【作者】 杨秀好；

【导师】 骆有庆；

【作者基本信息】 北京林业大学 ， 森林保护， 2013， 博士

【摘要】 桃金娘科Myrtaceae桉树Eucalyptus原产于澳洲大陆,是世界上广泛引种栽培的硬木树种。目前,我国桉树引种栽培区域已扩展到华南、西南10省区,总面积约400万hm2,以广西种植面积最大(182万hm2,占全国桉树面积的46%)。随着我国桉树大规模栽培以及经营管理不科学,大量本土昆虫转移危害桉树,造成的损失日趋严重。桉蝙蛾Endoclita signifer Walker是近年来在广西和广东新发现危害桉树最严重的钻蛀性害虫,国内外未见对该虫系统研究的报道。为此,本文从该虫分布与危害、寄主与天敌、生物生态学特性、种群动态等内容进行系统研究,主要结果如下：1.明确了广西桉树主要钻蛀性害虫的分布与危害。已发现桉树钻蛀性害虫3目7科13种,其中危害严重的桉蝙蛾分布于60个县,受害面积3710.16hm2；云斑白条天牛Batocera lineolata Chevrolat分布于8个县,受害面积204.38hm2；咖啡豹蠹蛾Zeuzera coffeae Nietner分布于9个县,受害面积210.99hm2。发现桉树钻蛀性新害虫景洪兴透翅蛾Synanthedon jinghongensis Yang et Wang。2.评估了桉蝙蛾危害桉树造成的生长量和经济损失。轻、中和重度受害林分平均单株材积和生物量损失分别为0.0110m3和6.38kg、0.0126m3和12.28kg、0.0221m3和20.87kg,单位面积材积损失量分别为0.495m3/hm2、1.512m3/hm2(?)(?)4.973m3/hm2,按当前价格计算,材积和材质2项损失合计分别为1253元/hm2、3494元/hm2和8335元/hm2。虫口密度4头/株以上与3头/株以下生长量损失差异显著。3.基本明确了桉蝙蛾的自然寄主和潜在寄主树种。该虫在广西的自然寄主包括21科31属39种,其中桃金娘科、含羞草科Mimosaceae、大戟科Euphorbiaceae、木犀科Oleaceae、马鞭草科Verbenaceae、榆科Ulmaceae和葡萄科Vitaceae植物是其常见寄主植物。尾叶桉Eucalyptus urophylla和巨尾桉E. grandis×E. urophylla、尾巨桉E. urophylla×E. grandis、巨圆桉E. grandis×E. tereticornis3种杂交无性系不同程度受害,巨桉E. grandis、赤桉E. camaldulensis、柳桉E. saligna、蓝桉E. globulus、柠檬桉E. citriodora等品种未发现自然受害。创新了钻蛀性害虫潜在寄主测定方法,共测定14科18属20种植物,其中杉木Cunninghamia lanceolata、台湾相思Acacia confusa、桃树Prunus persica、苦楝Melia azedarace、板栗Castanea mollissima、桂花Osmanthus fragrans、枇杷Eriobotrya japonica、三角梅ougainvillea spectabilis和窿缘桉Eucalyptusexserta等9种植物为该虫潜在寄主。4.首次系统地明确了桉蝙蛾生物生态学特性。该虫在广西1-2年1代,以幼虫在树干蛀道中越冬,老熟幼虫2月开始化蛹,成虫4月羽化,于黄昏飞行交配,交配时间长达24h。雌蛾平均产卵量9161粒,卵平均孵化率为74.37%。幼虫经历地栖和树栖2个发育阶段,1-4个月生活在地面森林落叶层或朽木中,真菌是其主要食物之一,8-11个月(2年1代为20-23个月)生活在活立木树干中,主要取食韧皮部,幼虫龄期为9龄。1～8年生桉树林均可受害,主要危害1-3年生幼树(占76.53%),海拔300m以下低丘沟谷地带受害较重；虫害木段室外风干或10℃的冰箱中冷藏,其幼虫均能存活3个月以上,重新转移寄主活立木,除冷藏3个月外均能钻蛀恢复生长并完成世代。5.揭示了桉蝙蛾与主要钻蛀性害虫的生态位关系。桉蝙蛾幼虫集中在0～2m桉树树干(占总虫数70.60%),云斑白条天牛幼虫集中在0-1m的主干处(占总虫数83.51%),咖啡豹蠹蛾幼虫集中在3-7m的中部树干(占总虫数84.52%)。生态位宽度,咖啡豹蠹蛾>桉蝙蛾>云斑白条天牛；生态位相似性,桉蝙蛾和云斑白条天牛>桉蝙蛾和豹蠹蛾>云斑白条天牛和豹蠹蛾；种间竞争系数,桉蝙蛾和云斑白条天牛>桉蝙蛾和豹蠹蛾>云斑白条天牛和豹蠹蛾。咖啡豹蠹蛾对空间资源的利用程度最大,桉蝙蛾次之,云斑白条天牛最小。6.探明了桉蝙蛾幼虫种群空间格局。标准地小尺度下,生物学统计和地统计学分析种群空间格局均为聚集分布,轻、中、重受害程度变程α分别为20.00m、40.38m和69.42m。省际大尺度下地统计学分析,幼虫种群在轻度受害呈随机分布,在中度和重度受害呈聚集分布,轻、中、重度受害下变程α分别为43.6km、15.5km.12.47km。7.掌握了桉蝙蛾天敌资源。已发现该虫天敌31种,其中寄生蝇1种,寄生蜂4种,捕食性蚂蚁12种,其它捕食性天敌6种,虫生真菌8种。幼虫和蛹以白僵菌、寄生蝇、蚂蚁和鼠类为主,成虫以蝙蝠、鼠类、蟾蜍和蛇类为主,卵的天敌有蚂蚁、蠼螋和青霉。不同地点采集桉蝙蛾白僵菌菌株分子测序结果证实存在遗传差异。栗色舟寄蝇Scaphimyia castanea Mesnil和球孢白僵菌Beauveria bassiana (Bals.)自然控制能力较强,林间球孢白僵菌平均感染率为11.30%,栗色舟寄蝇平均寄生率为4.64%。更多还原

【Abstract】 Eucalyptus (Myrtaceae) is native to Australia and has been widely cultivated all over the world. There are now about4million hm2of Eucalyptus plantations in China and the cultivating area is expanding to10provinces or municipalities in southern and southwest China. Guangxi is the most Eucalyptus plantations province (the area is1.82million hm2, accounted for46%of the total Eucalyptus plantations in China). With the large-scale Eucalyptus cultivating and unscientific management in China, most native insects transfered to feed on Eucalyptus and have caused more serious damage. Endoclita signifer Walker is the most serious infestation wood borer on Eucalyptus newly found in Guangxi and Guangdong provinces in recent years. However, information about E. signifer biology and ecology was very limited in China and worldwide. The current study reports its geographic distribution and damage, host plant range and natural enemy, bio-ecological characteristics, population dynamics associated with Eucalyptus plantations.1. The geographic distribution and damage of main wood borer on Eucalyptus in Guangxi have been surveyed.3orders,7families and13species wood borers on Eucalyptus have been found, among them, E.signifer infested in60counties and the infestation area was3536.30hm2, Batocera lineolata infested in8counties and the infestation area was204.38hm2, Zeuzera coffeae infested in9counties and the infestation area was199.13hm2. Found a new wood borer on Eucalyptus, Synanthedon jinghongensis Yang et Wang.2. The eucalyptus timber volume and economic loss caused by E. signifer had been assessed. In the plantations of light, moderate and severe infestation by E. signifer, the average individual timber volume and biomass loss was0.0110m3and6.38kg,0.0126m3and12.28kg,0.0221m3and20.87kg, respectively, the total timber volume loss was0.495m3/hm2,1.512m3/hm2and4.973m3/hm2, respectively. Assessed with current prices of the Eucalyptus timber, the total timber volume and quality loss was￥1253,￥3494and￥8335per hm2in light, moderate and severe infestation plantations, respectively. The timber volume loss was significant difference between more than4per tree and less than3per tree of larvae density.3. Natural and potential host plants of E. signifer had been investigated and determined basicly. The natural host plants of E. signifer included21families,31genus and39species. Myrtaceae, Mimosaceae, Euphorbiaceae, Oleaceae, Verbenaceae, Ulmaceae and Vitaceae were common host plants of E. signifer. The Eucalyptus plantations of Eucalyptus urophylla, E.grandis×E. urophylla, E.urophylla×E. grandis and E.grandis×E. tereticornis were infested disproportionately. The plantations of E. grandis, E. camaldulensis, E. saligna, E. globules and E. citriodora were not found attacking by E. signifer. A new method for potential host plants determination of wood borer was invented.14families,18genus and20species of plants were determinatetd, nine plants of them, Cunninghamia lanceolata, Acacia confuse, Prunus persica, Melia azedarace, Castanea mollissima, Osmanthus fragrans, Eriobotrya japonica, ougainvillea spectabilis and E. exserta were confirmed as potential host plants of E. signifer. 4. The bio-ecological characteristics of E. signifer had been first systematically revealed. E. signifer took one or two year to complete a generation in Guangxi. The insects overwinter as larvae in tunnels in wooden stems. The final instar larvae began pupating in February, adults began emergce in April and mating flight in the evening, the duration of mating was up to24h. The average number of dropping eggs was9161per female and hatching rate of eggs was74.37%. The larvae had two of litter and live tree developmental stages.1～4months live in the forest floor litter or decaying wood, fungus was one of its main food.8～11months (20～23months for2years a generations) live in live tree stem, mainly feed on phloem. Larval had nine instars.1-8year-old Eucalyptus plantations were infested, mainly damaged1-3year-old plantations (accounted for76.53%), the hilly and valley areas under300m altitude were infested seriously. The infested tree stems that contained E. signifer larvae were put outdoor area for drying or put into refrigerator at10℃for refrigeration, the larvae in the treated stems could survive for more than3months, after transferred to live host tree, the larvae could bore into new stem to restore growth and completed its generation except been refrigerated for3months.5. The spatial niches of the major wood-boring pests on Eucalyptus were studied. E. signifer larvae mainly bored at0-2m height of the host trunk (accounted for70.60%of total larvae). B. lineolata larvae mainly bored at0～1m height of the trunk (accounted for83.51%of total larvae). Z. coffeae larvae mainly bored at3-7m height of middle trunk (accounted for84.52%of total larvae). The niche breadth index showed that Z. coffeae> E. signifer> B. lineolata. The niche similarity index showed that E. signifer&B. lineolata> E. signifer&Z. coffeae> B. lineolata&Z. coffeae. The interspecific competition coefficient showed that E.signifer&B. lineolata> E.signifer&Z. coffeae> B. lineolata&Z. coffeae. The use of spatial resources was Z. coffeae> E. signifer> B. lineolata.6. The spatial distribution pattern of E. signifer larvae was revealed. In small size, the spatial distribution pattern of E. signifer larvae was aggregated pattern. The distance of spatial dependence of E. signifer larvae at slight, moderate and serious infestation was20.0m,40.3m and69.4m, respectively. At large size, the spatial distribution pattern was random at slight infestation, aggregated at moderate and serious infestation. The distance of spatial dependence of this pest was43.6km,15.5km and12.47km, respectively at slight, moderate and serious infestation.7. Natural enemies of E. signifer were investigated.31species natural enemies of E. signifer were found, one species of parasitic fly,4species of parasitic wasps,12species of predatory ants,6species of other predator,8species of entomogenous fungi. The larvae and pupae mainly controlled by Beauveria bassiana (Bals.), flies, ants and rodents. Adult mainly controlled by bat, rodents, toads and snakes. Eggs were controlled by ants, earwigs and penicillium. The4rDNA-ITS test results showed that there were genetic differences among B. bassiana strains from different infected sites. On field survey, Scaphimyia castanea and B bassiana had higher natural control ability for E. signifer, the average controlled rate of B. bassiana and S. castanea was11.30%and4.64, respectively.更多还原