栎空腔瘿蜂种群动态及与气象因子的关系

采用野外系统调查和室内试验相结合的方法,调查了栎空腔瘿蜂Trichagalma glabrosa及其虫瘿种群数量动态,并分析了虫瘿密度及种群死亡率与气象因子的关系。结果表明:栎空腔瘿蜂初始期虫瘿的高峰期出现在5月中旬,成长期虫瘿的高峰期出现在6月上旬,成熟期虫瘿高峰期出现在6月下旬到7月上旬;栎空腔瘿蜂化蛹高峰期为9月下旬,羽化高峰期为11月下旬。4月气温、4月中旬气温和降雨量对虫瘿密度有着重要影响,其相关系数分别为0.720,0.854和-0.906。5月的总降雨量对种群死亡率有显著影响,相关系数达到了0.889。     

细梢小卷蛾种群动态与风险分析

细梢小卷蛾Rhyacionia leptotubula Liu et Bai是危害华山松Pinus armandi的重要蛀梢害虫,在滇东北高海拔地区大面积发生.在滇东北具有代表性的地区设立固定样地,连续3 a调查研究了细梢小卷蛾的危害状况和种群变动情况,发现该虫的危害逐年加重,种群呈上升趋势,对华山松的生长影响较大.采用区域性有害生物风险分析方法对细梢小卷蛾进行定性与定量风险分析,结果表明:细梢小卷蛾的寄主植物分布范围广,适生区广且根除难度大,对云南林业的潜在威胁较大;细梢小卷蛾风险指数R为1.90,在云南属中度危险性有害生物,林业部门应重视该虫的监测与防治工作,阻止其更大范围的扩散蔓延.     

Shrubs facilitating seedling performance in ungulate-dominated systems: biotic versus abiotic mechanisms of plant facilitation

Shrubs are important microsites that facilitate seedling performance in abiotically stressed environments. However, shrub facilitation might work differently in ecosystems with high biotic stress (e.g., ungulate-dominated environments). We wonder whether ungulates through their preferences for different shrubs affect the facilitation process of seedlings, and whether this process remains consistent across different levels of abiotic stress. We study seedling performance (survival and growth) of a Mediterranean oak (Quercus pyrenaica) in three microsites (open, preferred and non-preferred shrubs by ungulates) for two contrasting climatic environments and throughout a complete growing season (increasing abiotic stress). Overall, there was a positive effect of shrubs in seedling survival. We found a microsite effect on seedling growth but this effect differed depending on the abiotic environment, with seedlings growing better in open microsites in the less stressful site. The larger abiotic context (climate) played an important role in determining which microsite is the most favorable for seedling growth but not necessarily for the eventual survival of seedlings. Wild ungulates started to damage seedlings early in the growing season, whereas abiotic stress (desiccation) affected mostly those plants that were not previously attacked by animals, showing the hierarchical effect (earlier and longer effect) of the biotic over the abiotic mortality agents. Non-preferred shrubs worked better as nurse shrubs only under high ungulate pressure. From the abiotic perspective, preferred and non-preferred shrubs did not apparently differ in the facilitation effect. Importantly, we found a greater facilitative effect of shrubs on the survival than on the growth of seedlings.     

Influence of altitude on adult emergence and dynamics ofKaltenbachiola strobi (Winnertz) (Diptera: Cecidomyiidae) populations and its parasites in the Tatra National Park, Poland

A field study onKaltenbachiola strobi (Winnertz) (Diptera: Cecidomyiidae), was carried out between 1987 and 1993 in the highest mountain range in the Western Carpathians located within the Tatra National Park, in southern Poland. Rearing and analysis of 5 780 cones ofPicea abies (L.)Karst., collected from trees growing at different altitudes, yielded 30,478 individuals ofKaltenbachiola strobi, which infested 89.10% of the cones. In case of 29.81% of cones there were more than 20 larvae ofK. strobi per cone. It was shown thatK. strobi in the Tatra Mts. is more abundant in spruce stands of the upper mountain forest zone. Significant connections between the time of cone infestation byK. strobi and its parasitoids and characteristic phenophases in spruce foliage and cone development, and also the development of selected vegetation of the forest floor at different heights above sea level were determined. It was shown that the population dynamics ofK. strobi had tendency to alternate the increase and decrease in numbers every two years. It was also discovered that every two years spruce cones were inhabited by the population ofK. strobi with increased percentage of individuals having prolonged diapause. In total, the parasitoids reduced the population ofK. strobi by about 16–22.63%. Parasitism ofK. strobi in the lower mountain forest zone was higher than in the upper zone.Triplatygaster contorticornis Ratz. (Hymenoptera: Platygasteridae),Torymus azureus Boheman (Hymenoptera: Torymidae) andTetrastichus strobilanae Ratz. (Hymenoptera: Eulophidae) were most effiecient in reduction of the population ofK. strobi, and in the lower mountain forest zoneT. azureus was the dominant parasitoid species, while in the upper zoneT. contorticornis andT. strobilanae. It was shown that a considerable part of the populations ofT. azureus, T. contorticornis andT. strobilanae have their diapause prolonged and highly synchronized with the diapause of their host.     

竹螟种群动态与预测预报技术

通过对竹螟成虫灯诱结果的统计分析,竹螟的诱蛾量2011年比2010年增长了76%,其中竹织叶野螟Algedonia coclesalis Walker的增长更是达到了233.5%,成虫数占其总诱蛾量的78%。表明竹螟虫口增长趋势明显,而竹织叶野螟的增长趋势更为显著,仍为优势虫种;竹织叶野螟越冬代成虫羽化高峰期在5月18日—6月8日,其诱蛾量占总诱蛾量的84.32%;根据竹螟成虫诱蛾量预测幼虫的发生量与实际调查幼虫发生量相比较,准确率可达到93.7%。     

农林复合生态系统游猎型蜘蛛种群动态及影响因素的研究

蜘蛛是华北农区的主要天敌种群之一,本文研究了农田蜘蛛种群结构及优势种在林带-田埂-农田环境的分布动态。结果表明:(1)研究地区游猎型蜘蛛的优势种为中华狼蛛(Lycosa sinensis Schenkel)和中华平腹蛛(Gnaphosa sinensis Simon);(2)林带和田埂在农作物栽种前和成熟后是蜘蛛栖息和获取食物的主要场所,是农林复合系统中蜘蛛种群的重要种库;(3)耕作活动对蜘蛛种群有较强的负面影响,林带环境具有维持蜘蛛种群稳定性的作用;(4)蜘蛛密度与距林带距离呈负相关性,且在距林带一定范围内密度变化极其显著(P=0.001,α=0.05),表现出明显的林带效应。     

Seasonal population dynamics of Typhlodromus pyri Scheuten (Acari, Phytoseiidae) in apple orchards in the region Meckenheim

Typhlodromus pyri Scheuten (Acari, Phytoseiidae) has been reported as the most important predator of the European red mite, Panonychus ulmi (Koch) (Acari, Tetranychidae) in apple culture. However, biological data on T. pyri was insufficient on important parameters like seasonal population dynamics and within-tree and on-leaf distribution in apple orchards in the region of Meckenheim, Germany. The purpose of the present work was, therefore, to obtain experimental data on these parameters of T. pyri from 2000 to 2002 in the apple orchards in this region. The results showed that overwintered females of T. pyri reactivate and start laying eggs between late March and early April. The mean daily number of the different stages of T. pyri per leaf peaked in July each year, where it ranged between 0.92–1.68 eggs, 0.81–1.41 nymphs, 0.64–1.32 females and 0.37–0.52 males. A significantly higher number of T. pyri individuals congregated in the bottom layer of trees (0.34–0.64 individuals/leaf) than in the middle and top layers (0.23–0.38 and 0.12–0.23 individuals/leaf, respectively). We found that 91.4–94.1% of the total eggs, 89.6–91.7% larvae, 73.0–76.5% nymphs, 60.5–64.6% adult females and 52.6–55.9% adult males concentrated their activities in the inner area of the leaf surface. More than 50% of the predatory mites congregated in the bottom layer in winter. Mean total density of the overwintering females in December of 2000,2001 and 2002 ranged between 10.6–14.2 females/5 cm twig in the bottom, 7.3–10.4 in the middle and 4.1–6.9 in the top layers of the apple trees. Mean total fecundity recorded over the 3 years was lowest in the overwintering generation with 31.8–37.6 eggs/female, highest in the June generation with 45.9–53.7 eggs/female, and intermediate in the August generation with 41.5–46.1 eggs/female. The overwintering generation was composed entirely of females, while the female to male ratio in the June generation was 2:1, and in the August generation 3:1. T. pyri overwinters as adult females in rough structures, cracks and crevices of twigs.     

肥须亚麻蝇和巨尾阿丽蝇的营养价值

肥须亚麻蝇(PC)和巨尾阿丽蝇(AG)幼虫的干物质中蛋白质含量高于60%,成虫干物质中蛋白质含量高于70%。幼虫、成虫必需氨基酸总的含量[g·(100g)-1蛋白质]在46~59之间,均高于FAO/WHO的标准模式35;幼虫、成虫必需氨基酸与氨基酸总量的比值均大于40%的标准模式。在必需氨基酸中,除缬氨酸、蛋氨酸 胱氨酸含量低于优质蛋白模式外,其余均高于标准模式。幼虫的脂肪含量为20%左右,成虫的脂肪含量不到10%,成虫、幼虫不饱和脂肪酸含量均达脂肪酸总量的70%以上。必需脂肪酸均为亚油酸,幼虫亚油酸含量高于40%,成虫亚油酸含量仅为17%左右。PC和AG幼虫中Fe、Zn的含量分别是Fe684、664μg·g-1,Zn170·5、158·0μg·g-1。幼虫Ca含量相当于优质大豆,分别为0·46%、0·48%;P含量高于一般奶粉,分别为0·57%、0·54%。PC、AG幼虫的Ca、P比值分别为0·81、0·89,均高于0·5的理想值。     

Population dynamics,phenology, and overwintering of <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis> (Diptera: Tephritidae) in Hubei Province,China

Since 2004 the oriental fruit fly, Bactrocera dorsalis (Hendel) has become widespread and economically important in Wuhan, Hubei Province, central China. In this article, the population dynamics of B. dorsalis were monitored using methyl eugenol-baited traps during 2008–2009 in Wuhan. Adults were captured from early July to the end of December in a citrus orchard and peaked in October and early November. Adult population peak coincided with the ripeness period of sweet oranges in October. Infestation with B. dorsalis was more serious in 2009 than in 2008. Field surveys of host plants for this fly species combined with rearing experiments indicated that pear was the first host plant infested by B. dorsalis. We recorded the following host shift pattern: pear (Pyrus communis L.), jujube (Zizyphus jujuba L.), persimmon (Diospyros kaki L.), and sweet orange (Citrus unshiu Marcor). Our findings suggest that B. dorsalis completes four to five generations per year in this area and most serious damage occurred in the 4th generation in the citrus orchards. The availability of preferred host fruits and the low winter temperature are key factors influencing population fluctuations. Overwintering potential experiments of adults, larvae, and pupae were also carried out in the field. Results suggest that a small proportion of pupae were able to survive winter in Wuhan and emerged successfully the following year. Practical and theoretical implications of the results regarding the invasion potential and management strategy of B. dorsalis in Hubei Province are discussed.     

中国蝇科秽蝇属分布(双翅目:蝇科)

秽蝇属隶属于双翅目环裂亚目蝇科秽蝇亚科秽蝇族,是秽蝇族中最大的一属。文中报告了近年来作者对我国秽蝇属的分类研究结果。通过调查研究及查阅文献资料,发现我国该属目前共有92种（亚种）,包括1新种,高颊秽蝇（另文发表）,4项新组合,即褐翅秽蝇,黄足秽蝇,乳翅秽蝇和叉尾秽蝇。记录了中国产该属92种（亚种）并介绍了其地理分布。     

Predatory phytoseiid mites (Acari: Mesostigmata) in vineyards and fruit orchards in Southern Tyrol

Results of monitoring communities of the predatory phytoseiid mites in 70 commercial vineyards and 29 apple orchards in the Eisack-and Etsch-river valleys, Southern Tyrol, are reported and discussed.Typhlodromus pyri Scheuten,Amblyseius andersoni (Chant) and, locally,A. finlandicus Oudemans were the most abundant species.     

Toxicity and repellence of Taiwanese indigenous djulis, Chenopodium formosaneum, against Aedes albopictus (Diptera: Culicidae) and Forcipomyia taiwana (Diptera: Ceratopogonidae)

The biological activity of djulis (Chenopodium formosaneum) extracts was evaluated against mosquitoes and biting midges. Djulis extracts were relatively nontoxic to Aedes albopictus larvae. However, they showed interesting repellence against adult mosquitoes as estimated by the median effective dosages (ED₅₀). ED₅₀ values for djulis extracts against mosquito adults in descending order were: seed extracted with methanol (0.83 %), seed extracted with dichloromethane (0.66 %), leaf extracted with methanol (0.50 %), and leaf extracted with dichloromethane (0.40 %). Field tests also suggested that djulis methanol extracts were effective at about a 1 % level against biting midges (Forcipomyia taiwana). A total of 15 and 20 compounds accounting for 88.8 and 79.9 % in the seed and leaf extract, respectively were identified by gas chromatography coupled to mass spectrometry (GC–MS). Among these, 9, 12-octadecadienoyl chloride, (Z, Z) was found in both as well as being the major constituent in the leaf extract (35.7 %). Further studies on the repellent property of the extracts against mosquitoes and biting midges are warranted.     

Biology,incidence and host susceptibility of Pineus boerneri (Hemiptera: Adelgidae) in Colombian pine plantations

Adelgids (Hemiptera) in the genus Pineus have been reported as introduced insect pests causing serious losses to Pinus plantations worldwide. In 2008, Pineus boerneri was recorded for the first time in Colombia, with infestations noted on Pinus kesiya, P. tecunumanii, P. maximinoi and P. oocarpa. The lack of information on this insect in Colombia prompted investigations of its life cycle and infestation levels as well as host susceptibility of the main Pinus species planted in Colombia. In addition, the possibility of using a Ceraeochrysa species, an already established predator of adelgids in Colombia, for biological control was considered. Results showed that Pineus boerneri in Colombia has an anholocyclic life cycle comprised of four instars with a complete duration of between 49 and 97 d. Infestations were higher in the middle and upper part of trees. Pinus kesiya and P. maximinoi had the highest levels of susceptibility in field as well as in greenhouse trials. A survey of naturally infested trees showed P. tecunumanii to be moderately susceptible, whereas P. patula and P. oocarpa had low levels of susceptibility in a greenhouse trial but were not susceptible in the field. Investigations considering the impact of predation of Ceraeochrysa species showed a high predation rate of up to 140 P. boerneri consumed per day by a single Ceraeochrysa individual. Other predators of P. boerneri were recorded but were not sufficiently common to warrant detailed study.     

Application of some bacterial varieties ofBacillus thuringiensis and its bioproduct Delfin onSynanthedon myopaeformis Borkh. (Lep. Aegeriidae) in apple orchards

Field experiments were conducted using the biological agentBacillus thuringiensis to control the clearwing moth,Synanthedon myopaeformis (Lep. Aegeriidae) in apple orchards at Alexandria governorate during 1995, 1996 and 1997. Three bacterial varieties ofB. thuringiensis showed significant influence on the reduction of borer infestation. Four applications with the sporic concentration 12×10⁷ spores/ml of each ofB. th. var.kurstaki, B. th. var.alesti andB. th. var.thuringiensis induced 82.5, 51.1 and 42.1% reduction of infestation, respectively. Methods of application showed highly significant effect on infestation level. Sparying after scraping was the best method (80.0%, reduction) followed by painting after scraping (71.5%, reduction) then spraying alone (59.7%, reduction) or painting alone (43.0%, reduction). A control programme was carried out using three applications of the biomaterial, Delfin at the rate of 200 g/100 I.w. during mid-March, early June and mid-August resulted in 88.5–91.4% reduction of infestation.     

太阳坪村果园病虫害调查与分析

采用普查与定点调查相结合的方法,对太阳坪村果园主要病虫害种类及危害情况进行了系统调查。结果表明,危害太阳坪村水果生产的虫害主要有35种;病害主要有13种。其中危害较严重的病虫害为天牛、食心虫、褐腐病、烟煤病、黑斑病等。并对太阳坪村果园管理经营所存在的问题和防治对策进行了分析。调查结果为进一步制定绿色防控和经营措施,保障太阳坪村果树种植业的持续健康发展具有重要意义。     

沙棘绕实蝇的生物学习性

[目的]沙棘绕实蝇严重危害沙棘果实,使沙棘种植地蒙受巨大经济损失。研究其生物学习性,可以为有效监测和控制沙棘绕实蝇提供理论指导。[方法]通过室内人工饲养和野外观察,研究沙棘绕实蝇的羽化、交尾、产卵、化蛹等生物学习性和野外发生动态。[结果]沙棘绕实蝇成虫在野外从6月中旬至8月上旬均可见到,发生量受天气影响较大;成虫主要集中在6:00—10:00羽化,羽化量占当日羽化量的81.3%,羽化高峰出现在8:00—9:00;化蛹时间主要集中在凌晨0:00—6:00,尤其是3:00—6:00钻出果实化蛹的幼虫数量较多,与其它时间段有明显差异;交尾时间主要集中在白天光照比较强的时间段,一天当中有两次交尾高峰,分别出现在12:00—13:00和16:00—17:00,交尾平均持续时长为239±11.86 min;沙棘绕实蝇产卵期沙棘果长径6.65±0.28 mm,宽径5.47±0.40 mm,一果只产一卵。[结论]沙棘绕实蝇在内蒙古磴口地区一年发生一代,幼虫钻蛀果实,蛹隐藏在地下,成虫期较短,防治工作应集中在成虫期进行。     

Individual vulnerability factors of Silver fir (Abies alba Mill.) to parasitism by two contrasting biotic agents: mistletoe (Viscum album L. ssp. abietis) and bark beetles (Coleoptera: Curculionidae: Scolytinae) during a decline process

? Context

In recent decades, there have been increasing reports of forest decline, especially in Mediterranean forest ecosystems. Decline in tree vitality is usually due to complex interactions between abiotic factors and biotic agents that attack weakened trees.

? Aims and methods

Estimating dendrometrical characteristics [basal area increment (BAI), age at DBH from tree ring counting, social status, height, and diameter], tree health status, and a competition index, we investigated the individual vulnerability of a French declining silver fir forest to both mistletoe (Viscum album L. ssp. abietis) and bark beetles (Pityophthorus pityographus Ratz., Pityokteines vorontzovi Jac., and Pityokteines spinidens Reitt.).

? Results

BAI was negatively correlated with both mistletoe infection (via mistletoe biomass) and bark beetle attack (number of insects per square meter), but there was evidence of divergence in tree choice between two groups of parasites. Mistletoe preferentially infected isolated and dominant trees that showed higher past growth rates than non-infected ones. Conversely, bark beetles mainly attacked defoliated and preferably declining trees with diameter (DBH) lower than 44.5 cm and slower past growth.

? Conclusion

While successive severe drought periods are thought to greatly weaken southern silver fir populations, mistletoe and bark beetles may contribute actively to their decline processes as inciting and contributing factors, respectively.     

Winter mortality in sub-corticolous populations of Ips typographus (Coleoptera, Scolytidae) and its parasitoids in the south-eastern Alps

A study concerning the winter mortality of a sub-corticolous population of Ips typographus and its parasitoids has been carried out in the south-eastern Alps (Italy) during the winter 1997/98. Three attacked spruce trees were sampled three times (November, February and April) by collecting infested bark disks (1?dm² each). All insects that emerged from the bark or died in the samples before emergence were counted. The mean number of living Ips typographus occurring under the bark decreases by 49?% from November to April. Winter mortality mainly affects larval stages and young adults. The same trend was observed for the parasitoids Coeloides bostrychorum (48.5?%) and Roptrocerus xylophagorum (47.5?%).