四川冶勒自然保护区树皮下的甲虫

作者于2005年7月~9月在冶勒自然保护区对生活在干枯、腐败树皮下的甲虫进行调查研究,共采集到218号标本,初步鉴定出20个科。以隐翅虫科Staphylinidae个体数最多,135头,占总数的61.9%,步甲科Carabidae次之,计29头,占13.3%。     

Stand characteristics and downed woody debris accumulations associated with a mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreak in Colorado

Lodgepole pine (Pinus contorta Dougl. ex Loud.)-dominated ecosystems in north-central Colorado are undergoing rapid and drastic changes associated with overstory tree mortality from a current mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreak. To characterize stand characteristics and downed woody debris loads during the first 7 years of the outbreak, 221 plots (0.02 ha) were randomly established in infested and uninfested stands distributed across the Arapaho National Forest, Colorado. Mountain pine beetle initially attacked stands with higher lodgepole pine basal area, and lower density and basal area of Engelmann spruce (Picea engelmannii [Parry]), and subalpine fir (Abies lasiocarpa (Hook.) Nutt. var. lasiocarpa) compared to uninfested plots. Mountain pine beetle-affected stands had reduced total and lodgepole pine stocking and quadratic mean diameter. The density and basal area of live overstory lodgepole declined by 62% and 71% in infested plots, respectively. The mean diameter of live lodgepole pine was 53% lower than pre-outbreak in infested plots. Downed woody debris loads did not differ between uninfested plots and plots currently infested at the time of sampling to 3 or 4–7 years after initial infestation, but the projected downed coarse wood accumulations when 80% of the mountain pine beetle-killed trees fall indicated a fourfold increase. Depth of the litter layer and maximum height of grass and herbaceous vegetation were greater 4–7 years after initial infestation compared to uninfested plots, though understory plant percent cover was not different. Seedling and sapling density of all species combined was higher in uninfested plots but there was no difference between infested and uninfested plots for lodgepole pine alone. For trees ≥2.5 cm in diameter at breast height, the density of live lodgepole pine trees in mountain pine beetle-affected stands was higher than Engelmann spruce, subalpine fir, and aspen, (Populus tremuloides Michx.), in diameter classes comprised of trees from 2.5 cm to 30 cm in diameter, suggesting that lodgepole pine will remain as a dominant overstory tree after the bark beetle outbreak.     

Aerially applied verbenone-releasing laminated flakes protect Pinus contorta stands from attack by Dendroctonus ponderosae in California and Idaho

We tested a new formulation of verbenone, an antiaggregation pheromone of the mountain pine beetle (Dendroctonus ponderosae Hopkins) (Coleoptera: Curculionidae: Scolytinae), for area-wide protection of lodgepole pine (Pinus contorta Douglas ex Loudon) stands in the western United States. Helicopter applications of verbenone-releasing laminated flakes were made at the rate of 370 g of active ingredient/ha to two sites, one in California and one in Idaho, during summer 2005. Each site consisted of five 20.23-ha treated plots and five matching 20.23-ha untreated plots. We assessed D. ponderosae flight into study plots using traps baited with aggregation pheromones and we tallied D. ponderosae attack rates on P. contorta trees in treated and control plots before and after application. There were no significant differences between numbers of D. ponderosae trapped on treated and control plots. However, a significantly smaller proportion of P. contorta trees was attacked in treated plots than in control plots at both sites; the attack rate in untreated stands was roughly three times that of treated stands in both California and Idaho, even at this low application rate. Furthermore, attack rate in 2004 was a significant explanatory variable for the response in 2005 regardless of treatment in both California and Idaho. There was no significant treatment effect at either site on attraction of Temnochila chlorodia (Coleoptera: Trogositidae) Mannerheim, a key predator of D. ponderosae, to the prey aggregation pheromone.     

2008年河口地区橡胶树寒害后小蠹虫严重危害及防治

2008年,云南河口植胶区继严重寒害后首次发生橡胶树小蠹虫严重为害,经调查证实橡胶树遭严重寒害是诱发小蠹虫大发生的直接原因;通过生产性防治试验,提出新的、有效实用的防治措施。     

Short-term community-level response of arthropods to group selection with seed-tree retention in a northern hardwood forest

We examined the short-term effects of group-selection harvesting with seed-tree retention on ground-dwelling and bark-dwelling arthropod communities in a northern hardwood forest in the Upper Peninsula of Michigan. Arthropods were sampled in 16 group-selection openings and 8 closed canopy reference plots. Two opening sizes were examined—radii of 0.5 (320 ± 27 m², n = 8) and 1.0 (1217 ± 62 m², n = 8) times the mean canopy height (22 m). Each opening and reference plot was centered on a single Betula alleghaniensis Britt. (yellow birch). Ground-dwelling arthropods were sampled using pitfall traps that were opened for two 1-week periods (rounds 1 and 2), and bark-dwelling arthropods were sampled with sticky traps attached to the centrally located B. alleghaniensis trees. Family-level diversity of ground-dwelling arthropods was lower in reference plots than in the openings, but the only significant difference occurred during round 2, between the matrix and large openings (P < 0.01). During both sampling periods, the ground-dwelling community exhibited a distinct clustering of family-level composition along environmental gradients such as opening size. Families such as Staphylinidae (rove beetles) and Trombidiidae (red velvet mites) were not favored by higher canopy openness while families such as Acrididae (grasshoppers) and Lycosidae (wolf spiders) were captured more in openings than in the forest matrix. Landing rates of wood-boring insects such as Buprestidae (metallic wood-boring beetles) and Xiphydriidae (wood wasps) were significantly higher on seed trees in group-selection openings than in reference plots (P < 0.05). Our results suggest that integrating group-selection openings within northern hardwood forests can lead to an increase in the family-level diversity of ground-dwelling arthropods, at least in the short term. Furthermore, seed trees left in such openings may be more attractive to bark- and wood-boring insects, which warrants further investigation into the susceptibility of these seed trees to damage by certain insect pests.     

Macrophytes promote aquatic insect conservation in artificial ponds

相似文献   

树木抗性与小蠹虫生存策略的进化

小蠹虫对寄主树木的入侵危害不仅受到树木原生性抗性的直接影响 ,而且小蠹虫在寄主树木组织内的定居繁衍也受到寄主树木诱导性抗性的制约。寄主树木抗性的强弱决定小蠹虫入侵寄主树木的数量 ,也促使小蠹虫与特定的真菌共生 ,真菌通过对寄主树木生理生化代谢的影响 ,以削弱寄主树木抗虫性 ,从而为小蠹虫在寄主树木组织内的定居创造必备的生存条件。同时小蠹虫为适应真菌的共生和寄主树木的抗虫性 ,促使小蠹虫生存繁衍策略高度进化 ,从而形成小蠹虫—共生真菌—寄主树木三者协同进化共生的关系     

利用捕食性天敌大唼蜡甲防治大小蠹属害虫的研究进展

综述云杉大小蠹的重要捕食性天敌昆虫大唼蜡甲在国内外的研究、应用情况,对大唼蜡甲的生物学和习性、化学生态研究情况、人工大量饲养和储存方法进行详细介绍,并对法国、英国等国家运用大唼蜡甲防治云杉大小蠹的实践进行总结.根据其特性及近年来国际生物防治理论的新发展,以引入大唼蜡甲对已传入我国的重大外来入侵害虫--红脂大小蠹进行生物防治的成功实践为例,讨论引入大唼蜡甲防治其他针叶树大小蠹的可能性和必要条件以及应采取的策略.     

热改性橡胶木防止粉蠹虫害分析

考察热改性橡胶木在海南岛自然环境下遭受粉蠹虫害的程度、热改性前后木材淀粉和游离糖含量变化。结果表明:橡胶木素材未经过传统的硼化物加压浸注防腐处理,1 a后遭受粉蠹虫蛀,185℃/3 h和215℃/3 h热改性的炭化橡胶木在海南自然条件下放置3.5 a,试材未受到粉蠹虫危害。橡胶木素材中淀粉含量为6.69%,蔗糖占索氏抽提成分比例9.96%,经过高温热改性后,其淀粉与蔗糖含量大幅度降低,200℃/3 h淀粉含量降低为1.03%、蔗糖占索氏抽提成份比例降低为0.67%。     

中国花天牛亚科昆虫名录（续）

列出了我国花天牛亚科昆虫种类名录。共计２８６种（含亚种），其中包括２个新种和６个中国新记录种，以及一批省级新记录。