【作者】 严林；

【导师】 王刚；

【作者基本信息】 兰州大学 ， 生态学， 2006， 博士

【摘要】 本研究从青藏高原北部高寒草地重要害虫门源草原毛虫(Gynaephora menyuanensis Yan et zhou)的地理分布、形态特征入手，应用昆虫生态学研究方法，通过野外调查和室内试验，系统研究了门源草原毛虫的生活史特征、栖息地环境因子对门源草原毛虫生活史特征的影响。旨在探明门源草原毛虫在青藏高原极端环境条件下的生活史适应对策，为了解该害虫种群动态机制和制定科学有效的控制方法提供科学依据。研究结果如下： 1、首次对草原毛虫属分类及地理分布进行了研究。目前全世界草原毛虫属昆虫有15种，主要分布于北半球的高山，以及北极的冻土地带，尤以高原地区较多。亚洲分布13个种、欧洲分布3个种、北美1个种、北极2个种。亚洲草原毛虫种类集中分布在青藏高原(8个种)和帕米尔高原(4个种)，两个高原是世界草原毛虫物种多样性中心。目前中国分布有8个种，全部分布于青藏高原的高寒草地上，是该地区草地生态系统中的主要害虫。8个种中，青海分布6个种、西藏2个种、四川3个种、甘肃2个种。根据草原毛虫成虫翅和生殖器的特征，以及幼虫形态特征，建立了草原毛虫属世界物种分类检索表(幼虫和成虫分种检索表)。 2、新种门源草原毛虫的形态特征：成虫，雌雄成虫具有性二型特征，主要是雌雄成虫在外部形态、个体大小和翅的有无上的差别。雄成虫，体长8.56±0.18mm(范围7.50～9.20mm)，翅展24.64±0.58mm(范围20.50～28.00mm)；触角长度不超过前翅的1／2；前翅正面由黑褐色鳞片组成翅的底色，中室端横脉内有一较大的土黄色或桔黄色斑纹，外横线明显、土黄色、从翅前缘伸至后缘呈反“s”形弯曲，到达后缘2／3处；后翅中部有黑褐色小斑。雌成虫无翅，体长13.60±0.34mm(范围9.68～15.96mm)，宽6.71±0.25mm(范围4.92～8.24mm)，整个身体黄色，密被棕灰色短茸毛。 卵，直径1.37±0.03(范围1.1～1.44mm)，高1.03±0.02mm(范围0.8～1.2mm)，偏球形、白色。卵壳电镜扫描特征是，受精孔管6～7条，受精孔花饰小叶呈令箭形、3圈，内圈花瓣9～14片，受精孔花饰外围是6边形网状花纹6-8层。 幼虫，幼虫也表现出性二型，主要是雌雄性幼虫在个体大小和虫龄方面的差别。老龄幼虫雄性体长18～20mm，雌性体长25～33mm，头红色，被黑色长毛，足、前胸背板和肛上板的颜色均为黑色。幼虫虫龄，雄性幼虫为6龄，雌性为7龄；野外采集的幼虫一至七龄的头壳宽分别是0.68、0.91、1.22、1.58、2.06、2.69和3.45mm，室内饲养的幼虫一至七龄的头壳宽分别是0.67、0.87、1.17、1.54、2.00、2.59 and 3.24mm。幼虫各生物学参数之间的关系是，头壳宽与摄食量为显著的直线相关关系。而头壳宽与体重，虫龄与头壳宽、体长、体重均呈显著的指数关系。头壳宽与体长，虫龄与摄食量呈显著的幂函数关系。 蛹，同样表现出性二型，主要是雌雄蛹在外部形态、颜色和个体大小方面的差别。雌蛹平均体长13.86±0.45mm(范围9.78～17.08mm)，体宽8.17±0.36mm(范围4.54～8.28mm)(图3-3，6b)。雄蛹平均体长11.80±0.24mm(范围9.20～11.50mm)，体宽4.48±0.14mm(范围3.62～5.80mm)。 3、生活史特性 主要发生在高寒草甸草地，一年发生一个世代，以滞育的一龄幼虫越冬，翌年3月中下旬至4月上旬开始活动，当植物幼芽出现时，一龄幼虫开始取食，4月下旬至5月初进入二龄幼虫期，5月中下旬进入三龄幼虫期，6月上中旬进入四龄幼虫期，6月中下旬进入五龄幼虫期，7月上中旬进入六龄幼虫期，7月中下旬至8月上中旬进入七龄幼虫期，7月中下旬结茧化蛹，7月下旬至8月下旬为蛹期，8月中下旬至10月初为成虫期，8月中下旬至9月上旬为交配期，8月中下旬至9月上中旬产卵，9月中下旬至10月上中旬一龄幼虫孵化，进入滞育越冬。门源草原更多还原

【Abstract】 Life-history Strategies not only are a key academic problem in population ecology, but also have an important prospect in applications. There are many reports on effects of single or synthetic factors on strategies life-history in insect, but it has not been fully investigated yet. The life-history strategies of insect species is impacted by various stress factors in habitat environment. In unfavorable environment of Tibetan-Qinghai plateau, what traits of life-history will present in the insects have not been paid attentions.In this thesis, life-history traits, such as the developmental time, survival, individual size and fecundity in larval stges, pupal stage, adult stage and egg stage, and effect of environmental factors to these life-history traits in their habitat were studied systematically in Gynaephora menyuanensis. The ecological methods were used in this study. The aim of this work was to probe into the life-history strategies of the Gynaephora menyuanensis under extremely environment of Tibetan-Qinghai plateau, and to understand mechanism of population dynamic, and to provide a sciences evidences for the management of the insect pest. The obtained results showed:1.Taxonomy and geographic distribution of Gynaephora genus were first studied. In views of the advance of research on the genus Gynaephora and according to the specimens collected from Qinghai-Tibetan Plateau, 15 species and 2 subspecies in the world are recognized currently. The geographic distribution pictures of all the 15 species have been drawn. A key to the species of Gynaephora (adult and larvae) is provided. The relationship between the environmental evolution in Qinghai-Tibetan Plateau and the rich species of Gynaephora are discussed.2. Appearance. Adults of this species were sexual dimorphism. Males. Antennal length was shorter than a half of forewing. Wings blackish-brown with two conspicuous ground-yellow maculae on the median cell of forewing and S-shaped outer transversal line with ground-yellow reached two-thirds of posterior margin, and hindwing with a small brownish-black spot on the center of upper and lower surfaces. Average wingspan 24.64 ± 0.58 mm (range = 20.50-28.00mm), and male adults averaged 8.56 ± 0.18 mm long (range = 7.50-9.20mm) by 3.85±0.12 mm wide (range = 3.50-4.80mm). Female. Body without wing was yellow, broadly oval shape with densely brownish-gray short pappus, and the head capsules were black. Female adults averaged 13.60+0.34 mm long (range = 9.68-15.96mm) by 6.71 ± 0.25 mm wide (range = 4.92-8.24mm).Egg. Fresh eggs were smooth, flat spheroid with white, and anterior pole slightly pitted. Fertilized eggs turned from whitish to lightly gray and anterior pole appeared black dot near eclosion. Egg size was 1.37±0.03 (range= 1.1 -1.44 mm, diameter) × 1.03 ± 0.02 mm (range=0.8-1.2 mm, height). Under the scanning electron microscope, the characteristics of the chorionic structure of G. menyuanensis were as shown in : The surface of chorion is wrinkled, pitted, and overlain with conspicuous, irregularly polygonal cells with 8-7 layers. Anterior pole of egg is micropylar region where there are 8-8 fertilization micropyles, 8-7 micropylar tubes. The micrpyle is distinct, surrounded by 2-3 circle rosette of irregular, petal-shaped reticulations. Aeropyles are inconspicuous, slightly domed, and appear at junction of polygonal cells in 8-8 polygonal cellsLarva. The head capsules were red in the full-grown larva, larval abdominal pedes, pronotum, epiproct, and scopulae were black. Larval body surface were tufted with black spinulose hairs. Full-grown larvae 18-20 mm (male) or 25 -33 mm long(female). Larvae have 6 instars in the male or 7 instars in the female. Mean head capsule widths were 0.68, 0.91, 1.22, 1.58, 2.06, 2.69, and 3.45mm in field-collected larvae and 0.67, 0.87, 1.17, 1.54, 2.00, 2.59, and 3.24 mm in laboratory-reared larvae for 1st through 7th更多还原