus,bees are more likely to become hosts of mites in the pupal stage.In this study,we systematically investigated the current impacts of V.destructor infestations on the development from capped larvae to emerged bees.

Changing climate patterns risk the spread of Varroa destructor infestation of African honey bees in Tanzania

Background:Climate change creates opportune conditions that favour the spread of pests and diseases outside their known active range.Modelling climate change scenarios is oftentimes useful tool to assess the climate analogues to unveil the potential risk of spreading suitability conditions for pests and diseases and hence allows development of appropriate responses to address the impending challenge.In the current study,we modelled the impact of climate change on the distribution of Varroa destructor,a parasitic mite that attacks all life forms of honey bees and remains a significant threat to their survival and productivity of bee products in Tanzania and elsewhere.Methods:The data about the presence of V.destructor were collected in eight regions of Tanzania selected in consideration of several factors including potentials for beekeeping activities,elevation(highlands vs.lowlands)and differences in climatic conditions.A total of 19 bioclimatic datasets covering the entire country were used for developing climate scenarios of mid-century 2055 and late-century 2085 for both rcp4.5 and rcp8.5.We thereafter modelled the current and future risk distribution of V.destructor using MaxEnt.Results:The results indicated a model performance of AUC=0.85,with mean diurnal range in temperature(Bio2,43.9%),mean temperature(Bio1,20.6%)and mean annual rainfall(Bio12,11.7%)as the important variables.Future risk projections indicated mixed responses of the potential risk of spreads of V.destructor,exhibiting both decrease and increases in the mid-century 2055 and late-century 2085 on different sites.Overall,there is a general decline of highly suitable areas of V.destructor in mid-and late-century across all scenarios(rcp4.5 and rcp8.5).The moderately suitable areas indicated a mixed response in mid-century with decline(under rcp4.5)and increase(under rcp8.5)and consistent increase in late century.The marginally suitable areas show a decline in mid-century and increase in late-century.Our results suggest that the climate change will continue to significantly affect the distribution and risks spread of V.destructor in Tanzania.The suitability range of V.destructor will shift where highly suitable areas will be diminishing to the advantage of the honey bees’populations,but increase of moderately suitable sites indicates an expansion to new areas.The late century projections show the increased risks due to surge in the moderate and marginal suitability which means expansion in the areas where V.destructor will operate Conclusion:The current and predicted areas of habitat suitability for V.destructor’s host provides information useful for beekeeping stakeholders in Tanzania to consider the impending risks and allow adequate interventions to address challenges facing honey bees and the beekeeping industry.We recommend further studies on understanding the severity of V.destructor in health and stability of the honey bees in Tanzania.This will provide a better picture on how the country will need to monitor and reduce the risks associated with the increase of V.destructor activities as triggered by climate change.The loss of honey bees’colonies and its subsequent impact in bees’products production and pollination effect have both ecological and economic implications that need to have prioritization by the stakeholders in the country to address the challenge of spreading V.destructor.