赤拟谷盗Tribolium castaneum与锈赤扁谷盗Cryptolestes ferrugineus种间竞争的研究

在30℃、75%RH条件下研究赤拟谷盗Tribolium castaneum与锈赤扁谷盗Cryptolestes ferrugineus的种间竞争,并采用Votka-Volterra种间竞争模型进行拟合。结果表明,赤拟谷盗与锈赤扁谷盗混合饲养时的种群数量均小于单独饲养时的种群数量,两物种之间存在着显著的种间竞争关系。属于资源利用型竞争;单独饲养和混合饲养条件下赤拟谷盗的种群数量均大于锈赤扁谷盗的种群数量;混合饲养条件下两个物种可以共存,并形成稳定的平衡状态,在这个竞争系统中,赤拟谷盗为优势种。

Genome-wide mapping of conserved microRNAs and their host transcripts in Tribolium castaneum

MicroRNAs （miRNAs） are endogenous 22-nt RNAs, which play important regulatory roles by post-transcriptional gene silencing. A computational strategy has been developed for the identification of conserved miRNAs based on features of known metazoan miRNAs in red flour beetle （Tribolium castaneum）, which is regarded as one of the major laboratory models of arthropods. Among 118 putative miRNAs, 47% and 53% of the predicted miRNAs from the red flour beetle are harbored by known protein-coding genes （intronic） and genes located outside （intergenic miRNA）, respectively. There are 31 intronic miRNAs in the same transcriptional orientation as the host genes, which may share RNA polymerase II and spliceosomal machinery with their host genes for their biogenesis. A hypothetical feed-back model has been proposed based on the analysis of the relationship between intronic miRNAs and their host genes in the development of red flour beetle.

Identification,Characterization, and Expression of P450 Gene Encoding CYP6BQ13v2 from the Red Flour Beetle,Tribolium castaneum (Herbst) (Coleoptera:Tenebrionidae)

An allele of CYP6BQI3, named CYP6BQ 13v2 （GenBank accession no. FJ209361）, was isolated from the red flour beetle, Tribolium castaneum （Herbst） （Coleoptera： Tenebrionidae） by RT-PCR. The cDNA sequence of CYP6BQ13v2, 1 563 bp in length, contains an open reading frame of 1 554 nucleotides encoding a putative protein of 518 amino acid residues with a predicted molecular weight of 59.92 kDa and a theoretical pl of 7.60. The putative protein contains the classic hemebinding sequence motif F××G×××C×G （residues 456-465） conserved among all P450 enzymes as well as other characteristic motifs of all cytochrome P450s. It shares 98% identity with the previously published sequence of CYP6BQ13 （GenBank accession no. XP967146） from the T. castaneum genome project. Phylogenetic analysis of amino acid sequences from members of various P450 families indicated that there was closer phylogenetic relationship of CYP6BQ 13v2 with CYP302A1 and CYP307A1 mediating synthesis of the insect molting hormone, distant relationship with CYP6B1 metabolizing plant allelochemicals, CYP6D 1 linking to pyrethroid resistance and other members of CYP6 family. Expression test of the gene in the adults and immature stages of T. castaneum by quantitative real-time PCR revealed that CYP6BQ13v2 is expressed in all life stages investigated. The mRNA expression level in 1st instar larvae was 14.9- and 3.86-fold higher than those in pupae and adults, respectively. The CYP6BQ13v2 expression levels appeared in the order of 1st instar larvae, followed by 4th instar larvae, 7th instar larvae, adult, and pupae from high to low. The more bioinformation of CYP6BQ 13v2 was also analyzed.

Transcriptome analysis of hsp18.3 functions and regulatory systems using RNA-sequencing in the red flour beetle,Tribolium castaneum

The red flour beetle, Tribolium castaneum, is a major agriculture pest of stored grain, cereal products and peanuts for human consumption. It is reported that heat shock protein 18.3 of T. castaneum（Tchsp18.3） plays a significant role in stress resistance, development and reproduction. However, the regulatory systems of Tchsp18.3 remain unknown. Therefore, we compared the global transcriptome profiles of RNA interference（RNAi）-treated larvae（ds-Tchsp18.3） and control larvae of T. castaneum using RNA sequencing. Overall, we obtained 14 154 435 sequence reads aligned with 13 299 genes. Additionally, 569 differentially expressed genes（DEGs） were identified from the ds-Tchsp18.3 and control groups, of which 246 DEGs were annotated in the 47 Gene Ontology（GO） functional groups and 282 DEGs were assigned to 147 Kyoto Encyclopedia of Genes and Genomes（KEGG） biological signaling pathways. The DEGs encoding viperin, dorsal, Hdd11, PGRP2, defensin1 and defensin2 were simultaneously related to immunity and stress responses, which suggests that cross-talk might exist between the immunity and stress responses of T. castaneum. The knockdown of Tchsp18.3 gene expression suppressed the antioxidant activity process, which most likely modulated the effects of Tchsp18.3 on development and reproduction. Furthermore, the DEGs, including Blimp-1, Gld, Drm, Kinesin-14, Pthr2, Delta（11）-like and EGF-like domain protein 2, were also associated with the development and reproduction of ds-Tchsp18.3 insects. Additionally, knockdown of Tchsp18.3 amplified the serine protease（SP） signaling pathway to further regulate stress responses and innate immunity as well as development and reproduction of the red flour beetles. These results provide valuable insight into the molecular regulatory mechanism of Tchsp18.3 involved in insect physiology and further facilitate the research of suitable and sustainable management for pest control.

Resistance of Seven Biscuit Types to Infestation by Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Seven biscuit types namely, Okin, Digestive, Cabin, Peanut, Cream crackers, Hobnobs and Glucose and wheat flour were screened for their resistance to Tribolium castaneum (Herbst) at ambient temperature of 28±2 ℃ and 78±2% relative humidity in the laboratory. 50 g of each biscuit sample were infested with four female and two male adult beetles and left for 15 days then remove for a resistant experiment and 70 days for a mortality experiment. Each treatment and the control without beetles were replicated three times. Results showed that there was significant difference (P<0.05) in the mortality rate of T. castaneum in the biscuit types and wheat flour samples, while there was no significant difference (P>0.05) in the weight loss of biscuit types. The highest adult mortality of beetles (100%) was obtained from Peanut biscuits at 28 days after infestation while there was only 5.5% adult mortality in wheat flour at 70 days after infestation. The susceptibility index was 0 for all the biscuit types since there was no adult emergence indicating that they were resistant to T. castaneum infestation. Resistance in the biscuit types could be due to chemical additives (e.g. sodium chloride and sodium bicarbonate) used in the production of biscuits, which may have inhibitory effect on the development of T. castaneum and also the low moisture content of the biscuits. Packages that can easily be perforated or damaged to allow absorption of moisture from the environment should not be used in packing biscuits.

Resistance of Tribolium castaneum to Phosphine and the Relationship between Complete Lethal Concentration and Exposure Time of Phosphine in Hainan Province

[Objeetive] The paper was to investigate the resistance of Tribolium castaneum to phosphine in Hainan Province. [Method] Using the measurement method of phosphine resistance of stored grain pests recommended by FAO, the phosphine resistance of eight strains of T. castaneum adults in Hainan Province was determined. [Result] The resistance coefficients of different strains of ？7. castaneum against phosphine ranged from 612 to 1 045, and all strains reached extremely high resistance level （Rf〉 160）. When the concentration of phosphine was 200 mL/m^3, Rf612, Rf826.4 and Rfl 045 strains had complete lethal time of 8, 9 and 11 d, respectively. [Condusion] T. castarveum in Hainan Province had very strong resistance to phosphine, and the operation scheme of low concentration and long duration should be adopted in elimination of T. castaneum.

Mortality of Nile Crocodile (<i>Crocodylus niloticus</i>) Eggs Caused by the Flour Beetle (<i>Tribolium castaneum</i>)

It is estimated that quarter to half a million specimens of the Nile crocodile (Crocodylus niloticus Laurenti, 1768) live in liberty. Ranching crocodiles for their skins has been successfully implemented in several African countries but also in Israel. Recently, in one of these ranches, an increased mortality of crocodile eggs was observed and it was thought that insects were causing their death. Two crocodile eggs were kept together with 100 adults of Tribolium castaneum (Herbst, 1797), while the third egg was kept without beetles. No food for beetles was added to the boxes. The eggs were observed twice a month for any kind of changes on their surface. After two months, at least 39 holes were observed in one egg and 146 on the second egg, which was exposed to beetles, while no holes could be seen in the control egg. Some of the holes were deep enough to see the inner layers of the egg. There is enough evidence to believe that adults of T. castaneum are able to damage the eggs of the Nile crocodile and in some cases lead to their death;measures should be taken to protect the eggs from this and similar species of beetles.

The influence of different heating rates on mortality of Tribolium castaneum(Herbst)(Coleoptera: Tenebrionidae)

In order to elucidate the ability of stored product insects to resist high temperature at varying temperature conditions,the influence of different heating rates on the mortality of all life stages of Tribolium castaneum(Herbst)(Coleoptera:Tenebrionidae)was investigated.After acclimation from 28 to 42,44 and 46℃ at different heating rates(0,1.25,2.50,5.00,and 10.00℃/h),eggs,larvae,pupae,and adults of T.castaneum were exposed at 50℃ for 0(as a control),10,15,20,25 and 30 min,respectively.The corrected mortality of T.castaneum was determined after 24 h.The results showed that different exposure times and heating rates had significant effects on the mortality of T.castaneum.The mortality of all life stages of T.castaneum with the same acclimation experience increased significantly with the increasing exposure time,and acclimation improved the heat tolerance of T.castaneum.The mortalities exposed at 50℃ for 30 min of T.castaneum eggs(acclimated to 46℃ at 5.00℃/h),larvae(acclimated to 44℃ at 2.50℃/h),pupae(acclimated to 46℃ at 5.00℃/h),and adults(acclimated to 46℃ at 2.50℃/h)were 62.50%,54.44%,58.89%and 53.33%,respectively,significantly lower than that of corresponding life stages of T.castaneum acclimated at 1.25 and 10.00℃/h.The present results are in favor of developing an effective heat treatment protocol for pest control.

Bioefficacy of Ethanolic Leaves Extract of Azadirachta indica Against Stored Product Insect Pest, Tribolium castaneum (Herbst.)

Tribolium castaneum is a species of beetle in the family tenebrionidae,the darkling beetle.Conventional insecticides used for controling stored product pests are expensive and are proven to have side effects hence the need to have an alternative biopesticides from plants which are proven to be effective against many insects.Azadrachta indica has been used for the control many insects,literature review show no report of its effects on Tribolium castaneum.This study is aimed at evaluating the bioinsecticidal activity of ethanolic leaves extract of Azadirachta indica against stored Tribolium castaneum.Different concentrations(60,70,80,90,and 100%)of ethanolic leaves extract of A.indica was applied on the filter paper and were allowed to dry.Control was done by applying water only on the filter paper.For the determination of the percentage mortality,15 adults of the insects was taken into the Petri dishes embedded with the filter paper covered with a lid.The A.indica extracts at different concentrations tested showed significant insecticidal activity against T.castaneum.Secondary metabolites screening indicated that the A.indica extract have secondary metabolites that are related to insecticidal activity.The study has shown that the ethanolic leaves extract A.indica is effective in managing stored product pest.

肉桂醛对赤拟谷盗的熏蒸作用及对成虫保护酶活性的影响

为明确肉桂醛对赤拟谷盗Tribolium castaneum各发育阶段的杀虫活性及对成虫几种保护酶活性的影响,本试验采用三角瓶密闭熏蒸法测定了肉桂醛对赤拟谷盗低龄幼虫、高龄幼虫、蛹和成虫的熏蒸作用及24 h致死中浓度熏蒸后成虫体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性。结果表明,肉桂醛的熏蒸效果与其浓度和赤拟谷盗发育阶段有关,肉桂醛2.5μL/L熏蒸72 h对赤拟谷盗成虫的熏蒸效果最好,幼虫次之。在24 h致死中浓度处理下,赤拟谷盗成虫体内SOD、POD、CAT活性分别在48、12 h和36 h达到最高,其活性分别为对照的2.70、1.03倍和1.96倍。随着熏蒸时间的延长,成虫POD活性在处理36 h后低于对照,SOD、CAT活性分别在处理36~60 h和24~48 h显著高于对照。综上所述,经肉桂醛熏蒸处理后,赤拟谷盗成虫体内动态平衡受到破坏,进而产生毒害作用。因此,肉桂醛对赤拟谷盗的生物防治有较高的应用价值。

21个高油酸花生品种(系)对赤拟谷盗的抗性鉴定

为探究高油酸花生对赤拟谷盗的抗性情况,本研究以21个高油酸花生品种(系)为材料,按0~4级花生籽仁受害标准,对花生籽仁的虫情指数、相对虫情指数及相对抗虫指数进行测定。结果表明,21个花生品种(系)虫情指数为0.49~37.36,相对虫情指数为0.01~1.00,相对抗虫指数为0~0.99,鉴定出高感、感、抗、中抗、高抗材料分别为2、4、2、8、5个。生化品质与抗虫性相关分析发现,花生籽仁相对抗虫指数与蔗糖含量、可溶性总糖含量及棕榈酸含量呈显著负相关。本研究所用品种(系)不仅具备高油酸特性,而且具有高产特性,有望育成抗仓储害虫的高油酸高产花生新品种,为花生抗仓储害虫育种提供了优异的亲本材料。

氮气气调与脱氧剂联合处理对赤拟谷盗存活的影响

为明确不同氮气体积分数与脱氧剂联合处理对重要储粮害虫赤拟谷盗各虫态的控制效果,研究了赤拟谷盗的卵、幼虫、蛹和成虫在氮气体积分数78%(对照组)、92%、96%和98%的条件下,分别加入0、0.012、0.024、0.048 g/L的20脱氧剂处理2、4、6、8 d后的存活情况。结果表明:氮气体积分数、脱氧剂剂量和处理时间对赤拟谷盗死亡率有显著影响;在相同脱氧剂剂量处理下,赤拟谷盗各虫态死亡率随氮气体积分数和处理时间增加而增加;在相同氮气体积分数条件下,赤拟谷盗各虫态死亡率随处理时间增加而增加;在相同处理时间下,赤拟谷盗各虫态死亡率随氮气体积分数增加而增加;在氮气体积分数92%、96%和98%条件下,当脱氧剂处理剂量为0.012 g/L时,赤拟谷盗各虫态致死时间最短。总体上脱氧剂与氮气气调联合处理杀虫效果高于单独氮气气调处理。

2种植物提取物对杂拟谷盗的生物活性及几种酶活性的影响

杂拟谷盗(Tribolium confusum)是一种重要的储粮害虫,熏蒸是目前主要的防治方法。相比化学熏蒸,植物源杀虫剂作用方式多样且对环境和粮食安全。因此本论文研究了2种植物[瑞香狼毒(Stellera chamaejasme L.)根石油醚提取物和百里香(Thymus mongolicus Ronn.)甲醇提取物]对杂拟谷盗的熏蒸、拒食和驱避活性,以及对杂拟谷盗2种靶标酶和3种解毒酶活性的影响。结果表明,瑞香狼毒根石油醚提取物和百里香甲醇提取物熏蒸杂拟谷盗24 h后,致死中浓度(Lethal concentration,LC 50)分别为88.50和119.57 mg·L^(-1);拒食处理杂拟谷盗5 d后的拒食中浓度(Antifeedant concentration,AFC 50)分别为23.00和14.78 mg·L^(-1);4 h的驱避率分别为63.49%和71.90%。2种植物提取物对杂拟谷盗乙酰胆碱酯酶和三磷酸腺苷酶活性均有抑制作用。2种植物提取物处理杂拟谷盗后,细胞色素P450和谷胱甘肽-S-转移酶活性被诱导升高,而羧酸酯酶活性降低。本试验结果为未来进一步开发利用这2种植物源农药防治储粮害虫提供了一定的理论基础。

大黑粉盗与赤拟谷盗和锈赤扁谷盗对磷化氢的耐受力比较研究

潜在危害的储粮害虫大黑粉盗Cynaeus angustus研究缺乏,掌握其磷化氢耐受力有助于科学治理。采用快速击倒和FAO推荐方法测定了磷化氢对大黑粉盗的KT_(50)值和毒力方程,并与赤拟谷盗Tribolium castaneum和锈赤扁谷盗Cryptolestes ferrugineus进行了比较,测定了100、200、300、400、500 mL/m^(3)磷化氢体积分数下3种害虫卵、幼虫、蛹和成虫不同时间的死亡率。磷化氢对大黑粉盗、赤拟谷盗和锈赤扁谷盗的KT 50值分别为7、127、3736 min,相应毒力方程斜率值(b)为3.67、8.28和9.94,相应LC 50值为0.008、1.34和5.88 mg/L。不同害虫虫态在100~500 mL/m^(3)下的半数致死时间LT 50值于大黑粉盗卵为4~2 h、幼虫4~1 h、蛹4~1 h、成虫3~1 h,于赤拟谷盗为卵12~5 d、幼虫11~5 d、蛹13~7 d、成虫10~4 d,于锈赤扁谷盗为卵28~13 d、幼虫为18~9 d,蛹26~11 d,成虫17~9 d。相应的完全致死时间(LT_(100))于大黑粉盗卵为21~6 h、幼虫8~3 h、蛹9~6 h、成虫5~3 h,于赤拟谷盗卵为21~18 d、幼虫21~15 d、蛹27~18 d、成虫21~12 d,于锈赤扁谷盗卵为54~30 d、幼虫42~30 d、蛹48~30 d、成虫36~25 d。所测大黑粉盗为磷化氢敏感品系,其各虫态对磷化氢的耐受力为卵>蛹>幼虫>成虫,其耐受力远小于赤拟谷盗和锈赤扁谷盗磷化氢抗性品系。

赤拟谷盗在小麦粮堆内部分布特征研究

利用新型害虫探管诱捕器,采集分析赤拟谷盗在试验仓内小麦粮堆中的活动和分布情况,探究其在粮堆内的分布规律及主要影响因素,建立虫口密度评估方程,为其准确监测预警提供科学依据。结果表明:赤拟谷盗的每日捕获数不会随时间出现明显变化。当虫口密度较小时,赤拟谷盗主要在粮堆内的顶层和中层聚集分布;当虫口密度较大时,赤拟谷盗在粮堆内均匀分布。赤拟谷盗表现出趋温性和趋湿性,其适宜活动的温度为22~30℃,相对湿度为40%~53%。综合分析害虫时空分布的规律以及温度、湿度的影响,可根据探管透捕器捕获害虫数量对实际虫口密度做出估算,其虫口密度评估方程为:y=10.566-0.321×x_(1)-0.017×x_(2)+0.026×x_(3),x_(1)为温度(℃)、x_(2)为相对湿度(%)、x_(3)为捕获数(头)。

基于非靶向代谢组学探究扁柏精油对赤拟谷盗的作用机制

扁柏精油对赤拟谷盗具有较强控制作用,通过非靶向代谢组学技术从代谢层面探究其对赤拟谷盗的影响。利用LC-MS技术分析扁柏精油处理后的赤拟谷盗与对照组代谢物的差异。扁柏精油能够影响赤拟谷盗的代谢过程,共鉴定出262个差异代谢物(上调230个,下调32个),主要涉及氨基酸类相关化合物、萜类化合物、生物碱、苯丙酸类、聚酮化合物、脂肪酸相关化合物和黄酮类化合物。这些差异代谢物在35条KEGG代谢途径(包括氨基酸代谢、脂代谢、碳水化合物代谢、辅因子和维生素代谢、信号转导等)中显著富集。本研究为进一步认识扁柏精油对赤拟谷盗的潜在代谢影响提供了依据,并为开发更有效的昆虫控制策略奠定了基础。

赤拟谷盗与杂拟谷盗侵染对小麦粉挥发性物质的GC-IMS分析

目的本研究旨在探究赤拟谷盗(Tribolium castaneum)与杂拟谷盗(Tribolium confusum)侵染对小麦粉中挥发性物质的种类、含量和成分的影响。方法采用气相色谱-离子迁移谱技术(Gas Chroma-tography-Ion Mobility Spectrometry,GC-IMS),对正常小麦粉、受赤拟谷盗与杂拟谷盗侵染的小麦粉进行定性定量测定。结果在3种小麦粉中共检测到了50个峰,鉴定出了41种挥发性物质。赤拟谷盗侵染后,小麦粉中含有高浓度的己醛、2-乙基己醇、壬醛、2,6-双甲基吡啶、(E)-2-庚烯醛、1-辛烯-3-酮、二甲基三硫化合物、庚醛、糠醛。而杂拟谷侵染后小麦粉中则含有高浓度的1-戊烯-3-醇、己醇、2-庚酮、戊醇、3-甲基丁醇。与对照组相比,受两试虫侵染后,小麦粉中的醛类与醇类含量显著增加。结论通过对小麦粉中挥发性物质的分析,并结合气相色谱-离子迁移谱、指纹图谱和主成分分析揭示了正常小麦粉与经过赤拟谷盗与杂拟谷盗侵染的小麦粉中挥发性成分的差异,该研究结果为预测小麦粉储存过程中早期害虫发生提供了参考依据。

Repellent and Fumigant Effects of Essential Oil from Clove Buds Syzygium aromaticum L. against Tribofium castaneum （Herbest） （Coleoptera： Tenebrionidae）

Essential oil from clove buds Syzygium aromaticum L. Merr. ＆ Perry （Myrtaceae） was extracted using petroleum ether in Soxhlet apparatus. The resultant oil contained eugenol （48.92%）, caryophyllene （18.55%）, α-caryophyllene （3.25%）, eugenol acetate （23%）, cis-13-docosenamide （3.2 1%）, presenting more than 96% of the oil. This oil was examined as a fumigant and repellent agent against adults of the red flour beetle, Tribolium castaneum. Data showed that various concentrations of the oil have revealed dramatic repellent activity against the tested insect, where it gave 100% repellency by 1.0, 0.8, and 0.2% clove oil at 4, 8, 10 min, respectively. The RTs0 and RT95 were 1.1 and 8.0 min at 0.2% and 0.4, 2.6 min at 0.8%, respectively. In addition, fumigation assay has also exhibited strong fumigant activity toward the adults of T. castaneum. At 100 μL oil/L air, mortality was 75, 80 and 100% after 6, 7, and 8 days exposure period with LCs0 and LC95 17 and 70 μL/L air, respectively. The utilization of clove oil for its potential effects against stored product insect is discussed.

Prevalence of Wolbachia in 10 Tenebrionidae stored-product insects and spatiotemporal infection dynamics in Tribolium confusum(Jaquelin Du Val)(Coleoptera:Tenebrionidae)

Insect symbionts Wolbachia used for pest population control has focused on vector pest species and agricultural insects while rare reports in Chinese stored-product insect samples.In this paper,we surveyed the prevalence of Wolbachia using a PCR detection method in ten Tenebrionidae stored-product insects.Subsequently,the spatiotemporal Wolbachia infection dynamics in Tribolium confusum and Wolbachia elimination patterns using tetracycline treatment were investigated in detail by TaqMan®probe real-time quantitative PCR,and host reproductive fitness parameters were compared.T.confusum was the only Wolbachia infected species in all the surveyed species.Wolbachia infection density consistently increased with the development of T.confusumand plateaued at 3.7×107 wsp copies per individual insect at the young adult stage.Wolbachia densities in females were higher than that in males with a significant difference at the pupae stage and varied among different tissues and organs.Uninfected female beetles were completely incapable of producing mature progenies when crossed with Wolbachia infected males.Embryogenesis and egg hatch rate were specifically inhibited after Wolbachia elimination,while other traits,including the number of eggs,pupation rate and sex ratio,remained unaffected by tetracycline treatment.Our results showthat the TaqMan®probe qPCR is a reliable detection method for quantifying the density of Wolbachia as compared to qualitative detection of wsp gene by PCR and relatively quantified by real-time qPCR.The fitness results indicated that Wolbachia infection was not an obligate symbiont and benefited the host confused flour beetle.