作为松材线虫病(Bursaphelenchus xylophilus)的最重要传播媒介,松褐天牛已成为控制松材线虫病的重点。明确松褐天牛各虫态在不同地区寄主树干上的分布,对因地适宜地释放天敌昆虫有着重要意义。为此,本研究通过解剖受害马尾松,结合林间调查,系统地研究了松褐天牛产卵刻槽、幼虫和蛹在马尾松树干上的分布规律。结果表明:松褐天牛产卵刻槽主要分布在树干的2.5 6.5 m范围内,刻槽数量与树干高度和胸径显著相关;松褐天牛幼虫数量与树干胸径关系不显著;多数蛹室位于侵入孔正上方,少数蛹室位于侵入孔下方,两种蛹室数量差异显著;两种蛹室与侵入孔中心的平均距离分别为3.93 cm和4.39 cm,两者之间差异不显著;并建立了松褐天牛幼虫在马尾松树干上的垂直分布模式图。本研究表明了松褐天牛种群密度与寄主树木大小的关系,为释放天敌进行生物防治提供了基础。

The Asian long-horned beetle, Anoplophora glabripennis is a polyphagous xylophage native to Asia. This beetle is the most serious pest in the Three-north Areas of China. Dastarcus helophoroides plays an important role in biological control of the Asian long-horned beetle. In order to determine the probability of introducing this natural enemy to control A. glabripennis in the northwest of China, the overwintering survival of D. helophoroides in north China is a most important issue which should be understood. The overwintering place and survival of D. helophoroides were investigated respectively. The supercooling points of overwintering and laboratory strains of this parasitic beetle were assayed. The results indicated that most of this parasitic beetle chose the long-horned beetle pupa cell and the gallery as their overwintering place. A small proportion of them completed their overwintering process beneath the bark. Over 50% proportion of this beetle can complete the overwintering process successfully. Furthermore, the cold tolerance of overwintering strain was much stronger than that of the laboratory strain. These findings suggested that D. helophoroides can successfully accomplish the overwintering process in northwest of China. This might provide a support for introducing D. helophoroides to control the Asian long-horned beetle in these places.

目的 松材线虫病是我国对森林危害和威胁最严重的病害，控制其传播媒介昆虫松褐天牛是防治松材线虫病的主要手段。作者发现的松褐天牛深沟茧蜂（Iphiaulax monochamusi Yang）是寄生松褐天牛中老龄幼虫的重要天敌。为明确松褐天牛深沟茧蜂的寄生率与寄主树木、寄主和环境因子的关系，开展了本研究。 方法 通过解剖46株松褐天牛危害致死的马尾松，调查了松褐天牛深沟茧蜂寄生率与马尾松、松褐天牛和环境因子之间的关系。 结果 调查研究表明：寄主树木的高度、胸径和树龄对松褐天牛深沟茧蜂寄生率没有显著影响，松褐天牛的数量对松褐天牛深沟茧蜂寄生率亦没有显著影响，而松褐天牛幼虫龄期和松褐天牛幼虫在树干上的位置显著影响松褐天牛深沟茧蜂寄生率。松褐天牛深沟茧蜂寄生率与松褐天牛龄期呈显著正相关，其偏好寄生3~5龄幼虫；就天牛在其危害寄主树木上的位置而言，松褐天牛深沟茧蜂偏好寄生马尾松主干上部和在韧皮部危害的松褐天牛幼虫，其对位于马尾松树干上部的寄主幼虫寄生率最高，达27.38%，对在韧皮部生活、危害的寄主幼虫寄生率为20.18%，显著高于位于木质部生活的寄主幼虫寄生率（5.46%）。逐步回归分析表明：影响松褐天牛深沟茧蜂寄生率的关键环境因子是寄主树木的坡位和其它天敌寄生率，其中，坡位与松褐天牛深沟茧蜂呈显著正相关，其它天敌寄生率与松褐天牛深沟茧蜂寄生率呈显著负相关。 结论 以上研究初步明确了松褐天牛深沟茧蜂的寄生率与寄主树木、寄主害虫和天敌之间的关系，为今后利用该重要天敌控制松褐天牛打下了基础。

根据昆虫病原真菌毒素的分子量和结构分为低分子量毒素和高分子蛋白毒素两大类,根据结构将低分子量毒素分为环缩肽类、色素类、有机酸类和其它类,根据功能将大分子蛋白毒素分为酶类毒素和非酶类蛋白毒素。对白僵菌素、破坏素等多种昆虫病原真菌毒素的结构和性质进行了阐述。从昆虫病原真菌产毒素的适宜培养条件到毒素的分离纯化方法、毒素毒力的生物测定和毒素的致病机理等方面的研究进展情况进行了评述。

天牛幼虫排出的虫粪在指示天敌寻找寄主的过程中起着重要的作用。通过在光肩星天牛幼虫发生期定期收集幼虫虫粪的方法,首次研究了林间天牛幼虫排粪量的变化规律。结果显示,光肩星天牛成虫羽化前,排粪总量呈现由上升到下降的过程,单个排粪孔的日平均排粪量为(0.030 2±0.002 1)g,单排粪孔的日最大排粪量可以达到0.319 4 g。同时研究了幼虫排粪量与寄主树的胸径、树皮厚度、树皮含水量和排粪孔大小的关系,结果表明,在调查期内,无论是各个排粪孔的排粪总量还是日均最大排粪量,均与排粪孔的大小有直接关系,而与其他几个因子无关。通过在树干上缠绑胶带形成的微栖境,采集到了光肩星天牛的天敌花绒寄甲成虫,表明花绒寄甲的发生与寄主天牛的发生紧密相关。

Rhizophagus grandis (Coleoptera: Rhizophagidae) is an important predator of Dendroctonus valens which is an invasive alien pest attacking pine trees in China. It was first introduced into China in 2000 and mass rearing techniques had been developed by the authors since then. This paper dealed with the study on the developmental threshold temperature and the effective accumulated temperature of R. grandis. The result showed that the developmental threshold temperatures of egg, larva and pupae were 3.59±2.92 ℃, 1.96±0.73 ℃ and 9.27±1.19 ℃ respectively, and the effective accumulated temperatures were 98.32±16.26 degree-day, 296.94±12.45 degree-day and 449.67±53.19 degree-day respectively. Therefore, the total effective accumulated temperature from egg to pupa was 844.93 degree-day.

研究了13个与栗山天牛危害程度有关的林分因子,并对这些林分因子与栗山天牛危害林地有虫株率进行逐步回归分析,从中筛选出林地坡位、栎树胸径和主林层郁闭度3个关键因子。结果表明:栗山天牛危害林地有虫株率(y)与坡位(x1)和胸径(x6)呈显著正相关关系,与主林层郁闭度(x4)呈显著负相关关系,依此建立多元回归模型:y=0.071 2+0.691 8x1-0.507 4x4+0.561 3x6,经检验,平均差异程度为0.174 2。因此,可用该模型对栗山天牛危害程度进行风险评估。

研究测定了松褐天牛肿腿蜂对松褐天牛1 3龄幼虫的控制作用, 采用林间和室内罩网相结合的方法研究了2组松褐天牛肿腿蜂对松褐天牛幼虫的寄生情况。结果显示:在室内试验条件下,松褐天牛肿腿蜂产卵之前的刺蛰、补充营养取食能直接造成松褐天牛1 3龄幼虫死亡,对1、2及3龄幼虫的平均致死率分别为95.66%、85.91%、57.88%,并可产卵寄生2、3龄幼虫;林间释放2组松褐天牛肿腿蜂后,在刺蛰和补充营养取食后能有效寄生寄主的肿腿蜂雌蜂数量比例变化较大,有效肿腿蜂率最高为14.9%,最低为2.3%。松褐天牛肿腿蜂寄生行为不受寄主聚集程度的影响,但刚羽化出茧肿腿蜂雌蜂的寄生效率比经饲喂后的雌蜂高近5倍。从肿腿蜂单一个体来看,每头雌蜂补充营养取食和产卵寄生致死的松褐天牛幼虫数为2.1 7.7 头。松褐天牛肿腿蜂雌蜂的补充营养习性及刺蛰、取食致死寄主行为在防治中有很重要的作用,表明该种肿腿蜂是防治松褐天牛的重要天敌,在生物防治松褐天牛幼龄幼虫上具有良好的应用前景。

In recent years, Agrilus mali Matsumura has outbroken in the Xinjiang wild fruit forest, and become the primary threat to Malus sieversii. In early study, the larvae of Agrilus mali were divided into six instars. However, the particular reason and method were not mentioned, and the larvae of Genus Agrilus were usually divided into four or five instars. For better pest forecasting and control strategies, the determination of larval instars was studied again. A.mali larvae were sampled periodically in forest, and the eggs were collected to hatch the first instar larvae. Three characteristics (i. e. peristoma width, urogomphus length and body length) were measured by binocular microscope with an eyepiece micrometer. According to the Dyar's law, the data were managed with frequency analysis, and examined by one-way ANOVA method, Crosby ratio and checked with larvae which were molting when sampling. The results showed that, the A. mali larva has five instars, and all three determination characteristics are effective except body length.

本文对天牛卵期寄生性天敌的研究进展进行了综述。已有文献表明该领域的研究多集中在天敌资源调查、天敌分类与系统发育、天敌生物学特性、行为学特性、生殖与遗传多样性、化学生态学等方面，大部分属于基础性研究；但相对其他类群害虫的卵寄生蜂研究较少；仅见对极少数几种天牛卵寄生蜂的行为学、化学生态学机制有过较深入的探讨。天牛卵寄生蜂应用于生物防治实践的研究更少，这可能与天牛卵寄生蜂虫源获取困难、饲养技术研究薄弱有关，天牛卵寄生蜂的规模化繁育技术也制约了其生物防治利用。本综述对全面了解天牛卵期寄生性天敌研究进展提供了便捷，为今后加强和深入对天牛卵寄生蜂的研究利用提供了参考。