天牛幼虫的外部形态及亚科检索图

<正> 天牛科是鞘翅目昆虫中的一个大科,全世界已知4万余种,国内记录已超过2600种。该科种类是农、林业重要害虫。松墨天牛(松天牛)Monochamus alternatus Hope因从国外传带松材线虫Bursaphelenchus xylophilus引起松树萎蔫病,致使南京中山陵等地的松林被毁。我国植检部门已将该种列入对外植物检疫     

星天牛幼虫龄期的划分

本文测量了人工饲养的星天牛Anoplophora chinensis(Forster)幼虫的9个形态结构数据,运用频次分布、均差分析和回归分析对测量数据进行统计分析,结果表明,星天牛幼虫可分5龄,其额宽是最佳的分龄结构,其次是上颚长和上颚宽。     

中国两种狭胸天牛类幼虫的描述（鞘翅目：天牛总科）

天牛类的幼虫特征,已成为天牛总科探讨演化和分类系统的重要手段,狭胸天牛类由于长期以来未找到幼虫,其地位不能确定,影响到整个天牛科和天牛总科的演化和分类系统的研究存在一个缺口。近年在中国广西和西藏发现了松狭胸天牛ＰｈｉｌｕｓａｎｔｅｎｎａｔｕｓＧｙｌｌｅｎｈａｌ和细点音天牛ＨｅｔｅｒｏｐｈｉｌｕｓｐｕｎｃｔｕｌａｔｕｓＣｈｉａｎｇｅｔＣｈｅｎ的幼虫,前者王缉健（１９８９）和尹新明（１９９４）曾有简短报道。本文对这两种幼虫的形态作了详细描述,以供与近缘类群作比较研究。     

锦天牛属阳茎内囊结构

采用显微解剖和冰冻组织切片方法研究锦天牛属Acalolepta三种天牛阳茎内囊的结构,发现内囊骨化结构物,尤其端部骨化结构物,及其控制内囊伸缩的加厚侧带和有聚集精子作用的射精管壶腹结构,在探讨天牛科分类和系统发育上均具有重要意义。     

栗山天牛幼虫龄数和龄期的测定

栗山天牛Massicus raddei (Blessig)是危害我国东北柞树天然林的重要蛀干害虫, 长期营隐蔽性生活, 3年发生1代, 防治困难。幼虫的龄数和龄期测定是害虫预测预报以及制订其科学治理策略的重要依据。本研究于2008-2011年通过林间定期解剖受害树进行取样, 在辽宁省宽甸县采集不同发育阶段的栗山天牛幼虫, 分别测量幼虫上颚长、 主单眼间距、 前胸背板宽、 中胸气门长和体长等5项形态指标, 利用频次分析的统计方法, 测定了栗山天牛幼虫的龄数。结果表明: 栗山天牛幼虫有6龄, 雌雄性幼虫龄数相同。上颚长、 主单眼间距和前胸背板宽3项指标均可用于分龄, 中胸气门长和体长变异较大, 不宜用作幼虫龄数划分。利用种群众数龄期法计算1-6龄幼虫的平均龄期分别为9.25, 266.85, 48.09, 51.29, 260.33和385.71 d, 幼虫期共1 021.52 d。在我国东北地区, 自然条件下栗山天牛世代发生非常整齐而且高度同步, 完成1代发育需跨越4个年份, 幼虫经历3次越冬, 第1年以2-3龄幼虫越冬, 第2年主要以4-5龄幼虫越冬, 第3年全部以末龄幼虫越冬。研究结果进一步明确了栗山天牛幼虫期的生物学特性, 为生产上合理防治该害虫提供了参考依据。     

北京地区六种叶甲幼虫形态比较研究

通过检索表把北京地区常见的6种叶甲：榆绿毛萤叶甲、褐背小萤叶甲、榆黄萤叶甲、柳圆叶甲、菜无缘萤叶甲、十星瓢萤叶甲的幼虫区分开来。然而利用幼虫侧面图、头部正面图、足的侧面图和幼虫背面图等形态比较,进一步深入体现出它们之间的异同。为农林植保工作者提供参考。     

曲牙土天牛幼虫的生长发育及其与寄主植物的关系

为了探索化橘红主要蛀干害虫曲牙土天牛幼虫的生长发育及其与寄主植物之间的关系,提供综合治理该虫的理论依据,作者于田间利用化橘红、白木香和短萼白花灰叶豆木段,分别饲养曲牙土天牛幼虫,分析该虫的生长发育趋势,同时对幼虫的体长、体重和前胸背板宽进行了比较研究。结果显示：曲牙土天牛在化橘红规范化种植基地1~2年发生1代,以个体大而重的幼虫当年化蛹的概率较高,而个体小而轻的幼虫死亡率偏高。该虫在3种寄主植物上都能完成生活史,以化橘红木段饲养的该虫幼虫虫体大小和体重增长率显著高于其它两种植物。     

松墨天牛的生物学特性Ⅱ:生活习性

2002—2004年在厦门同安进行松墨天牛的饲养及观察。结果表明,松墨天牛在厦门以2a3代为主,少数1a2代,2a3代的松墨天牛有3个羽化高峰期,1a2代的有2个高峰期,二者的第1个羽化盛期在4月份相叠加,所以4月份的成虫数量最多,占全年羽化成虫总数的31％,此后一直到8月下旬,都有较多的成虫羽化。羽化后的成虫从蛹室向外咬圆形的羽化孔道飞出,有的当天即取食,有的时隔1—2d取食,最初喜食当年生松枝的嫩皮,个别也取食微量松针,性成熟后食1-3年生松枝、树皮补充营养,而且昼夜均取食。成虫补充营养5—7d后开始交尾,可多次重复交配,成虫的产卵与交尾是交错进行的,卵产于刻槽内靠形成层的韧皮部,一个刻槽一般产1粒卵,个别的有2—3粒,大多数无卵,无卵的刻槽约占60％-70％。雌成虫咬啃刻槽后常在树干上留下泪滴状松脂。幼虫孵化后取食松树内皮和韧皮部,在树皮外可见白色纤维状、褐色粉末状排泄物,3龄以后蛀入木质部,老熟后做一椭圆形蛹室化蛹,蛹期8—15d。世代重叠现象明显,几乎全年可见幼虫,以3—5龄幼虫在蛀道内越冬或以低龄幼虫在韧皮部越冬。     

双条杉天牛幼虫龄数的划分(鞘翅目:天牛科)

双条杉天牛 Semanotus bifasciatus Motschulsky 是危害我国侧柏 Platycladus orientalis 和圆柏 Sabina chinensis 的重要钻蛀性害虫,其幼虫龄数及最佳分龄指标的确定是进一步研究其生物学特性、发生规律的基础.本研究通过室内木段饲养法获取不同发育阶段的双条...     

褐梗天牛幼虫和成虫空间分布的地统计学研究

褐梗天牛(Arhopalus rusticus Linnaeus)是一种对松、杉、柏等林木危害非常严重的蛀干害虫,主要危害针叶树的衰弱木以及火灾后的枯立木,是继松褐天牛之后携带拟松材线虫能力最强的蛀干害虫。为了更好地控制其危害,深入地研究其种群空间格局,运用地统计学方法分析了3块受害程度不同的油松林内褐梗天牛幼虫和成虫的空间分布特性。结果表明:3种受害程度不同的林分内,褐梗天牛的危害具有显著差异,轻度受害林分内有虫株率为30.8%,中度受害林分内有虫株率为44.3%,而重度受害林分内高达78.3%。根据变异函数曲线图分析得知:轻度受害林、中度受害林和重度受害林内褐梗天牛幼虫种群空间分布最优拟合模型分别为高斯模型、高斯模型和指数模型,成虫的种群空间分布最优拟合模型均为线性模型。在3种林分中褐梗天牛幼虫数量具有明显的空间依赖性,轻度受害林、中度受害林和重度受害林内幼虫数量的空间依赖范围分别是19.10、11.97、61.98m,其空间连续性强度分别是0.646、0.784和0.500;成虫的空间依赖范围分别是43.08、43.23、44.17m,其空间连续性强度分别是0.044、0.021和0.171,但其成虫的数量在空间呈随机分布,没有表现出空间依赖性。根据垂直分布图分析得出:褐梗天牛幼虫和成虫在油松上主要集中聚集在某个高,然后随着高度增加密度降低,随着高度接近地面密度也降低。用Kriging插值法生成的空间分布图显示幼虫在空间分布上具有明显的聚集性,其聚集中心主要集中在林地中心,由林地中心株向整个林地扩散,而成虫则表现为随机分布。     

Metabolic response of cerambycid beetle (Morimus funereus) larvae to starvation and food quality

The response of xylophagous Morimus funereus larvae to a direct change of diet demonstrated that the larvae from nutrient-poor substrates, e.g. oak, are very sensitive to such a change. Depending on dietary protein quality and quantity, an increase of proteolytic activity, i.e. an intensified protein metabolism accompanied by changes in body mass gain, was observed. At the same time, amylolytic activity was usually decreased. In the larvae reared on Robert's diet, sensitivity to the switch in diet was lower at the level of proteolytic enzymes that remained at the control level, while amylolytic activity was elevated. If the switch to a new diet was preceded by 7-day-starvation that disturbed nutritional homeostasis, the response of the larvae was similar to that recorded upon a direct switch only after short-term feeding (24 h) upon starvation. Differences in the response to changes in the diet of the larvae from nature, those reared under laboratory conditions and those of different physiological status could be ascribed to plasticity in the expression of the genes coding for proteases and their isoenzymes, as well as to the multi-functionality of some neurosecretory neurons, synthetic products that participate in the regulation of digestive enzyme activities.     

A note on stridulation in some cerambycid beetles and its possible relation to ventilation

An account is given of stridulation in Petrognatha gigas and Phryneta spinata and of the occurrence of prothoracic stridulatory activity and accompanying abdominal movements in Strangalia maculata.     

Mechanical device for morphological and orientation analysis of biological structures

A simple mechanical device for different kinds of morphological analysis is suggested. It consists of a binocular microscope, a luminiscent illuminator, a coordination table with a disc-chuck (0-360 degrees) and a nest for disposing the test systems and the light or electronmicroscopic negatives (6 x 9 and 9 x 12). The analysis is performed by means of visual scanning of the negatives, by counting the number of crossings of the structure with the test system knots and by registration of the measurements by a key recorder. For orientation analysis the microscope is supplied with a goniometer (0-360 degrees) and an oculometer with a cross of filaments.     

Seasonality,crop type and crop phenology influence crop damage by wildlife herbivores in Africa and Asia

Wildlife species damaging crops can cause substantial losses to farmers and at the same time create negative attitudes against wildlife and conservation efforts that may result in negative interactions against wildlife and lead to human-wildlife conflicts (HWCs). For the analysis of negative interactions between humans and terrestrial wildlife species, a globally applicable scheme for monitoring was developed and applied over 6 years in study areas of two Asian (Nepal and India) and two African (Zambia and Tanzania) countries. Factors influencing crop consumption by eight different groups of herbivores were monitored and analyzed using generalized linear models. Seasonality, crop availability, type and the phenological stage of the crop seem to play an important role in the crop damaging behavior of herbivores. Crop consumers such as elephants (Loxodonta africana and Elephas maximus), zebra (Equus quagga spp.) and boars/hogs (Sus scrofa, Potamocherus larvatus and Phacochoerus africanus) show preferences for harvested and/or maturing crops. Rhinos (Rhinoceros unicornis) and antelopes/deer (Taurotragus oryx, Aepyceros melampus, Boselaphus tragocamelus and Axis axis) damage the highest numbers of fields with crops at an intermediate growth stage. The findings of this study can inform management of HWCs in areas where people and wildlife coexist. Furthermore, this study demonstrates the benefits of standardized HWC assessments in order to compare data from different continents and between different species to be able to draw generalized conclusions for the management of HWC.     

Differential crop damage by healthy and nucleopolyhedrovirus-infected Mamestra brassicae L. (Lepidoptera: Noctuidae) larvae: a field examination

Baculovirus infection in Lepidoptera can alter both larval mobility and feeding rates, which can in turn affect pathogen transmission and dispersal in the field. We compared the damage to cabbage plants in the field caused by healthy and nucleopolyhedrovirus-infected Mamestra brassicae L. (Lepidoptera: Noctuidae) larvae released as second and fourth instars. There was no significant difference in plant consumption by healthy and infected larvae for the first 4 days after release. From day 5 onwards, infected larvae caused significantly less defoliation. This pattern was similar for larvae at both larval instars. Defoliation was greater for fourth instars throughout the experiment.     

The proventriculus of some trichopterous larvae

A well-developed proventriculus is present in larvae of the Polycentropodidae and Hydropsychidae. Its structure varies greatly between species but there is a common bilaterally symmetrical pattern based on a pair of posterior ventral folds. These are continuous with the sides of a ventral gap in the fold of foregut that invaginates into the midgut. Modifications of this basic structure to form either triturating or filtering devices occur, and there are others where the mechanism of food treatment is not immediately apparent and may be complex.     

Tissue damage and haematophagia due to praniza larvae (Isopoda: Gnathiidae) in some aquarium seawater teleosts

Over a 5 yr period, severe infestations due to Gnathia vorax larvae affecting different teleosts have been registered at the Civic Aquarium of Messina, Italy. Here, the damage caused by these parasites is evaluated from a macroscopical and histopathological point of view. We also attempt to evaluate the amount of blood sucked up by a single parasite and make some observations about the haematophagia. The histopathological changes confirm mucosal electrolytic failure as the main problem, even though the mean value of blood sucked up by a single parasite, about 1.9 mg, suggests that haematophagia may play an important role in the pathogenesis of such infestation. In conclusion, it was found that the G. vorax larvae caused 2-fold damage that was responsible for the death of the fish. Little by little, the parasitic problem was successfully removed by washing the tank, using fresh water rather than costly and dangerous chemotherapeutans.     

Disinfection of wooden structures contaminated with Paenibacillus larvae subsp. larvae spores

AIMS: The aim of the study is to examine the disinfection of wood contaminated with Paenibacillus larvae subsp. larvae spores, in order to find a practical decontamination method for hive materials. METHODS AND RESULTS: The number of viable spores recovered after the treatment, on the surface by swabbing, and in the deeper parts of the wood by scraping, was used to test the efficiency of the disinfection. Our results indicate that chemical disinfection is only complete when high concentrations (> 50%) of the disinfectant are used. Heat treatment in general was found to be very effective. The scorching of wood was not satisfactory as it only killed spores at the surface. CONCLUSION: Complete disinfection is only possible with some heat treatments or by using high concentrations of chemical disinfectants. SIGNIFICANCE AND IMPACT OF THE STUDY: This study puts forward some methods that can provide complete decontamination, which is necessary for an effective control of American foulbrood disease.