甘肃祁连山国家级自然保护区森林昆虫天敌种类调查（二）

本文报道甘肃祁连山国家级自然保护区鞘翅目(Coleoptera)昆虫天敌12科97种。     

Responses of community structure,diversity, and abundance of understory plants and insect assemblages to thinning in plantations

Identifying effective management operations for plantations is important for conservation of biodiversity in a plantation-dominated landscape. We tested whether pre-commercial thinning influenced community structures and could be an effective strategy for increasing diversity and abundance of plants and animals in plantations. We designated thinned and unthinned study stands in Japanese cedar (Cryptomeria japonica) plantations and compared the communities of understory vegetation, bees, butterflies, hoverflies, and longhorn beetles 1 and 3 years after thinning. The analyses of vegetation showed that pre-commercial thinning affected community structure, but species richness and vegetation abundance were not significantly affected. Thinning affected insect community structure, and both species richness and abundance of all insect groups increased 1 year after thinning. However, 3 years after thinning, significant differences only remained in the species richness of bees and the abundance of bees, butterflies, and hoverflies. These results suggest that pre-commercial thinning in plantation stands influences the community structure of understory vegetation and can be an effective way to increase the diversity and abundance of some insect groups in the short term. However, the results also suggest that the duration of the operational effects of pre-commercial thinning varies among insect groups; thus, the variable effects of pre-commercial thinning should be carefully considered in the conservation-based management of plantation stands.     

宁夏拟步甲的区系组成和分布特征

宁夏回族自治区已知１８族、３３属８３种拟步甲，以此作为研究材料论证了该类昆虫在宁夏的区系分布和组成、区域分布和生态地理分布特点。在区系分布方面，荒漠成分有７３种（占８９％），黄土高原成分有２２种（占２７％），两种成分共有的１３种。在区系特殊上，国内蒙新区成分有７１种（占８６．６％），华北成分有３５种（占４２．７％），青藏成分有７种（占８．５％），东北成分和华南成分分别有９种（占１１％）和３种（占３     

Bacillus thuringiensis insecticides in crop protection — reality and prospects

Bacillus thuringiensis (Bt) has been the leading biopesticide against lepidopterous pests since 1959. In the 1990 s the following developments contributed to increased rational uses of Bt: (1) natural and recombinant Bt products were developed to broaden the insect host range in pest management programs; (2) new formulations based on conventional or genetically engineered encapsulation of the toxins and/or feeding stimulants to increase ingestion and, in turn, the efficacy of the microbe; (3) screening of the interactions of Bt with insect herbivores and plant allelochemicals or natural enemies of the pests, to aid the formulation of biological control strategies; and (4) knowledge and management of insect resistance to Bt. The prospects for Bt insecticides will be described and discussed.     

Digestion of microbial biomass, structural polysaccharides, and protein by the humivorous larva of Pachnoda ephippiata (Coleoptera: Scarabaeidae)

In order to investigate whether microbial biomass and its residues are nutrient and energy sources for humivorous beetle larvae, we carried out feeding trials using soil supplemented with ¹⁴C-labeled fungal biomass (Penicillium chrysogenum), bacterial biomass (Bacillus megaterium), fungal or bacterial structural polysaccharide (chitin, peptidoglycan), bacterial protein, or cellulose, taking the larva of the cetoniid beetle Pachnoda ephippiata (Coleoptera: Scarabaeidae) as a model of a humus-feeding beetle larva with a highly alkaline gut. The results showed that gut passage strongly stimulated the mineralization of the structural polymers. The stimulatory effect correlated positively with the recalcitrance of the preparation in the control soil, and was accompanied by a transformation of the residual radiolabel to alkali-soluble and acid-soluble products. The solubility increase was highest in the extremely alkaline midgut. High-performance gel-permeation chromatography demonstrated that the changes in solubility were accompanied by reciprocal changes in the molecular weight of the residual material and that the residual material in the fecal pellets was more humified than in the control soil. The amount of radiolabel recovered from the body and hemolymph of the larvae indicated that microbial biomass and its structural components were assimilated more efficiently than cellulose, which supports the hypothesis that microorganisms and the nitrogenous components of humus are an important dietary resource for humivorous soil macroinvertebrates.     

中国虎天牛族区系初步研究(鞘翅目:天牛科:天牛亚科)

在已有标本采集记录和资料的基础上,通过对我国已记载的18属370种7亚种虎天牛族昆虫进行初步区系分析,基本明确了中国虎天牛族生物多样性及地理分布状况。在属的组成中,若按区系成分比较,北方区系成分4属,南方区系成分10属和南北区系成分不明的4属,属的比例各为22．22％,55．55％和22．22％。不论是从属的数量上还是从属的容量上来考虑,南方区系成分占优势;在种的组成中,北方区系成分81种3亚种,占总数的22．28％;南方区系成分258种3亚种,占总数的69．23％;南北区系特征不明的27种1亚种,占总数的7．43％;全国分布的4种,占总数的1．06％,南方区系成分几乎占了我国区系成分的2／3。     

鞘翅目昆虫遗传多样性研究现状及展望

通过对国内外十多年来相关资料的整理,从染色体多态性、蛋白质多态性和DNA多态性3个层次对鞘翅目昆虫的遗传多样性研究现状进行了综述,并展望了分子生物学技术在昆虫遗传多样性研究中的前景。     

中国筒天牛属二新种记述(鞘翅目:天牛科:沟胫天牛亚科)

记述沟胫天牛亚科筒天牛属2新种,锥胸筒天牛Oberea conicus sp.nov.和指突筒天牛Oberea fingeriventris sp.nov..新种模式标本分别保存于西南农业大学植保系昆虫标本馆和南开大学生物系昆虫标本室.     

Susceptibility of adult Coccinella septempunctata (Coleoptera: Coccinellidae) to insecticides with different modes of action

Five insecticides (pyriproxifen, imidacloprid, deltamethrin + heptenophos, lambda-cyhalothrin and Bacillus thuringiensis Berliner subsp. tenebrionis) were examined in the laboratory for their acute detrimental side-effects at field rates on adult seven-spot ladybird beetle, Coccinella septempunctata L. The toxicity of the preparations was determined by measuring the acute surface contact effects (dried spray on leaves of Philadelphus coronarius L.), except for B. thuringiensis where mixed pollen was treated. Four to six concentrations were tested (pyriproxifen 12.5, 25, 50, 100, 200, 400 mg AI litre(-1); imidacloprid 62.4, 125, 250, 500 mg AI litre(-1); deltamethrin + heptenophos 26.4, 53.1, 106.3, 212.5 mg AI litre(-1); lambda-cyhalothrin 1.1, 3.4, 10, 30 mg AI litre(-1); B. thuringiensis 1.5, 3.0, 12.0, 48, 192, 768 mg AI litre(-1)), with 22 adults exposed per concentration. All tests were conducted in the laboratory of the Plant Protection Department (University of Debrecen, Hungary) at 22-25 degrees C, 40-60% RH, under a 16:8 h light:dark photoperiod in 1998-1999. Data were analyzed by probit analysis, probit transformation and analysis of variance. According to different categories of evaluation, pyriproxifen, imidacloprid and B. thuringiensis subsp. tenebrionis seem to be safe for C. septempunctata adults but the other two preparations were moderately harmful to them, which requires further semi-field or field tests to measure their real effect under field conditions.