松墨天牛对寄主树木的产卵选择

在室内采用选择行为方法,研究了松墨天牛Monochamus alternatus对几种松属植物的产卵选择行为。结果表明,松墨天牛对黑松Pinus thunbergii的选择性最强,对马尾松P.massoniana的选择性最弱,二者间差异显著,它们与火炬松P. taeda和湿地松P. elliottii间无明显差异。在黑松和马尾松的被松材线虫危害木与健康木之间,松墨天牛明显选择被害木产卵;具产卵痕枝段和虫粪处理过的枝段,对松墨天牛的产卵有显著抑制作用,松墨天牛明显地选择对照枝段产卵。     

林冠截持降雨模型的初步研究

通过对林冠截持过程的研究,将单场降雨划分成很多个小的时段,顺序计算各小时段内降雨在林冠内的分配,建立了一个林冠降雨截持模型.模型考虑了冠层和树干干燥度对冠层雨期蒸发的影响,并在计算雨期蒸发时引入冠层叶面积指数、单位林地面积上树干表面积.运用模型对华北落叶松林的降雨截持进行模拟,结果表明,模拟穿透雨与实测穿透雨基本吻合,误差在±1 mm范围内,但在小降雨(＜6 mm)时模拟值偏低;树干茎流量模拟值偏低,茎流模拟相对误差随着降雨量增大而减小.同时模拟了穿透降雨的过程,结果与林内自动气象站实测穿透降雨的过程基本吻合,模拟效果较好.     

松墨天牛和光肩星天牛染色体核型

以松墨天牛Monochamus alternatus Hope和光肩星天牛Anoplophora glabripennis Motschulsky为研究对象,以各种天牛的最适条件和最佳材料进行染色体的制备和观察。试验结果如下:松墨天牛的最佳试验材料为7日龄蛹的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体5对,中型染色体4对,性染色体在其大小排列中位于最末位,为中型染色体,染色体组式为5L+4M+Xyp;光肩星天牛的最佳试验材料为初羽化成虫的精巢或卵巢,染色体数目2n=20,性别决定机制为Xyp,有大型染色体6对,中型染色体3对,性染色体在其大小排列中位于最末位,但也为中型染色体,染色体组式:6L+3M+Xyp。     

松墨天牛成虫交配与产卵行为的观察

观察了养虫笼中松墨天牛Monochamus alternatusHope的交配和产卵行为。描述了雌、雄虫在交配过程中的多种行为,雌、雄虫间的交配时间可持续23~540 min,平均约200 min;有重复交配现象,重复交配次数可达2~18次;每次交配持续时间为2~100 s。雌虫背负雄虫,边取食边产卵;也可脱离雄虫单独产卵。雌虫在寄主枝条上咬槽产卵,通常日产卵1~2粒,最多3粒。产卵期的长短和产卵量的多少取决于雌虫个体寿命的长短。     

六盘山华北落叶松林和红桦林枯落物持水特征及其截持降雨过程

在六盘山南坡野外调查了华北落叶松(Larix principis-rupprechtii)和红桦(Betula albo-sinensis)两个林分的枯落物数量特征,其厚度分别是3.6cm和4.0cm,储量为16.83 t/hm2和9.04 t/hm2.浸泡测定了单位重量(1.0kg/m2)枯落物的持水能力,华北落叶松林和红桦林的最大持水深分别是1.8 mm和2.7 mm.在六盘山地区自然雨强范围内(<30 mm/h),利用模拟降雨研究了枯落物的截持降雨过程,表明枯落物持水能力随雨强增大而提高;在雨强为30 mm/h时,华北落叶松林和红桦林枯落物(1.0kg/m2)的最大截持雨量为1.5mm和2.6mm,分别是浸泡测定持水能力的83.3%和96.2%,两种实验吸持水分的过程基本一致.分析表明,枯落物截持过程的吸水速率受其本身含水量大小的影响,同时构建了具有较好截持机制的枯落物截持降雨过程模型,并基于枯落物浸泡实验和模拟降雨截持实验的数据拟合了模型参数.     

松墨天牛的全球潜在分布区分析

松墨天牛MonochamusalternatusHope分布在亚洲东部,是松材线虫Bursaphelenchusxylophilus(SteinerandBuhrer)在亚洲最有效的昆虫媒介,同时也是重要的蛀干害虫。利用CLIMEX模型分析松墨天牛分布区的气候限制因子,并在全球范围预测它的潜在分布区。模型分析结果表明,温度和降水是松墨天牛分布区的主要气候限制因子。温度在30°N以北地区和30°S以南地区主要表现为冷胁迫,在非洲中部、南亚和澳大利亚北部表现为热胁迫。有效积温不足可能是限制松墨天牛向北扩散的主要原因。降水在中国西北地区、非洲中北部、澳大利亚中部和西部与美国西部主要表现为干胁迫。降水量对分布区范围影响不大。预测结果表明,松墨天牛的全球潜在分布区远远大于实际分布范围。松墨天牛在东半球的潜在分布区包括亚洲东部和南部地区、地中海沿岸、非洲的中部和南部以及澳大利亚的东部和南部,在亚洲热带的潜在分布区1年3代,地中海地区1年1代,非洲1年2～3代,在澳大利亚主要1年1代。松墨天牛在西半球的潜在分布区主要集中在美国南部和东部沿海地区,中美洲以及南美洲的广大地区,美国主要1年1代,中美洲1年2～3代,南美洲主要1年2代。     

松墨天牛成虫头部感受器超微结构的观察

扫描电镜观察表明 ,松墨天牛MonochamusalternatusHope成虫头部存在 1 1种感受器。触角有 8种 ,下颚须和下唇须有 6种。栓锥感受器Ⅰ型、毛形感受器Ⅰ型及刺形感受器为触角、下颚须和下唇须共有。触角特有栓锥感受器Ⅱ型、毛形感受器Ⅱ型、锥形感受器以及柱形感受器Ⅰ型和Ⅱ型。下颚须及下唇须特有钟形感受器、坛形感受器和板形感受器。松墨天牛成虫触角感受器在种类、数量和分布上存在性别差异 ,雌雄虫的下颚须和下唇须感受器数量有所不同。     

Effects of larval food shortage on diapause induction and adult traits in Taiwanese Monochamus alternatus alternatus

To confirm the facultative diapause of Monochamus alternatus alternatus Hope (Coleoptera: Cerambycidae) and to determine the relationships between available larval food resources, diapause, and adult traits, newly hatched larvae were inoculated singly on 98 Pinus densiflora Siebold & Zuccarini (Pinaceae) bolts and reared at 25 °C, 100% r.h., and L16:D8. Fifty adults emerged from them, between 70 and 126 days after larval inoculation. The remaining 48 bolts that did not produce adults were divided into two groups. One group was transferred to 10 °C, 100% r.h., and L8:D16, and returned 140–154 days later to the original conditions, resulting in adult emergence. The other group was maintained under the original conditions for a mean of 358 days. These bolts did not produce adults. Dissection revealed that development was arrested at final instar in pine bolts. The larvae developed into adults after being exposed to 10 °C, 100% r.h., and L8:D16 for 146 days. Consequently, this species has facultative diapause. Diapause incidence was estimated to be 0.42. Non‐linear model and one‐way ANOVA showed a positive correlation between adult body size and available food resources under conditions of food shortage, and no effects of diapause or available food resources on the ovariole number, respectively. When larvae were inoculated on 28 pine branch sections, the results were similar to those obtained from pine bolts and led to estimation of a low diapause incidence of 0.045. The combined data showed the inhibitory effect of food shortage on diapause induction. Diapause of M. a. alternatus, especially reduced diapause induction in response to environmental deterioration (food shortage), is discussed in relation to risk‐spreading.     

Transmission of Bursaphelenchus xylophilus between Monochamus alternatus and Monochamus saltuarius through interspecific mating behaviour

Cerambycid adults of the genus Monochamus transmit the pine wood nematode (Bursaphelenchus xylophilus [Steiner et Buhrer] Nickle), the causative agent of pine wilt disease. To confirm the transmission of B. xylophilus between vector species, nematode‐infected Monochamus alternatus Hope and nematode‐free Monochamus saltuarius (Gebler) adults were paired and their behaviour was observed for 107–220 min. In three pairs that exhibited mounting without copulation, nematode transmission occurred, whereas it was not found in another pair without mountings. The effect of nematode transmission between different vector species on the invasion biology of B. xylophilus is discussed.     

松褐天牛天敌微生物的研究进展

系统总结了国内外在松褐天牛MonochamusalternatusHope天敌微生物方面的研究进展。概述了松褐天牛天敌微生物的种类组成、致病力、应用技术、控制作用和应用前景 ,并简要分析了松褐天牛的危害性和防治现状。天敌微生物特别是病原真菌在松褐天牛的综合治理中有着广阔的应用前景。