柑橘大实蝇羽化出土及橘园成虫诱集动态研究

【背景】柑橘大实蝇是柑橘类果树上的重要害虫。预测该虫的羽化出土进度、掌握成虫发生动态是指导橘同成虫期防治的重要依据。【方法】本研究通过在25℃恒温、室内常温和室外网室3种条件下饲养柑橘大实蝇的蛹,以逐日观察成虫羽化出土数量;在重庆武隆、四川江油等5个地区共设置240个麦克菲尔（MePhail）诱集器,以糖酒醋液和水解蛋白为诱饵诱集成虫,得到柑橘大实蝇成虫羽化出土的逐日数量和橘园成虫诱集的逐期数量。【结果】用逻辑斯带模型拟合成虫羽化出土和橘园成虫诱集动态,结果表明,成虫的始盛期、高峰期和盛末期在25℃恒温条件下分别为4月25日、28日和30日,盛期的持续时间为6d;在室内常温条件下分别为5月3日、7日和10日,盛期的持续时间为8d;在室外网室条件下分别为5月8日、14日和18日,盛期的持续时间为11d;橘园诱集成虫分别为6月2日、14日和26日,盛期的持续时间为25d。【结论与意义】随着羽化期温度的提高,柑橘大实蝇羽化出土期提前,历期缩短,羽化整齐。虽然网室成虫羽化和橘园成虫诱集都处于室外条件,但后者的始盛期、盛期和盛末期比前者分别迟了36、30和22d。因此,建议采用室外网室饲养蛹的方法监测柑橘大实蝇成虫的发生期,若仅凭橘园诱集成虫的数据,因其滞后性十分明显,对指导柑橘大实蝇成虫防治的意义不大。     

柑橘大实蝇成虫的梳理行为

【目的】明确柑橘大实蝇Bactrocera minax成虫梳理行为规律,为挖掘防控柑橘大实蝇的新靶标,制订有效的害虫绿色防控策略提供理论依据。【方法】采用录像技术和基于计算机视觉识别技术的柑橘大实蝇成虫梳理行为检测与统计系统,对柑橘大实蝇成虫梳理行为的特征图谱、单次平均耗时和频次占比进行分析。【结果】结果表明,柑橘大实蝇雌雄成虫的梳理行为类型可以分别分为9和8种,雌雄成虫均有前足、后足、复眼、触角、口器、腹部、翅和中足的梳理, 雌成虫还有产卵器梳理行为。柑橘大实蝇成虫可以从非梳理行为随意转入所有类型的梳理行为,或者从任一类型梳理行为转入非梳理行为。在柑橘大实蝇成虫的各类型梳理行为之间的频次占比和单次平均耗时均存在显著差异。其中雌雄成虫梳理前足的频次占比(♀: 33.70%±2.53%; ♂: 33.89%±2.43%)和梳理翅的单次平均耗时(♀:15.58±2.55 s; ♂: 24.76±4.12 s)均为最高。【结论】柑橘大实蝇成虫各类型梳理行为的时间序列并不固定,但这些梳理行为之间具有一定的内在联系。     

柑橘大实蝇成虫复眼的感光作用

【目的】分析柑橘大实蝇Bactrocera minax(Enderlein)成虫复眼的感光作用,为灯光诱杀柑橘大实蝇的绿色防控措施的开发和应用提供理论依据。【方法】本研究利用室内视觉行为实验方法测定遮蔽单眼、遮蔽复眼和同时遮蔽单复眼处理后不同日龄的柑橘大实蝇成虫在不同光强刺激下的趋光行为反应。【结果】与CK(未作任何遮蔽处理)相比,遮蔽复眼处理的成虫的趋光率显著降低,而遮蔽单眼处理的成虫的趋光率则基本不变。遮蔽复眼处理后的1日龄、5日龄和同时遮蔽单复眼处理后的3日龄的雌、雄成虫之间对于1 000 lx光照度的趋光率存在显著差异。不同日龄(1、3和5日龄)的成虫之间对于1 000 lx和2 000 lx光照度的趋光率均存在一定的差异。不同光强(500、1 000和2 000 lx)刺激对成虫的趋光率均有一定影响。【结论】成虫的趋光率与复眼、日龄、性别和光照强度均有关系,其中复眼的作用最明显。     

柑橘大实蝇成虫在中国板栗雄花花序上的取食行为

【目的】证实并探明柑橘大实蝇Bactrocera minax成虫在中国板栗Castanea mollissima雄花花序上的取食行为,从而为柑橘大实蝇的非化学防控提供理论依据。【方法】采用录像技术对柑橘大实蝇成虫在中国板栗雄花花序上的行为活动过程进行跟踪观察和分析。【结果】柑橘大实蝇成虫在中国板栗雄花花序上的取食行为分为爬行、取食、梳理和静息4个阶段,成虫的取食行为没有固定次序,除无法从静息阶段直接到取食阶段外,成虫可从爬行、取食、梳理和静息4个阶段中的任一阶段随意转入另一阶段。成虫取食行为各个阶段的频次占比由高到低排列顺序为:爬行取食梳理静息。静息阶段平均耗时显著超过取食、梳理和爬行阶段;取食、梳理和爬行阶段之间的平均耗时无显著差异。柑橘大实蝇雌成虫与雄成虫之间,各个阶段频次占比和平均耗时均无显著差异。【结论】结果证实柑橘大实蝇雌雄成虫在中国板栗雄花花序上存在取食行为。     

柑橘大实蝇觅食高峰期成虫量与产卵痕率的关系模型研究

【目的】通过研究柑橘大实蝇Bactrocera minax觅食高峰期成虫发生量与产卵痕率的关系,为柑橘大实蝇的预测预报和综合防治提供理论指导。【方法】通过调查柑橘大实蝇觅食高峰期在全田、橘园、杂树林、橘园与杂树林交界带和橘园中心的诱虫量和产卵痕率,建立二者在不同观测区域上的回归方程,为根据柑橘大实蝇觅食高峰期成虫发生量来预测产卵痕率,进而根据产卵痕率确定成虫期防治指标提供理论基础。【结果】除了果园周边杂树林中柑橘大实蝇觅食高峰期成虫诱捕量的线性回归与非线性回归的分析均不理想,不适宜用于产卵痕率的预测外,其他观测区域柑橘大实蝇觅食高峰期成虫诱捕量与果实产卵痕率建立的线性回归与非线性回归方程的拟合效果好,可以作为产卵痕率的预测模型。但不同区域的拟合效果存在差异,其中橘园中心成虫量与产卵痕率回归方程拟合效果(R~2=0.957 5,RMSE=1.623)最好,其他依次分别是:整个橘园成虫量(R~2=0.945 4, RMSE=1.859),全田成虫量(R~2=0.898 2,RMSE=2.535),交界带成虫量(R~2=0.851 5,RSME=3.038)。【结论】这些回归方程均能够较好的预测产卵痕率。考虑到防治需要,可以在橘园中心设置诱捕点,以觅食高峰期的成虫量(x)预测产卵痕率(y),y=0.031 3x~3-1.306 5x~2+17.206 0x-17.036,达到为柑橘大实蝇预测预报和综合防治提供理论指导的目的。     

柑橘大实蝇不同扩散阶段成虫对糖和蛋白的需求及其生殖发育节点与繁殖动态

【目的】针对柑橘大实蝇Bactrocera minax的特殊巡回扩散模式，通过研究不同日龄成虫(特定扩散阶段成虫)对蔗糖和蛋白的营养需求以及其精巢、卵巢发育进度和特定扩散阶段的交配产卵动态，明确柑橘大实蝇不同扩散阶段演替的营养基础与生殖发育节点，初步明晰其巡回扩散机制，为柑橘大实蝇成虫精准防控提供依据。【方法】测定各扩散阶段柑橘大实蝇雌雄成虫对蔗糖和蔗糖+酵母混合食物(蔗糖∶酵母=3∶1, m/m)(酵母的主要成分是蛋白质和维生素)的取食量，测定不同扩散阶段成虫对糖和蛋白的需求；解剖成虫卵巢和精巢；观察成虫交配产卵动态；分析其启动扩散的发育基础和节点。【结果】柑橘大实蝇外迁期(1日龄)和返迁前期(15日龄)雌成虫较其他扩散阶段雌成虫对蔗糖有显著高的取食量，外滞期(10日龄)雌成虫则对糖的取食量最小；迁动状态下，雄成虫对蔗糖的取食量显著低于雌成虫。柑橘大实蝇10日龄雌成虫的酵母摄入量最高，雄成虫则在1, 10和30日龄对酵母摄入量高于15和20日龄雄成虫。10日龄雌成虫、10日龄雄成虫、20日龄雄成虫和30日龄雄成虫对蔗糖+酵母混合食物的取食量显著高于对单一蔗糖的取食量；1, 15和20...     

柑桔大实蝇辐照成虫对两种引诱剂的敏感性

为了明确柑桔大实蝇Bactrocera minax (Enderlein)辐照成虫和田间自然发生的成虫对引诱剂的敏感性差异,指导柑桔大实蝇辐照不育技术的有效利用,在田间释放柑桔大实蝇辐照成虫,以常用引诱剂桔丰和果瑞特同期进行诱集监测。监测结果显示,辐照显著降低了柑桔大实蝇成虫对桔丰和果瑞特的敏感性。在柑桔大实蝇成虫发生高峰期桔丰诱集到辐照成虫的数量仅为诱集总虫量的2.6%-11.6%,果瑞特为5.0%-50.0%;桔丰诱集到的辐照雌性成虫的数量仅为诱集的所有雌性成虫数量的4.4%-11.8%,果瑞特为33.7%-50.0%;桔丰诱集到的辐照雄性成虫的数量仅为诱集的所有雄性成虫的5.3%-11.4%,而果瑞特始终未能诱集到辐照雄性成虫。此外,辐照缩短了柑桔大实蝇成虫对常用引诱剂趋向性的持续时间。研究结果对柑桔大实蝇辐照不育技术与诱集诱杀技术的协调应用具有重要指导意义。     

临海柑橘园橘小实蝇种群数量消长规律

【背景】近年来,随着种植结构的改变以及南方携虫水果的频繁调运,橘小实蝇逐渐向北扩散危害,对水果生产造成严重威胁。【方法】2008～2010年应用性诱剂的监测方法对柑橘园橘小实蝇种群数量进行了定点、系统的跟踪监测;并结合气象资料和田间调查情况,通过对当旬成虫数量与当旬及其前延逐句气象要素的筛选来建模,进而确定影响橘小实蝇种群数量的主要气象因子。【结果】临海柑橘园橘小实蝇种群数量时序变化呈单峰型曲线,其性诱成虫初见期在6月下旬至8月初,高峰期在9月上旬至11月上旬,11月中旬后成虫数量逐渐下降,到12月下旬未诱集到成虫。气象因子筛选和建模结果表明,柑橘园橘小实蝇成虫种群数量年度变动以旬平均温度为决定要素,季节性变化以旬降雨量为决定要素。【结论与意义】临海柑橘园橘小实蝇种群数量随温度和土壤湿度的增大而增长。本研究对提高橘小实蝇监测预警水平、有效控制橘小实蝇危害具有重要意义。     

柑橘大实蝇内参基因的评估

【目的】柑橘大实蝇Bactrocera minax (Enderlein)是一种危害严重的柑橘害虫。本研究旨在筛选柑橘大实蝇在特定条件下体内稳定表达的内参基因, 以确保使用实时荧光定量PCR分析目标基因表达的可靠性。【方法】选择10种候选内参基因用于进行实时荧光定量PCR（qRT-PCR）, 利用5种软件对柑橘大实蝇在不同虫态下（低龄幼虫、3龄幼虫、1日龄蛹、80日龄蛹、160日龄蛹、雄成虫、雌成虫）以及成虫不同部位（成虫头、胸、腹、整体）中候选内参基因的Ct值进行分析, 明确其表达的稳定性。【结果】在柑橘大实蝇不同虫态和成虫不同部位, 10种候选内参基因的Ct值都处于15~30之间, 各基因Ct值的不同表明各基因的表达量存在差异。 综合分析各种软件对内参基因稳定性的排名, 结合geNorm软件对最佳内参基因数量的分析结果, 推荐在不同虫态下采用UBQ, GAPDH和GST作为内参基因, 在不同成虫部位中采用TUB, GAPDH和GST作为内参基因。【结论】为了获取可信的目标基因表达分析结果, 建议根据不同条件选择使用不同的内参基因组合。本研究结果有利于进一步研究柑橘大实蝇在特定条件下的目标基因表达。     

柑橘大实蝇对不同颜色和糖类的偏好及对糖类的嗅觉反应

为探明影响柑橘大实蝇Bactrocera minax(Enderlein)成虫取食偏好的因素,本文研究了其对不同颜色和糖类物质的选择及其嗅觉反应。结果表明:柑橘大实蝇成虫明显偏好黄色和橙色基质的食物,对绿、白、蓝、黑、红色食物趋性较弱;对不同糖类的选择顺序是:红糖蜂蜜蔗糖和白糖;不同采集地间和不同性别间的柑橘大实蝇对颜色、糖类物质的选择差异不显著。嗅觉行为测试结果,柑橘大实蝇雌雄虫对所测试几种糖的气味均表现明显趋性,其中,雌虫对红糖和蜂蜜气味的嗅觉反应比雄虫更敏感。研究结果可以为柑橘大实蝇成虫食诱剂的研制和诱捕器的设计提供重要参考依据。     

Evolution of hyperflexible joints in sticky prey capture appendages of harvestmen (Arachnida,Opiliones)

The rigid leg segments of arthropods are flexibly connected by joints, which usually consist of two ball-and-bowl hinges, permitting a uniaxial pivoting up to 140°. Here, we report the occurrence of hyperflexible joints (range of movements?=?160–200°) in the pedipalps (second pair of appendages) of some harvestmen (Sabaconidae and Nemastomatidae), representing some of the most flexible leg joints among arthropods. Hyperflexion is achieved by a reduction of hinges and a strong constriction of the joint region. We demonstrate that hyperflexion occurs during prey capture and is used to clamp appendages of the prey, in addition to attachment by glue secreted by specialized setae. By means of high-speed video recordings, we found that in the Sabaconidae the tibiotarsal joint of the pedipalp can flex extremely rapidly (<5 ms), limiting prey escape. This is the fastest reported predatory strike in arachnids and caused both by leverage and a click mechanism. By comparative analysis of different related taxa, we retraced joint evolution and found that hyperflexion has independently evolved in Sabaconidae and Nemastomatidae, with totally different joint kinematics. We hypothesize that (rapid) hyperflexion evolved to enhance the efficiency of the pedipalp as a means of prey capture, because in springtails detachable scales limit the action of the sticky secretion of pedipalpal setae.     

Characterisation of pericentrometric and sticky intercalary heterochromatin in Ornithogalum longibracteatum (Hyacinthaceae)

The hexaploid liliaceous plant Ornithogalum longibracteatum (2n=6x=54) has a heterochromatin-rich bimodal karyotype with large (L) and small (S) chromosomes. The composition and subgenomic distribution of heterochromatin was studied using molecular and cytological methods. The major component of centromeric heterochromatin in all chromosomes is Satl, an abundant satellite DNA with a basic repeat unit of 155 bp and an average A+T content (54%). The major component of the large blocks of intercalary heterochromatin in L chromosomes is Sat2, an abundant satellite DNA with a basic repeat unit of 115 bp and a high A+T content (76%). Additionally, traces of Sat2 can be detected at the centromeric regions of S chromosomes, while minor amounts of Satl are discernible in intercalary heterochromatin of L chromosomes. The chromosomal localisation pattern of Sat2 is consistent with the fluorescent staining pattern obtained with the A+T-specific DNA ligand 4'-6-diamidino-2-phenylindole (DAPI). A+T-rich intercalary heterochromatin is sticky and tends to associate ectopically during mitosis. Sister chromatid exchange clustering was found at the junctions between euchromatin and heterochromatin and at the centromeres. The pattern of mitosis-specific phosphorylation of histone H3 was not uniform along the length of the chromosomes. In all L and S chromosomes, from early prophase to ana-/telophase, there is hyperphosphorylation of histone H3 in the pericentromeric chromatin and a slightly elevated phosphorylated histone H3 level at the intercalary heterochromatin of L chromosomes. Consequently, the overall phosphorylated histone H3 metaphase labelling resembles the distribution of Satl in the karyotype of O. longibracteatum.     

Novel visual-cue-based sticky traps for monitoring of emerald ash borers, Agrilus planipennis (Col., Buprestidae)

We examined various methods of trapping emerald ash borers (EAB), Agrilus planipennis Fairmaire, using solely visual cues based on previous work that has documented the importance of visual cues in EAB mate location. Here, we give the results of two of these methods, coloured sticky cards (yellow or blue), or live ash leaves covered with spray-on adhesive to which dead male EAB visual lures had been pinned. Feral male beetles were captured effectively on the sticky traps made from dead male EAB on ash leaves. These sticky-leaf-traps captured more male EAB when deployed in high-population density areas than low-density areas, but did capture EAB even at lower population densities. More feral males were captured on these traps when they were placed higher in the trees, regardless of the population density of EAB. Very few feral female EAB were captured using the sticky-leaf-traps. This novel method of EAB trapping may allow 'real-time' population detection and monitoring of EAB adults during the active flight period rather than locating larval galleries during the autumn and winter after adult flight and attack. Feral male beetles were also captured using standard yellow- or blue-coloured sticky cards to which male EAB had been affixed with adhesive; however, this type of trap was much less effective overall than using the sticky-leaf-traps. Furthermore, Agrilus cyanescens , a species similar in colour to EAB but smaller in size, showed a strong response to blue-coloured sticky traps to which dead male EAB had been affixed with adhesive, suggesting a general use of visual cues in the mating systems of some of the other Buprestidae as well.     

Directional cloning of native PCR products with preformed sticky ends (Autosticky PCR)

A novel method for the directional cloning of native PCR products was developed. Abasic sites in DNA templates make DNA polymerases stall at the site during synthesis of the complementary strand. Since the 5′ ends of PCR product strands contain built-in amplification primers, abasic sites within the primers result in the formation of 5′ single-stranded overhangs at the ends of the PCR product, enabling its direct ligation to a suitably cleaved cloning vector without any further modification. This “autosticky PCR” (AS-PCR) overcomes the problems caused by end sensitivity of restriction enzymes, or internal restriction sites within the amplified sequences, and enables the generation of essentially any desired 5′ overhang. Received: 11 August 1998 / Accepted: 2 October 1998     

Directional cloning of native PCR products with preformed sticky ends (Autosticky PCR)

A novel method for the directional cloning of native PCR products was developed. Abasic sites in DNA templates make DNA polymerases stall at the site during synthesis of the complementary strand. Since the 5′ ends of PCR product strands contain built-in amplification primers, abasic sites within the primers result in the formation of 5′ single-stranded overhangs at the ends of the PCR product, enabling its direct ligation to a suitably cleaved cloning vector without any further modification. This “autosticky PCR” (AS-PCR) overcomes the problems caused by end sensitivity of restriction enzymes, or internal restriction sites within the amplified sequences, and enables the generation of essentially any desired 5′ overhang.     

A sticky situation: solifugids (Arachnida, Solifugae) use adhesive organs on their pedipalps for prey capture

Solifugids (Arachnida, Solifugae) have unique evertable adhesive organs on the tips of their pedipalps, named ‘suctorial’ or ‘palpal’ organs. Previous studies have shown that these organs enable solifugids to climb smooth glass-like surfaces and have hypothesized that these structures facilitate prey capture. Here, we use high-speed videography to demonstrate that the suctorial organs of Eremochelis bilobatus are its primary means of capturing insect prey. We also present calculations of the adhesive pressure exerted by these suctorial organs during real prey capture events.     

Rapid estimation of numbers of whiteflies (Hemiptera: Aleurodidae) and thrips (Thysanoptera: Thripidae) on sticky traps

The presence or absence of greenhouse whiteflies, Trialeurodes vaporariorum Westwood, and thrips, primarily western flower thrips, Frankliniella occidentalis (Pergande), in cells of a grid laid over 7.6 cm by 12.7 cm sticky traps was used to estimate the population density of these pests on the trap. The method accurately predicted trap population densities of between 15 and 192 individuals per side for thrips on blue and yellow traps and between 15 and 168 whiteflies per side on yellow traps. The distribution of both whiteflies and thrips tended to be clustered on the sides and upper edge of the traps. The method is useful in giving a far more rapid estimate than counting individuals, particularly at high population densities.     

Relationship between Aphis gossypii (Homoptera: Aphididae) and sticky lint in cotton

The study was conducted in the northern Texas Rolling Plains in 1999 to define the relationship between number of cotton aphids, Aphis gossypii Glover, and resulting contamination of cotton lint by honeydew. Whole-plot treatments were three furrow irrigation management treatments: cotton grown without supplemental irrigation (dryland), irrigated cotton with last irrigation in mid August, and irrigated cotton with last irrigation in late August. Subplots within each irrigation treatment included an untreated check, a plot treated with lambda-cyhalothrin to stimulate aphid population increase, a plot treated with lambda-cyhalothrin followed by pymetrozine after aphids began to increase, and a plot treated with lambda-cyhalothrin followed by thiamethoxam after aphids began to increase. Cotton aphids were counted on leaves picked from the top and bottom half of the plant. Cotton lint was analyzed for contamination by glucose, fructose, sucrose, and melezitose secreted by cotton aphids, and percentage leaf moisture and nitrogen and leaf sucrose concentrations were determined. The manual sticky cotton thermodetector was used to determine degree of lint stickinesss. There was a significant relationship between thermodetector counts and melezitose contamination on lint, and a melezitose concentration of 90.9 microg/g of lint was associated with a thermodetector count of 10, the threshold for sticky lint problems in textile mills. An equation was developed to estimate melezitose concentration on lint as a function of average numbers of aphids per leaf and the interaction between percentage leaf moisture and nitrogen. The number of aphids per leaf associated with a melezitose concentration of 90.9 microg/g of lint ranged from 11.1 to 50.1, depending on percentage leaf moisture and nitrogen. The threshold for sticky lint problems occurred when aphid numbers ranged between 11.1 and 50.1 per leaf after bolls open.     

Plasmodium's sticky fingers

The life cycle of the malaria parasite (Plasmodium) is remarkably complex. Malaria parasites must engage in highly specific and varied interactions with cell types of both the mammalian host and the mosquito vector. In this issue of Cell, report detailed molecular insights into an intimate interaction between a malaria parasite protein and its host cell receptor that enables the parasite to invade erythrocytes.