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桐花树毛颚小卷蛾Lasiognatha cellifera Meyrick是广西北部湾桐花树的主要害虫,通过室内饲养和林间观察研究,对桐花树毛颚小卷蛾各虫态的形态特征进行了描述,基本了解其生活习性及生活史。该虫在广西北部湾地区1a发生12代,世代重叠。以2~3龄幼虫在桐花树叶片上卷叶越冬,3月上旬开始羽化为成虫,1~2d后即交配产卵,平均每雌产卵量76粒。卵历期2~4d,幼虫历期11~15d,蛹历期7~8d,成虫寿命约6d;该虫有2个明显的危害高峰期,分别出现在春季和秋季。提出桐花树毛颚小卷蛾的初步防治建议。 相似文献
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毛颚小卷蛾幼虫空间分布型的研究 总被引:2,自引:0,他引:2
毛颚小卷蛾幼虫是红树林的灾害性害虫之一,主要危害桐花树(Aegiceras corniculata)。主要应用扩散系数(C)、平均拥挤度(m*)等6种指标研究该虫的空间分布情况。结果表明:毛颚小卷蛾幼虫呈现聚集分布,分布的基本成分是个体群,聚集强度随种群密度的升高而相应增大;钦州康熙岭滩涂外滩植株有虫株率较低(10%以下),中滩25%左右,内滩最高(100%),而北海丹兜和防城港北仑河附近的红树林滩涂,从外滩到内滩有虫株率呈现逐渐降低的趋势;幼虫在10月上旬危害最为严重。 相似文献
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通过5种聚集度指标以及Iwao法的m~*-m直线回归法和Taylor法的幂法则,对桐花树人工种植区内毛颚小卷蛾幼虫空间分布格局进行分析。结果表明:毛颚小卷蛾幼虫1年中在林间总体上呈聚集分布,仅在7月中下旬和10月中下旬呈均匀分布。Iwao的m~*-m回归方程为m~*=1.069 m+1.911,显示该虫在林间呈聚集分布,分布的基本成分是个体群,个体之间存在相互吸引关系。样本平均数(m)与方差(S~2)的对数值的关系式为lgS~2=1.339lgm+0.216,显示该虫在林间呈聚集型分布,且分布具有密度依赖性,即聚集强度随种群密度的升高而相应增大。Iwao的理论抽样数公式为N=t~2(2.911/m+0.069)/D~2。 相似文献
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在广东梅州实验地全光照条件下用恒定淹水位淡水培养处理红树植物桐花树幼苗1年,以人工海水(盐度8 g·kg-1)为对照,研究了淡水培养对桐花树幼苗生长发育的影响。结果表明:淡水组幼苗的茎高、基径、胚轴直径等指标显著低于人工海水组,而叶片数则极显著低于人工海水组,在胚轴高、分枝数、叶长、叶宽、叶长/叶宽、根长、根径、根数等指标上差异不显著;淡水组的叶面积比人工海水组大18.11%,差异显著。180天时,淡水组植株的根、茎、叶的生物量及总生物量与人工海水组的相比没有显著差异,但分别比人工海水组低12.50%、18.40%、16.48%、16.32%,两组植株的根、茎、叶生物量的大小均为:茎>叶>根;360天时,2组植株的根、茎、叶的生物量及总生物量间差异不显著,但淡水组比人工海水组分别低33.88%、17.48%、28.30%、26.51%,两组植株的根、茎、叶生物量的大小均为:叶>茎>根。种植1年后,两组桐花树幼苗的存活率都达90%以上,部分植株有花蕾出现且开花,其中,人工海水组植株先出现花蕾,而淡水组植株相对迟25 天出现花蕾,但淡水组出现花蕾的株数比人工海水组多33.82%。由此可见,淡水对桐花树幼苗大部分形态指标均有显著影响,但桐花树幼苗可以正常生长,且能够开花,表明桐花树对淡水环境具有较强的适应性。 相似文献
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粤港地区红树林害虫种类调查 总被引:4,自引:0,他引:4
从广东省及香港特区红树林采集到害虫种类26种,其中15种为首次报道的危害红树林的害虫,广州小斑螟、柑橘长卷蛾、桐花毛颚小卷蛾、荔枝异形小卷蛾和白缘蛀果斑螟5种害虫对白骨壤、桐花树和木榄造成严重危害。此外,对主要害虫林间发生规律进行了研究。 相似文献
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广东木榄+桐花树群落上的白缘蛀果斑螟和荔枝异形小卷蛾研究 总被引:2,自引:0,他引:2
白缘蛀果斑螟和荔枝异形小卷蛾是红树林木榄+桐花树群落上的重要害虫,在广东省局部区域的红树林保护区,已经对木榄造成严重危害。白缘蛀果斑螟1年完成4代,第1至第3代虫历时48~66d,越冬代历时180d;荔枝异形小卷蛾1年完成5代,第1至第4代虫历时39~44d,越冬代历时188d。白缘蛀果斑螟和荔枝异形小卷蛾幼虫均危害木榄的花萼和胚轴,荔枝异形小卷蛾能够迁移到桐花树上危害桐花果实。在木榄+桐花树群落上,白缘蛀果斑螟成虫占54%,荔枝异形小卷蛾成虫占46%。林间世代重叠,以幼虫和蛹越冬。在4月下旬~5月中旬,受害花萼和受害胚轴数量有一个高峰期,而7月上旬-10月中旬,则有一个明显的低值期。白缘蛀果斑螟和荔枝异形小卷蛾种群数量消长规律与受害花萼和受害胚轴的数量变化规律成正相关,前者同样也出现一个高峰期和一个低值期。白缘蛀果斑螟和荔枝异形小卷蛾与捕食性蜘蛛数量的比例为1:0.30,捕食性蜘蛛的捕食作用不明显。 相似文献
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红树林丽绿刺蛾的抗逆性研究 总被引:9,自引:0,他引:9
红树林是自然分布于热带和亚热带海岸潮间带的木本植物群落 ,具有造陆、护岸、护堤等功能 ,是维持海岸生态平衡的重要生态系统。由于人为破坏和干扰 ,使红树林的植物种类由多变少 ,由高大乔木变为矮小灌丛 ,湿地生态系统功能日益衰退 ,遭受各种有害昆虫的危害 ,严重影响其生长 ,极大限制红树林各种功能的发挥。国外主要有澳大利亚、泰国、印尼、新加坡及香港等国家和地区先后报道白骨壤(Avicenniagerminans)、海漆 (Excoecariaagallicha)和桐花树 (Aegicerascorniculatum)叶片遭到鳞翅目(Lepidoptera)昆虫为害 ;古巴大量的大红树苗木受蛀干害虫为害 (Westetal.,1 985 ;Whittenetal.,1 986)。国内仅林鹏 ( 1 985 ;1 993;1 997)、汪维礼 ( 1 988)等报道了福建、浙江秋茄 (Kandeliacandel)被藤壶 (Balanussp .)、卷叶蛾 (Tortricidae)和茎腐病危害 ,并提出红树林病虫害防治是营造红树林实践应该引起重视的问题。丽绿刺蛾 (Latoialepida)是红树林主要食叶害虫之一... 相似文献
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Marcus Hardie Nawari Akhmad Caroline Mohammed Daniel Mendham Ross Corkrey Abdul Gafur 《Southern Forests》2018,80(1):37-50
In Indonesia, Acacia mangium plantations exceed 1.6 Mha contributing approximately 3.5% of the country’s GDP. The viability of these plantations is increasingly threatened by fungal pathogens, insect pests, squirrels, monkeys, elephants and wind damage. Studies indicate that the problem is growing and in some areas, fungal pathogens such as Ganoderma and Ceratocystis species have contributed up to 50% tree mortality by the fourth rotation. Multiple statistical procedures were employed to examine the influence of soil and topographical properties on tree survival (trees ha?1), wood production (m3 ha?1), and mortality associated with Ganoderma root rot, Ceratocystis wilt and by wind. Soil family level was found to be a good indicator of tree mortality. Plots with fine-loamy Typic Kandiudult soils had the highest tree survival and mortality associated with species of Ganoderma and Ceratocystis, but had the lowest incidence of mortality by wind. The degree of association between soil and topographic variables with tree survival, wood production and the cause of mortality were poor and inconsistent. Tree survival was slightly higher on upslope areas away from valley bottoms, and drier mid-slopes, ridges and hilltops, and very low pH (<3.3) soils. Wood production was also slightly higher in drier, elevated locations, away from valley bottoms. Mortality by wind was slightly higher in moist, poorly drained, low-lying valley bottoms and topographically flat areas. Our ability to further pinpoint the influence of topography and soil attributes on wood production and cause of mortality was greatly compromised by the lack of site-specific soil data, and potential misclassification of the cause of mortality. This study could not reliably or consistently relate tree survival, wood production or the cause of mortality to any one, or combination of, soil and topographic variables. 相似文献
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Determinants of mortality in a mixed broad-leaved Korean pine forest in northeastern China 总被引:1,自引:1,他引:0
Chunyu Fan Lingzhao Tan Peng Zhang Jingjing Liang Chunyu Zhang Juan Wang Xiuhai Zhao Klaus von Gadow 《European Journal of Forest Research》2017,136(3):457-469
Empirical analyses of forest dynamics are important for understanding various ecological processes underlying particular forest communities, among which tree mortality is considered a key process driven by many local factors. To evaluate the effects of tree size, as well as biotic and abiotic factors on tree mortality, we compared species-specific mortality rates in a 21-ha temperate multi-species natural forest in northeastern China, where all trees had been mapped. Our study shows that the mortality rates are highly variable among the different tree species and the influence of habitat preference on the mortality rate of a species across habitats was insignificant. Using generalized linear mixed-effects models, we further found that among the drivers of tree survival, tree size had the strongest effect across different species. There are significant negative relationships between the basal area of conspecific neighbors and tree survival at the community level across almost all the guilds. Regarding abiotic factors, elevation had a greater effect on tree survival than other topographic variables did. Abiotic factors affected shrubs more than tall canopy species in terms of survival rate. Our study suggests that tree size, density-dependent effects and niche partitioning contribute to the regulation of survival pattern of temperate forest communities, but the relative importance of these factors varies greatly among guilds and species. This study has shown that it is essential to consider the relative importance of both, intrinsic (tree size) and extrinsic (biotic and abiotic) factors in analyzing tree mortality. 相似文献
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为探索竹复合管材耐海水腐蚀性能,开展了人工模拟海水不同浸泡时间的试验,研究其物理力学性能及微观结构的变化。结果表明:竹复合管材的质量和厚度均随浸泡时间的增加而增大,当浸泡30 d后,其质量仍持续增加,而厚度膨胀率趋于稳定;竹复合管材的硬度、弯曲强度和弯曲弹性模量均随浸泡时间的增加呈现先降低后增加的趋势,当浸泡30 d后,分别增加3.36%、8.44%和12.37%;显微结构显示,当浸泡30 d后,竹复合管材表面无龟裂、裂纹,结构层树脂胶黏剂与竹纤维胶结、填料和网格布胶结界面没有脱粘现象,耐腐蚀性能评价为耐腐等级。 相似文献