氯虫苯甲酰胺对荔枝蒂蛀虫不同虫态的室内毒力测定

荔枝蒂蛀虫Conopomorpha sinensis Bradley是为害荔枝和龙眼的重要害虫，其为害的隐蔽性增加了防治难度。为了探索安全、有效的药剂防治手段和明确氯虫苯甲酰胺的适合施药时期，本研究在室内条件下，以防控荔枝蒂蛀虫常用药剂高效氯氟氰菊酯为对照药，采用喷雾法和药膜法，分别测定了100、10、1、0.1和0.01 mg/L的 5个浓度梯度下，氯虫苯甲酰胺对荔枝蒂蛀虫卵、初孵幼虫的毒杀作用以及对成虫的触杀作用。研究结果表明，氯虫苯甲酰胺的5个浓度梯度对产后24 h、48 h和72 h蒂蛀虫卵孵化抑制率均显著高于高效氯氟氰菊酯；氯虫苯甲酰胺对蒂蛀虫初孵幼虫的毒力是高效氯氟氰菊酯的10倍，对荔枝蒂蛀虫初孵幼虫的LC50分别为3.32 mg/L和38.78 mg/L。而在100 mg/L浓度下氯虫苯甲酰胺和高效氯氟氰菊酯对成虫触杀的校正死亡百分率最高分别为34.36%和77.35%。综上所述，氯虫苯甲酰胺对荔枝蒂蛀虫具有较强的杀卵活性和杀初孵幼虫活性，在荔枝生产上具有潜在的应用价值；鉴于其对成虫的触杀作用不强，故建议在荔枝蒂蛀虫的产卵高峰期和初孵幼虫期使用，以期将荔枝蒂蛀虫于发生为害之前进行有效控制。     

荔枝蒂蛀虫室内饲养技术的研究

室内试验结果表明,利用荔枝种仁作为食物成功饲养荔枝蒂蛀虫至完成一世代.荔枝蒂蛀虫在荔枝、龙眼鲜果表皮产卵量较高,10 d产卵数分别为88.33和179.33粒/处理.蒂蛀虫卵散产在特制收卵卡的凹陷处且呈规则排列.选荔枝种仁作为其食物,并注入清水保持种仁的湿度,荔枝蒂蛀虫在角度90～150 °折纸内化蛹,化蛹率和羽化率分别为33.67%和94.06%.     

荔枝蒂蛀虫幼虫龄数及各发育阶段在不同温度下的发育历期

【目的】荔枝蒂蛀虫 Conopomorpha sinensis Bradley是荔枝龙眼上的主要害虫,以幼虫蛀果为害。本研究旨在明确荔枝蒂蛀虫幼虫龄数及不同温度下各虫态和各龄幼虫的发育历期,为该虫发生规律、预测预报和防控技术研究提供基础生物学数据。【方法】定期收集处于不同发育时期的荔枝蒂蛀虫幼虫,测量幼虫头壳宽度,对其进行频次分析,Crosby指数验证和曲线回归分析,以确定幼虫龄数。通过室内群体饲养的方法,测定了17~38℃区间8个温度梯度下荔枝蒂蛀虫各虫态和各龄幼虫的发育历期,并采用线性日度模型对其发育速率与温度的关系进行回归分析。【结果】根据荔枝蒂蛀虫幼虫头壳宽度频次分布图,其头壳宽度的频次分布可明显分为5个区域,说明其幼虫分5个龄期,符合Dyar定律。1-5龄幼虫的头壳宽度分别为：0.092~0.120, 0.140~0.206, 0.217~0.319, 0.356~0.523和0.582~0.728 mm。温度对荔枝蒂蛀虫卵、各龄幼虫和蛹的发育历期有明显影响,其发育历期均随温度的升高而缩短,其发育速率均与温度呈显著正相关,并符合线性回归模型。在20~32℃,荔枝蒂蛀虫可完成世代发育;在17℃时,该虫只能发育至3龄幼虫;在35℃时,蛹多不能羽化;在38℃时,卵多不能孵化。在20~32℃,其世代历期为41.16~19.34 d,蛹期为12.74~5.38 d,而产卵前期为4.75~4.22 d,温度对产卵前期无明显影响。在20~35℃,荔枝蒂蛀虫幼虫可正常发育,其1龄幼虫龄期为4.50~1.17 d,2龄幼虫期为2.09~1.40 d,3龄幼虫期为2.84~1.00 d,4龄幼虫期为3.41~1.18 d,5龄幼虫期为3.00~1.37 d,预蛹期为2.41~0.69 d。在17~35℃,荔枝蒂蛀虫卵可正常孵化,其卵期为7.73~2.09 d。【结论】荔枝蒂蛀虫幼虫分5个龄期,不同于前人所报道的4个龄期。在20~32℃温度范围内,卵、各龄幼虫和蛹的发育历期均随温度升高而缩短。本研究结果有助于荔枝蒂蛀虫预测预报方案的制定和实施。     

荔枝蝽田间种群消长动态及空间分布型研究

对海南省儋州地区荔枝园中荔枝蝽Tessaratoma papillosa(Drury)种群动态及空间分布进行了系统调查与分析。结果表明,在2005—2006与2008—2009年期间,荔枝蝽的产卵高峰期分别为4月与2月,若虫高峰期为3月,成虫高峰期分别为4月及7月;分析表明荔枝蝽各虫态在荔枝园中均为聚集分布,且成虫个体间相互排斥。     

荔枝蒂蛀虫成虫对LED光的趋性及其繁殖响应特征

为明确荔枝蒂蛀虫Conopomorpha sinensis成虫对不同LED光的趋性行为反应,初步筛选出该虫趋光性不同的光色并进一步研究其对成虫繁殖生物学特性的影响,以期为今后研发特异性强且绿色高效的荔枝蒂蛀虫灯光防控技术提供理论依据.本文采用对比实验法,测试了荔枝蒂蛀虫雌蛾对9种供试光源的趋性行为反应,并进一步研究夜间LED光照射对荔枝蒂蛀虫成虫交配率、繁殖力及寿命的影响.结果显示,荔枝蒂蛀虫雌成虫对不同LED光的趋光反应率由高到低为:蓝(445～450 nm)>紫(400～405 nm)>红(655～665 nm)>蓝绿(475～480 nm)>橙(600～605 nm)>绿(515～520 nm)>黄(570～575 nm)>白(400～700 nm)>黑暗>紫外(365 nm),试虫对紫外光表现出明显的避光性,对7种单色光表现为不同程度的趋光性,其中对黄光和白光的趋光率在50％以下.在繁殖生物学方面,夜间50 lx的LED黄光和白光持续照射能使荔枝蒂蛀虫成虫的交配率由93.75％降低至50％以下,且产卵前期延长,雌蛾产卵量显著降低.此外,夜间不同LED光源照射能抑制已交配荔枝蒂蛀虫雌蛾产卵活动,白光照射组的单雌日均产卵量降低程度最大,为50.71％,黄光次之(48.96％),蓝光最小,为38.06％.综上所述,荔枝蒂蛀虫雌蛾对LED白光和黄光的趋光性较弱,夜间适当的LED白光(400～700 nm)和黄光(570～575 nm)持续照射可有效降低成虫交配率和繁殖力,该结果对促进LED白光干扰防控荔枝蒂蛀虫技术的优化升级具有一定指导意义.     

豚草条纹萤叶甲各虫态的空间分布型

豚草条纹萤叶甲Ophraella communa LeSage是恶性入侵豚草(Ambrosia artemisiifolia L.)的天敌,用频次分布拟合和多种聚集指数测度等方法对该叶甲的成虫、幼虫和蛹、卵的空间分布型进行研究。结果表明,豚草条纹萤叶甲卵、幼虫+蛹、成虫的空间分布符合负二项分布,种群个体的空间分布为聚集分布。用几种衡量聚集度的指标,对上述各虫态分布的聚集程度进行测定;然后计算出各虫态田间最适理论抽样数。     

荔枝蒂蛀虫研究进展

荔枝蒂蛀虫Conopomorpha sinensis是中国岭南地区、东南亚、印度和尼泊尔一带广泛分布的重要果树害虫。该虫以幼虫钻蛀取食荔枝和龙眼的果实、嫩梢、花穗,隐蔽性强,防治困难,加上防治措施不当,化学农药的滥用,使得该虫迅速成为这两种优质名果的最主要害虫。本文整理近30年荔枝蒂蛀虫的研究报道,从分类学,生物学特性,触角感器及嗅觉机制,人工饲养技术,以及预测预报和防治方法等方面详细介绍了荔枝蒂蛀虫的研究进展,提出在荔枝蒂蛀虫的研究中存在的一些争议问题,并对今后的研究方向进行了展望。     

荔枝蒂蛀虫绿色防控研究进展

中国是荔枝(Litchi chinensis)的原产地,种植面积和产量规模均居世界第一位,以“岭南果王”著称的中国荔枝在国际鲜果市场享有极高的声誉。荔枝蒂蛀虫(Conopomorpha sinensis)在我国广泛分布于热带南亚热带地区,是荔枝的主要害虫,其幼虫蛀食荔枝果核、果蒂,会影响果实生长发育及商品果率,造成严重的经济损失。荔枝蒂蛀虫的行为隐蔽,世代重叠,难以控制。目前生产上对该虫的控制主要依靠化学防治,但长期使用化学农药容易产生污染环境、药物残留、食品安全以及虫抗药性的问题。本文结合国内外研究进展,着重从荔枝蒂蛀虫生活习性及危害发生规律、预测预报、物理防治、生物防治及生物源农药应用等方面进行综述,并对荔枝蒂蛀虫绿色防控研究方向及以农业防治为基础的综合防治方法进行展望。     

寄主植物对荔枝蒂蛀虫产卵的引诱作用

试验观察荔枝蒂蛀虫Conopomorpha sinensisBradley对寄主植物品种、器官及器官部位的产卵选择性规律。结果表明,与老梢相比,荔枝蒂蛀虫明显倾向于选择嫩梢产卵;4个荔枝品种果枝中以妃子笑上落卵数最多,在淮枝、糯米糍荔枝果实上较少,桂味荔枝上最少;不同的荔枝品种果实气味引诱雌虫产卵的能力不同,其中妃子笑引诱力最强,淮枝、糯米糍引诱力较低,桂味最低;在同一荔枝果实不同部位的落卵量,以果皮上、下两部分较大,全果明显低于果皮上部,而荔枝肉和荔枝核上没有落卵。     

印楝素乳油对荔枝蒂蛀虫种群的控制作用

利用生命表的方法和干扰作用控制指数评价了印楝素乳油对荔枝蒂蛀虫Conopomorpha sinensisBradley种群的控制作用,结果表明:0.3%印楝素乳油对荔枝蒂蛀虫成虫显著的产卵忌避作用是其对该种群控制的主要机理。在室内,0.3%印楝素乳油在6 mL/L和3 mL/L的浓度处理下,对荔枝蒂蛀虫成虫产卵的忌避率分别为89.3%和86.3%。田间的试验结果表明,在印楝素乳油浓度为6 mL/L和和3 mL/L的处理区中,荔枝蒂蛀虫的种群趋势指数分别为1.23和1.45,显著低于对照区的种群趋势指数11.60,干扰作用控制指数分别为0.106和0.112。这2个浓度的印楝素乳油对荔枝蒂蛀虫种群的控制效果分别可达89.4%和87.5%。     

On a property of the exponential distribution

If t is an independent exponentially distributed random variable, the distribution p = [t - x] is a modified geometric distribution, similar to the result of HAWKINS and KOTZ (1976), x is uniform.     

Reconstructing the Pleistocene geography of the Aphelocoma jays (Corvidae)

Understanding historical distributions of species and evolving lineages has been a topic of considerable interest, yet methods used to date have not provided detailed, quantitative distributional hypotheses. Here, we present a technique based on models of species’ ecological niches and Pleistocene climate reconstructions that provides such hypotheses, providing the example of reconstructions for the Aphelocoma jays. We demonstrate in general a greater degree than expected of stability in jay species’ distributional areas back through at least the most recent glaciation event, and that existing patterns of genetic differentiation may date to before the Late Pleistocene glaciations. More generally, the method offers the potential for reconstructing historical distributions of species or lineages, and providing a detailed geographic framework for addressing many biogeographic and systematic questions.     

Modelling potential biotope composition on a regional scale revealed that climate variables are stronger drivers than soil variables

Aim

Environmental conditions define the suitability of an area for biotopes, and any area can be suitable for several biotopes. However, most previous studies modelled the distribution of single biotopes ignoring the potential co-occurrence of biotopes in one area, which limits the usefulness of such models for conservation and restoration planning. In this study, we described the potential biotope composition of an area in response to environmental conditions.

Location

Bavaria, Federal State of Germany.

Methods

Based on the Bavarian biotope mapping data, we modelled the distribution of 29 terrestrial biotopes based on six climate variables and six chemical and four physical soil properties using the species distribution modelling algorithm Maxent.

Results

For most biotopes, we found that climate variables were more important than soil variables for the biotope distribution and that the area of the predicted biotope distribution was larger than the observed distribution. The potential biotope composition illustrated that while 8% of the area in Bavaria was not sufficiently suitable for any analysed biotope, 92% of the modelled area in Bavaria was suitable for at least one biotope, 84% for two and 77% for at least three biotopes. The difference in suitability between the most suitable biotopes in composition was minor. Further, over one-quarter of the modelled area was suitable for 6–8 different biotopes.

Main Conclusions

Our study showed that considering a composition of potentially suitable biotopes in a raster cell, instead of only the most suitable biotope, provides valuable information to identify conservation priorities and restoration opportunities.     

Evaluation of the spatial distribution of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) in South Korea combining climate and host plant distribution

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), a global forest pest, has a potential to damage forests in South Korea, requiring an effective tool for evaluating its potential distribution. This study aimed to evaluate the spatial distribution of A. glabripennis in South Korea by simultaneously considering climate and host plants. Climatic suitability was firstly evaluated using a CLIMEX model; then, it was combined with the areal distribution of host plants using a simple mathematical formulation. We finally projected the spatial distribution of A. glabripennis onto the map of administrative districts to identify hazardous areas to watch. As a result, the developed model predicted that over 40% of areas in South Korea could be exposed to A. glabripennis damage, and most of them were located in mountainous areas with abundant host plants. In addition, climatic suitability was higher in coastal areas, which was different than a previous record of A. glabripennis occurrence, while the prediction by a comprehensive model was consistent with the record. In conclusion, the model including both climate and host plant occurrence was more reliable than the model which only included climate, and could provide useful data for determining areas for monitoring and control.     

On the Discrete POISSON-Inverse GAUSSian Distribution

The discrete POISSON-inverse GAUssian distribution is obtained by compounding the POISSON distribution with the inverse-GAUssian distribution. The maximum likelihood of the parameter is discussed. Comparison with the POISSON, negative binomial, POISSON-LINDLEY and the generalized WARING distribution when fitting a distribution to accident statistics data is given.