Studies Of Taxonomy, Geographic Distribution In Gynaephora Genus And Life-history Strategies On Gynaephora Menyuanensis

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...