我国梢斑螟属害虫经济重要性分析

以梢斑螟属Dioryctria害虫的自然属性为主,构建我国梢斑螟属害虫经济重要性分析指标体系,明确各项指标间的叠加关系,确定每项指标的赋分标准.结果表明:微红梢斑螟Dioryctria ru-bella Hampson、果梢斑螟D.pryeri Ragonot、冷杉梢斑螟D.abietella Denis et Sch...     

南京地区微红梢斑螟对松林的危害调查

微红梢斑螟是南京地区重要的松树蛀梢害虫,尤其对人工火炬松幼林危害严重.对南京及周边4个不同立地条件和林型的野外试验地松林受害株率进行了调查,统计结果表明:微红梢斑螟对人工纯林危害大于天然更新林;对火炬松危害大于马尾松和黑松;此外,统计分析表明马尾松受害梢率与受害株胸径呈典型的负线性相关关系.对采集回的受害松枝室内剖查结果统计显示,火炬松受害大于马尾松、黑松和湿地松.     

微红梢斑螟对国外松的危害及防治研究

微红梢斑螟对国外松的危害比较普遍,据在湖南52块标准地调查,占被调查块数的71.15％;被害株率为10.13％。其中最严重1块为3年生火炬松幼林,被害株率达87.5％;单株受害梢严重的达28个枝条之多、主要是主梢和上部1—2轮生侧梢。此虫在湖南一年发生二代,生活史极不整齐,以幼虫在被害处越冬。化学和生物林间防治试验证明,多种化学药剂防治均有一定效果,而生物防治则以白僵菌防效明显。化防林间喷雾以2.5％溴氰菊酯2000倍液最好,防效可达53.97—64.81％;生防林间措施以含孢量65/克白僵菌,每亩1公斤,死虫率达73.91％。     

微红梢斑螟危害枝梢的空间分布型及抽样技术研究初报

本文采用2种回归分析法和6种聚集指标，对微红梢斑螟危害梢在马尾松林中的分布进行了研究。结果为聚集分布，在此基础上，利用Iwao的方法进行了序贯抽样。     

微红梢斑螟的危害及防治

微红梢斑螟（Dioryctria rubella）原名松梢螟，危害多种松树，在我县危害火炬松、湿地松幼林，以幼虫取食当年新梢造成危害。上世纪中后期随着我县造林工作不断深入，外松林面积增幅较大，一度出现微红梢斑螟大面积危害的情况，严重影响了外松的正常生长，现将我们在实践中探索出综合防治措施总结如下。     

红松的化学防御及冷杉梢斑螟和赤松梢斑螟的生存策略

为了探讨冷杉梢斑螟和赤松梢斑螟幼虫的生存策略差异及与寄主红松化学防御的相互关系,研究1,3,5龄冷杉梢斑螟、赤松梢斑螟幼虫中肠解毒酶、保护酶的活性,同时分析相应生长发育期红松健康、受害球果及主梢内多种防御酶的活性。结果表明:健康红松球果及主梢中多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性变化与其生长发育时期有关。梢斑螟幼虫的取食可诱导红松球果及主梢内5种防御酶活性显著提高,寄主不同部位防御酶的活性变化与该龄期幼虫取食有关。不同生存策略的2种梢斑螟幼虫体内解毒酶、保护酶活性有差异。冷杉梢斑螟幼虫专食红松球果,其体内谷胱甘肽S-转移酶(GST)、羧酸酯酶(CarE)、多功能氧化酶(MFO)显著高于果梢间转移为害的赤松梢斑螟。超氧化物歧化酶(SOD)和几丁质酶(CT)的活性与梢斑螟幼虫是否转移为害无相关性。赤松梢斑螟幼虫体内酚氧化酶(PO)和过氧化物酶(POD)活性高于冷杉梢斑螟,表明这2种活性较高的保护酶,能够降低其在转移为害过程中面临的死亡威胁。冷杉梢斑螟幼虫主要通过生理解毒,而赤松梢斑螟则以生理解毒和改变取食范围相结合的方式,适应寄主植物的化学防御。植物化学在2种害虫的生存演化中起着重要作用。     

云杉梢斑螟发生与云杉林分结构关系的研究

云杉梢斑螟是云杉林最主要的害虫之一,文章对肃南裕固族自治县云杉梢斑螟的发生与林分结构的关系进行了调查。结果显示,林分的郁闭度越低,云杉梢斑螟的虫口密度和有虫枝率越高,其危害越严重,中龄林平均虫口密度最大,纯林中云杉梢斑螟发生比混交林发生严重。     

微红梢斑螟生物学特性及防治技术

微红梢斑暝,又名松梢暝,主要危害马尾松、国外松,以及油松、黑松、黄山松、雪松等。2006年旌德县暴发该虫危害,全县1.75万亩幼松林都不同程度地发生,3年生马尾松小班受害严重,虫株率达90%以上。幼虫蛀害主梢,引起侧梢丛生,使树冠形成畸形成为扫帚状,树木不能成材,或降低木材利用价值。幼虫蛀食球果影响种子产量,蛀食幼树枝干,则造成幼树死亡。     

日本龟蜡蚧寄主植物种类及危害程度调查

2013—2014年,采用踏查结合抽样调查的方法对遵义市日本龟蜡蚧的寄主植物种类及危害程度进行了调查。结果表明:日本龟蜡蚧寄主植物有36科71种(变种),其中三峡槭、乌柿等27种(变种)为国内首次报道。发生普遍且严重的寄主植物有二球悬铃木、三球悬铃木、加杨、天竺桂、广玉兰、枇杷、八角金盘、杜英、海桐、白兰。日本龟蜡蚧在遵义市不同生境中,以市区主干道和住宅小区的园林植物受害最为严重。     

影响松果梢斑螟寄主选择的植物挥发物成分研究

在松果梢斑螟幼虫转移危害期和成虫产卵选择期,采用XAD2的吸附法和二氯甲烷提取法以及GC-MS分析,研究了虫害诱导后油松和华山松球果或针叶挥发性萜类成分.结果表明:幼虫转移危害期,油松球果虫害后的特异性组分为α-蒎烯、β-非兰烯、β-蒎烯、β-香叶烯、D-柠檬烯、异松油烯、乙酸天竺葵酯,以及大香叶烯-D和石竹烯等9种;球果受害后,倍半萜含量显著下降;但非寄主华山松健康球果和虫害果挥发性萜类主要组分有8种,其组成和含量与油松球果显著不同.成虫产卵选择期,油松健康果和虫害果挥发性萜类成分和含量有很大差异,其中特异性组分是α-蒎烯、β-非兰烯/4-侧柏烯、β-香叶烯、D-柠檬烯,以及未知成分、石竹烯和α-石竹烯等8种;与健康果和虫害果相比,针叶挥发性萜类的特异成分为α-蒎烯、乙酸龙脑酯、莰烯、β-蒎烯、对-薄荷-1(7),3-二烯,以及未知成分、石竹烯和α-石竹烯等8种.幼虫选择和趋向试验表明:幼虫明显趋向和选择油松球果而不选择华山松球果;在油松球果及其提取液试验中,幼虫明显趋向和选择虫害球果.     

不同植物、同种植物不同组织部位中白藜芦醇含量变化研究

白藜芦醇已被列为抗心血管病，抗癌最有前途的药物之一。本研究用高效液相色谱法测定虎杖、辣蓼、显齿蛇葡萄、葡萄、何首乌5种植物中的白藜芦醇的含量。结果表明：这5种植物中以虎杖根中白藜芦醇含量最高，同种植物不同组织部位中白藜芦醇含量差异较大。     

深圳市植物物种指数与本地植物指数分析

以文献调研为主,结合野外踏查,对深圳市野生植物和常见栽培植物、建成区内本地植物和外来植物进行了统计分析,得出深圳市"植物物种指数"为0.789,"本地植物指数"为0.701;还分析了深圳植物的区系特点和外来植物的应用现状。       

北京八达岭植物群落多样性特征分析

根据34个样地的调查资料,分析了该地区森林植物群落物种多样性的特征:群落内各层物种丰富度指数的大小为草本层>灌木层>乔木层;多样性指数的大小为乔木层<灌木层和草本层。灌木层与草本层的多样性指数随林分郁闭度变化而变化,在林分郁闭度为25%的侧柏黄栌混交林中,灌木层的多样性指数和丰富度指数小于草本层;在郁闭度53%的杂木林中,灌木层和草本层的多样性指数接近;在郁闭度53%以上的各个群落内,草本层的多样性指数和丰富度指数基本上都大于灌木层。人工林中的物种多样性变化多样,明显低于天然林,林分层次单一,更新不良,缺乏灌木层和地被植物,生态系统很不稳定。     

Cellulase in <Emphasis Type="Italic">Anoplophora glabripennis</Emphasis> adults fed on original host tree species and non-original host trees

Cellulase activities of Anoplophora glabripennis (Motsch.) adults from two host plants (Populus simonii × P.pyramidliscr cv.Opera Hsu.and Salix matsudana Koidz) fed on three different host tree species (Acer negundo Linn.,S.matsudana Koidz and P.simonii × P.pyramidliscr cv.Opera Hsu.) were investigated.Enzyme activities of endoglucanase and β-glucosidase in the intestines of the insects were measured.The results show that there are no statistically significant differences in the enzyme activities of endoglu...     

Influence of host plant species on the development and reproduction of hawthorn spider mites

A leaf disc bioassay was employed to investigate the influence of host species of deciduous fruit trees, like apple, peach, plum, cherry and apricot, on the development and reproduction of the hawthorn spider mite Tetranychus viennensis Zacher in the laboratory under conditions of 25±1°C, 60±10% RH and a photoperiod of 16 h: 8 h light: dark. This was done by determining the duration of each life stage of the mites, the intrinsic rate of population increase (r _m ), mean generation time (T) and net reproductive rate (R ₀) of the spider mites on each of the host plant species. Differences in life table parameters of the spider mite among host plants were analyzed with the jack-knife method. The results indicated that plum might be the best suitable plant for the spider mite among the plants tested due to shorter developmental period and higher intrinsic rate of increase, whereas cherry and apricot were least suitable due to their long developmental duration and low intrinsic rates of increase. When the spider mites were transferred from apple to other fruit trees, negative effects on developmental duration, fecundity and life table parameters were found in the first generation, but the effects faded out in succeeding generations. When transferred onto plum and peach, the spider mite adapted to the new hosts in the second generation; however, on cherry and apricot, it adapted in the third generation. __________ Translated from Acta Ecologica Sinica, 2005, 27(7) [译自: 生态学报, 2005, 27(7)]     

The role of disturbance severity and canopy closure on standing crop of understory plant species in ponderosa pine stands in northern Arizona,USA

Concerns about the long-term sustainability of overstocked dry conifer forests in western North America have provided impetus for treatments designed to enhance their productivity and native biodiversity. Dense forests are increasingly prone to large stand-replacing fires; yet, thinning and burning treatments, especially combined with other disturbances such as drought and grazing, may enhance populations of colonizing species, including a number of non-native species. Our study quantifies plant standing crop of major herbaceous species across contrasting stand structural types representing a range in disturbance severity in northern Arizona. The least disturbed unmanaged ponderosa pine stands had no non-native species, while non-native grasses constituted 7–11% of the understory plant standing crop in thinned and burned stands. Severely disturbed wildfire stands had a higher proportion of colonizing native species as well as non-native species than other structural types, and areas protected from grazing produced greater standing crop of native forbs compared to grazed unmanaged stands. Standing crop of understory plants in low basal area thinned and burned plots was similar to levels on wildfire plots, but was comprised of fewer non-native graminoids and native colonizing plants. Our results also indicate that size of canopy openings had a stronger influence on standing crop in low basal area plots, whereas tree density more strongly constrained understory plant standing crop in dense stands. These results imply that treatments resulting in clumped tree distribution and basal areas <10 m² ha⁻¹ will be more successful in restoring native understory plant biomass in dense stands. Multiple types and severity of disturbances, such as thinning, burning, grazing, and drought over short periods of time can create greater abundance of colonizing species. Spreading thinning and burning treatments over time may reduce the potential for non-native species colonization compared to immediately burning thinned stands.     

Cellulase in <Emphasis Type="Italic">Anoplophora glabripennis</Emphasis> adults emerging from different host tree species

In order to investigate different kinds of cellulase in insect pests, we selected male and female adults of Anoplophora glabripennis （Motschulsky） emerging from four different host species （Populus alba var. pyramidalis, P. nigra var. thevestina （Dode） Bean., P. simonii × P. pyramidliscr cv. Opera 8277 Hsu. and Salix matsudana f. lobato-glandulosa） as our research material. The enzyme activitives of three kinds of cellulase in the intestines of the adult insects were measured. The Cx-cellulase isozymes were detected with a CMC-incorporated polyacrylamide gel. The results show that： there are no statistically significant differences between the enzyme activities of males and females emerging from the different host species. The order of magnitude in activity is： Cx-cellulase 〉 β-glycosidase 〉 C1-cellulase. When the adults emerge from the same host species, there are no statistically significant differences between male and female enzyme activities of β-glycosidase and C1-cellulase, but the enzyme activity of Cx-cellulase of males is clearly higher than that of females. The patterns and migration of Cx-cellulase isozymes of males and females emerging from differ-ent hosts trees are clearly not different, and neither are they different when emerging from the same hosts.     

秦岭植被景观多样性与物种梯度分析

秦岭植被景观类型丰富,具有过渡性和复杂性特点,植被垂直分带明显,在分析秦岭植被景观空间分布格局的基础上,利用植被景观多样性指数,分析了秦岭山地植被景观的数量统计特征与海拔的变化关系;利用基于GIS的梯度分析方法,分析了秦岭的植被与海拔梯度的关系,得到秦岭不同植被景观类型的斑块数、分布范围、植被分布的高度均值和标准差,并以太白山为例,对太白山植物种进行了梯度分析。结果表明:秦岭各植被型的多样性指数Simpson指数D、Shannon-wiener指数H′和均匀度指数基本上呈相同的变化趋势,随着海拔的增加,呈波浪式的变化趋势,自然植被在海拔1 325 m、1 500 m和2 930 m时出现峰值。乔木的多样性指数在海拔1 500 m和2 930 m时达到最大值,在海拔1 200~1 470 m和1 600~2 650 m左右处,乔木的多样性指数值较小,但均匀度指数却较高;灌木的多样性指数在海拔1 325 m时达到最大值;草本的多样性指数呈波浪式上升的趋势,海拔2 400 m和3 500 m左右处有2个峰值。随着海拔高度的增加,太白山依次出现温带草丛→温带落叶灌丛→温带落叶阔叶林→亚热带针叶林→亚热带和热带山地针叶林→草甸→高寒草甸等植被类型,并随海拔的升高,依次出现相应的植物种。