草蛉滞育的研究进展

草蛉是多种农林害虫的重要捕食性天敌昆虫，在生物防治中具有重要作用。滞育是昆虫应对不利环境条件时，生长发育停滞的一种生理状态，许多草蛉种类存在滞育现象。深入开展草蛉滞育的研究，不仅有助于明确其滞育特征和内在调控机制，也有助于提高草蛉的生物防治效果，促进草蛉的商业化生产和应用。本文归纳总结了1910年以来国内外草蛉科种类的滞育研究文献，介绍了目前已开展滞育研究的草蛉种类及其滞育特征，分析了影响草蛉滞育调控的环境因子，论述了草蛉滞育期间的形态和生理生化变化、分子机制及其滞育后发育生物学，并就滞育在草蛉规模化生产中的应用以及目前草蛉滞育研究中存在的问题进行了讨论，以期为深入草蛉滞育的基础理论研究和促进草蛉的规模化生产应用等提供参考依据。     

丽草蛉滞育预蛹的重要生化物质变化分析

丽草蛉是多种农林害虫的重要捕食性天敌昆虫，能以预蛹进行兼性滞育越冬，该属性对延长丽草蛉的产品货架期、增加产品储备量及促进产品运输具有重要意义。本研究分别测定了丽草蛉非滞育预蛹（1日龄）和滞育预蛹（1日龄、7日龄）体内的总蛋白质、脂类、糖类及醇类等主要生化物质的含量，以及脂肪酶、海藻糖酶、抗氧化酶（超氧化物歧化酶、过氧化物酶、过氧化氢酶）等关键酶的活性变化，比较了非滞育和滞育丽草蛉预蛹体内重要生化物质的差异。结果表明：滞育和非滞育丽草蛉的生理生化特征显著不同，滞育预蛹显著积累蛋白质、脂类、甘油三酯、糖原等能源物质以及甘油、海藻糖等低温保护物质，并且滞育个体的抗氧化防御能力显著增强，这些生理生化变化有助于提高丽草蛉的抗逆性，满足滞育维持期及滞育解除后恢复发育的能量需求，保证滞育个体的发育和存活。结果为解析丽草蛉滞育的生理机制奠定了基础。     

美国白蛾生物学上的几个重要特性

本文对青岛市美国白蛾Hyphandria cunez种群的几个重要生物学特性进行了调查，获得了如下有意义的结果。（1）在生态光周期范围内，该虫显示了一个典型的长日照型昆虫，临界日长为14h 30min。然而在全光条件下，有41.2％的个体滞育；在全暗条件下则有83．7％的个体发育。（2）第1代蛹在自然条件下羽化的结果表明，部分个体的蛹期显著延长，呈现了夏季滞育。（3）滞育蛹置于25℃，LD16：8下滞育能够解除，但死亡率极高。（4）雄虫前翅黑斑的出现是由光周期控制的，只有在短日照下诱导的滞育蛹，滞育解除后羽化出来的雄虫才会出现黑斑。     

光周期对硃砂叶螨滞育影响的研究

供试砂叶螨采自河南省新乡县棉田(35°N)。该种叶螨对光周期的反应属于长日照型,临界光周期在20℃条件下为11.2小时。供试种群在短光照下诱发滞育后,不经低温处理,立即放于长光照30℃下,可全部解除滞育。高温对滞育率有降低的效应,每日10小时光照时间,在20、25和30℃时的滞育率分别为100％、69.2％和49.1％。     

黑纹粉蝶在室外养虫网室中连续繁殖的滞育变化

系统观察了黑纹粉蝶PierismeleteMenetries在室外养虫网室中8个世代的滞育变化。结果表明：？夏季高温和长日照明显抑制了滞育的发生，在日平均气温为27℃的6月份，仅有15．9％的个体进入夏季滞育，在日平均气温29．5℃的7月份，夏季滞育则完全消失。！春季逐渐上升的日长（13h24min～14h21min）配合较温暖的气温（日平均19．1℃），诱导了99．6％的个体进入夏季滞育；秋后逐渐缩短的日长（11h53min～11h20min）配合较低的气温（日平均16．5℃），诱导了100％个体进入越冬滞育。秋季逐渐缩短的日长（14h12min～11h53min）配合较高的气温（日平均27．7℃）和较温暖的气温（日平均22．9℃和18．7℃），能满足大部分个体非滞育的发育。试验结果亦表明，黑纹粉蝶具有在夏季繁殖的潜在能力，虽然这种能力在自然条件下没有表现出来。文章最后讨论了该虫夏季带育诱导的光、温机制的适应意义。     

大草蛉人工饲料的初步研究

大草蛉(Chrysopa septempunctata Wesmael)又名七点草蛉,在我国分布很广,是一种能捕食多种农林害虫的天敌昆虫。大草蛉的食性与中华草蛉不同,其成虫和幼虫均捕食蚜虫及其它昆虫的卵或低龄幼虫,中华草蛉仅幼虫是肉食性的,其成虫则取食植物的花粉、花蜜和蜜腺等。在人工饲养条件下,目前能满足中华草蛉正常生长发育的人工饲料,饲养大草蛉均出现生长发育延迟,幼虫死亡率高,成虫产卵量下降,甚至不能传     

中华草蛉幼虫对西花蓟马若虫的捕食功能反应与搜寻效应

中华草蛉是蓟马的重要天敌,为探明其对西花蓟马的控制效能,在室内开展了中华草蛉幼虫对西花蓟马若虫的捕食功能反应与搜寻效应研究。结果表明,在供试温度下,该捕食功能反应符合HollingII型方程。在相同温度下,中华草蛉幼虫的捕食量随着猎物密度的增加而增大,搜寻效应随着猎物密度的增加而降低。在18～26℃范围内,随着温度的升高,中华草蛉幼虫对西花蓟马若虫的捕食量增加,而在26～34℃范围则有相反的趋势。26℃时捕食数量最大,捕食上限达163.9头。在相同猎物密度条件下,捕食作用率与中华草蛉幼虫密度的关系为E=0.3284P-0.4467,分摊竞争强度与中华草蛉幼虫密度的关系为I=0.8203lgP 0.0038。     

广东美洲斑潜蝇寄生蜂常见种类鉴别

本文记述了采自广东的美洲斑潜寄生蜂７种,包括茧蜂科Ｂｒａｃｏｎｉｄｅ的甘蓝斑潜蝇茧蜂Ｏｐｉｕｓ ｄｉｍｉｄｉａｔｕｓ（Ａｓｈｍｅａｄ）和离潜蝇茧蜂Ｏｐｉｕｓ ｄｉｓｓｉｔｕｓ Ｍｕｅｓｅｂｅｃｋ,以及姬小蜂科Ｅｕｌｏｐｈｉｄａｅ的异角亨姬小蜂Ｈｅｍｉｐｔａｒｓｅｎｕｓ ｖａｒｉｃｏｒｎｉｓ,黄潜蝇釉姬小蜂Ｃｈｒｙｓｏｃｈａｒｉｓ ｏｓｃｉｎｉｄｉｓ Ａｓｈｍｅａｄ,底比斯釉姬小蜂Ｃｈｒｙｓｏｃｈａ     

中华草蛉对棉蚜与棉铃虫的捕食作用研究

中华草蛉捕食棉蚜、棉铃虫卵或幼虫,其功能反应的类型均属HollingⅡ型反应。温度对寻找效应有明显的影响,在35℃条件下,中华草蛉对猎物寻找效应比15℃时高出7倍,比20℃时高8倍。这说明,掌握适宜温度释放草蛉,可提高其捕食作用。根据食性选择试验:中华草蛉最喜食棉蚜,次为棉铃虫卵,其喜食程度并不因猎物数量的增加而转移。     

溴甲烷对灰豆象检疫熏蒸处理试验

应用溴甲烷熏蒸剂对豆类中所携带的灰豆象Ｃａｌｏｓｏｂｒｕｃｈｕｓｐｈａｓｅｏｌｉ（Ｃｈｅｖｒｏｌａｔｅ）进行检疫熏蒸处理试验的结果表明，灰豆象对溴甲烷熏蒸剂耐药性较低。几种虫态相比之下，卵耐药性最低，蛹耐药性最强，而幼虫耐药性程度居于二者之间。在熏蒸处理平均温度为１８℃以下较低温度条件下熏蒸，卵和幼虫１０ｍｇ／Ｌ，１０ｈ；蛹１５ｍｇ／Ｌ、１０ｈ、１０ｍｇ／Ｌ，２４ｈ，其各虫态校正死亡率均可达１００％。在熏蒸处理平均温度为２６．５℃以上较高温度条件下熏蒸，卵５ｍｇ／Ｌ，１０ｈ、３ｍｇ／Ｌ，２４ｈ；幼虫５ｍｇ／Ｌ，２４ｈ及１０ｍｇ／Ｌ，１０ｈ；蛹１５ｍｇ／Ｌ，１０ｈ或１０ｍｇ／Ｌ，２４ｈ，以上各虫态校正死亡率也均可达１００％。     

大草蛉香腺提取物生物活性的观察

用二氯甲烷、正己烷、丙酮、乙醚等有机溶剂提取大草蛉雌成虫香腺分泌物,观察对雄虫的生物活性,研究表明：向含有腺体提取物的滤纸吹风半分钟后,雄虫表现出交配前的行为,迅速朝滤纸一方移动,触角前后晃动,振翅,腹部不断弯曲,震颤。初步认为,香腺即为其性外激素腺体。     

Tomato yellow leaf curl virus effects on chloroplast biogenesis and cellular structure

Tomato yellow leaf curl virus (TYLCV) is a begomovirus causing significant crop losses in tomatoes worldwide. TYLCV infection has several defined symptoms that are characterized at the whole plant level that include yellowing and curling of the leaves, stunting and growth retardation, and severe yield losses that can reach 100%. While the etiology and phenotypic symptoms of TYLCV infection were characterized, little is known about the cellular basis of these symptoms. Our goal in the present study is to describe some of the microscopic features of the disease while comparing TYLCV-susceptible and resistant near-isogenic tomato plants under infection. We depict the cellular changes that occur in susceptible line as a result of TYLCV infection that include: epidermal cell sizes reduction, accompanied with modifications in cell shape; reduction in plastid number, plastid size and chlorophyll content; diminished expression genes encoding LHC, Rub L, CAB4, and CAB8 and a surge in plasmodesmata number after infection. We conclude that TYLCV affect many targets or that it has a very critical target in cellular development.     

Induction of different chitinase andΒ-1,3-glucanase isoenzymes in sunflower (Helianthus annuus L.) seedlings in response to infection byPlasmopara halstedii

Chitinase and-1,3-glucanase activities were assayed in roots, hypocotyls and cotyledons of downy mildewsusceptible and -resistant sunflower (Helianthus annuus L.) cultivars. While the highest-1,3-glucanase activity was in roots, that of chitinase activity was in hypocotyls. Inoculation of both sunflower cultivars withPlasmopara halstedii resulted in a marked increase of chitinase and-1,3-glucanase activities. The increase was observed earlier in incompatible than in compatible reactions. Both enzymes occurred in root tissue as a complex mixture of isoenzymes. At least three different peaks with chitinase activity and three with glucanase activity could be resolved by gel filtration chromatography on Sephacryl S-100 and chromatofocusing on PBE 94 (pH 7-4). Following ammonium sulfate precipitation and ion-exchange on CM- and DEAE-Trisacryl, three glucanase and chitinase fractions, referred to as basic, neutral and acidic, were separated on the basis of their Chromatographic behaviour. A different pattern of distribution of chitinase and-1,3-glucanase fractions was observed between inoculated and non-inoculated plants in both resistant (cv. RS-105) and susceptible (cv. Peredovik) cultivars. In healthy plants-1,3-glucanase was mainly found in the basic (cv. Peredovik) and neutral (cv. RS-105) fractions, whereas chitinase was in the basic fraction for both cultivars. The neutral and acidic fractions of chitinases were induced in the compatible and incompatible reactions. Inoculation of the plants induced the neutral-1,3-glucanase fraction in resistant and susceptible cultivars and the acidic only in the susceptible one. Induction of the basic fraction of both activities was not observed in any case.     

微管、微丝特异性抑制剂处理对水稻抗病性的影响

 微管特异性抑制剂oryzalin、微丝特异性抑制剂细胞松弛素A (cytochalasin A,CA)和细胞松弛素D (cytochalasin D,CD)的试验表明:oryzalin在5~50μmol/L、CA在0.5~1.0μg/mL、CD在1~20μg/mL的浓度范围内,对稻瘟病菌孢子的萌发和附着胞的形成基本上没有影响。采用以上几种细胞骨架特异性抑制剂处理水稻叶鞘都可以不同程度地抑制寄主细胞抗病菌扩展的能力。在抑制剂处理的水稻叶鞘细胞中,病菌扩展的速度加快。进一步的观察发现,抑制剂处理抑制水稻细胞抗病菌的扩展能力与水稻的抗病防卫反应如原生质颗粒化、多酚类物质的积累和HR发生的延迟是相关的。     

Biological control mechanisms of D-pinitol against powdery mildew in cucumber

D-pinitol is an effective agent for controlling powdery mildew (Podosphaera xanthii) in cucumber. In this study, we determined the mechanisms of D-pinitol in controlling powdery mildew in cucumber plants. We compared P. xanthii development on cucumber leaf surface treated with D-pinitol or water (2 mg ml⁻¹) at different time points after inoculation. The germinating conidia, hyphae, and conidiophores of the pathogen were severely damaged by D-pinitol at any time of application tested. The highest level of suppression of fungal development was obtained at 3 days after inoculation. The contents of chlorophyll, total phenolics, flavonoid, and gallic acid and its derivatives (GAD); the activities of phenylalanine ammonialyase (PAL), polyphenoloxidase (PPO), peroxidase (POX), and superoxide dismutase (SOD); and the expression of the genes encoding for PR-1, peroxidase (POX), lipoxygenase (LOX1), chitinase (Chit1) were higher in the cucumber leaves treated with D-pinitol and inoculated than in the leaves either treated with D-pinitol or inoculated with the pathogen. These results suggest that D-pinitol triggers several plant defense responses in cucumber leading to pathogen suppression and resistance to powdery mildew.     

Fungicide responses of maize hybrids to grey leaf spot

Grey leaf spot disease of maize (Cercospora zeaemaydis) has seriously decreased grain yields in the province of KwaZulu-Natal, South Africa, and has spread to infect maize in neighbouring provinces. No commercial hybrids, resistant to the disease have so far been identified, and fungicides have been shown to reduce disease severity. The response of sixty-four commercial hybrids to grey leaf spot under fungicide treatment were studied over two seasons. Overall, fungicides reduced disease severity and linear regression of gain in yield against disease severity enables the identification of hybrids with optimum responses to fungicides. Under low disease levels hybrids responded less to fungicides than under high disease levels. The most susceptible hybrids had the highest responses in control of leaf-blighting and gain in yield. Hybrids with lower-than-predicted leaf-blighting also had lower-than-predicted yield responses, indicating these to be less susceptible to grey leaf spot. These less susceptible hybrids are likely to require fewer fungicide treatments than more susceptible hybrids and are at lesser risk of serious yield losses.Abbreviations GLS grey leaf spot - AUDPC area under disease progress curve     

Oligochitosan induces cell death and hydrogen peroxide accumulation in tobacco suspension cells

Oligochitosan has been shown to induce several plant defense responses. In the present work, the effect of oligochitosan on tobacco cell survival was investigated. The results showed that oligochitosan caused tobacco cell death in a dose-dependent manner. About 40.6 % tobacco cells died when cultured for 72 h after 500 μg ml⁻¹ oligochitosan treatment. Certain aspects of this cell death process appeared to be similar to apoptosis in animal cells. These included shrinkage of cytoplasm and condensation of chromatin. Oligochitosan also induced H₂O₂ accumulation in tobacco cell suspension culture. The role of H₂O₂ in the signal transduction that leads to cell death was investigated. Co-treatment of tobacco cells with oligochitosan and catalase inhibited H₂O₂ accumulation but did not inhibit the induction of cell death. The results suggested that apoptosis-like cell death of tobacco cells induced by oligochitosan is independent of H₂O₂ signal pathway.     

栗真绥螨和黄瓜新小绥螨对西方花蓟马初孵若虫功能反应的比较

于人工气候箱（23±1℃、RH70%±5%、光照（D∶L=16h∶8h）条件下,在菜豆叶片制作的叶碟上,比较了栗真绥螨与黄瓜新小绥螨对西方花蓟马初孵若虫的功能反应。结果表明：黄瓜新小绥螨和栗真绥螨对西方花蓟马初孵若虫的功能反应均符合HollingⅡ型模型,分别为Na=0.763×Nt/（1＋0.152Nt）和Na=0.257×Nt/（1＋0.032Nt）,对西方花蓟马初孵若虫的攻击率分别为0.763和0.257,处理时间分别为0.199d和0.125d,日最大捕食量分别为5.0头和8.0头。     

异色瓢虫对槐蚜的捕食功能反应

在室内条件下,就异色瓢虫对槐蚜的捕食功能反应进行了研究。结果表明,异色瓢虫各龄幼虫、成虫对槐蚜的日捕食量差异较大。在相同槐蚜密度条件下,老熟幼虫和成虫的捕食量要远远高于低龄幼虫;各龄幼虫、成虫的捕食量均随槐蚜密度的增加而增加,当槐蚜增加到一定水平,捕食量趋于稳定。异色瓢虫各龄幼虫和成虫的功能反应均属于HollingⅡ型,经Χ2检验,各圆盘方程理论值和实测值拟合较好。异色瓢虫各龄幼虫、成虫对槐蚜的寻找效应随猎物密度的增加而减少。