【作者】 王建伟；

【导师】 骆有庆； 宗世祥；

【作者基本信息】 北京林业大学 ， 森林保护， 2011， 博士

【摘要】 油蒿(Artemisia ordosica)(菊科)是我国西北地区常见的防风固沙植被,大面积飞播油蒿对我国荒漠地区的土质改善、植被群落的建立、生态环境的保护有着极其重要的意义。沙蒿木蠹蛾(Holcocerus artemisiae Chou et Hua)鳞翅目：木蠹蛾科)、沙蒿大粒象(Adosomus sp.)(鞘翅目：象甲科)和沙蒿尖翅吉丁(Sphenoptera sp.)(鞘翅目：吉丁科)是危害油蒿的重要钻蛀性害虫,以幼虫蛀食根部和主干,造成树势衰弱甚至整株枯死,近年来在宁夏、内蒙古、陕西等地区大面积发生,对油蒿灌木林的健康以及荒漠地区的生态环境构成了巨大威胁。本文对钻蛀性害虫的生物生态学特征、害虫种群生态位、沙蒿木蠹蛾性诱剂的诱捕技术标准化、天敌资源的调查及应用等进行了研究,主要结果如下：1、首次系统地明确了三种油蒿钻蛀性害虫的生物生态学特征：室外调查和室内饲养的研究表明,在宁夏,沙蒿木蠹蛾2年1代,以幼虫在被害根部越冬。老熟幼虫于5月中旬从根部钻出,在周围的沙土里结茧化蛹,蛹期平均20d；成虫期6月初-8月末。成虫羽化当日即可交配,雄虫有2次交尾现象。卵初见于6月中旬,初孵幼虫初见于6月下旬。幼虫蛀食坑道不规则,常单独危害,且具有转移危害的习性。沙蒿大粒象1年1代,以成虫和老熟幼虫在根部越冬。越冬成虫始见于4月中下旬,终见于6月中旬；越冬老熟幼虫5月中旬开始化蛹,成虫期6月下旬-8月上旬。成虫取食油蒿叶片补充营养。沙蒿尖翅吉丁1年1代,以幼虫在被害根部越冬。老熟幼虫于4月中下旬化蛹,成虫期5月上旬-7月上旬。成虫取食叶片补充营养,2-7d后开始交尾,集中在13:00-16:30,雌雄成虫均可多次交尾。幼虫常多头聚集危害同一株油蒿。2、采用林间定期调查取样法明确了幼虫龄数：沙蒿木蠹蛾幼虫为7龄,沙蒿大粒象和沙蒿尖翅吉丁幼虫均为4龄。各幼虫测量指标符合Dyar氏的幼虫头壳增长规律,测量指标的对数值与龄数之间的指数模型拟合较好。3、通过扫描电镜观察,明确了沙蒿木蠹蛾和沙蒿尖翅吉丁触角感器的类型和分布规律：沙蒿木蠹蛾触角共有7种类型的感器,包括1种毛形感器、1种锥形感器、3种鳞形感器、1种腔锥形感器和Bohm鬃毛。其中,毛形感器的数量最多,触角背面毛形感器的密度大于触角腹面。沙蒿尖翅吉丁触角共有10种类型的感器,包括2种毛形感器、5种锥形感器、1种腔锥形感器、表皮孔以及Bohm鬃毛。雌雄成虫以及触角背腹面的触角感器类型、数量以及分布特点存在明显差异。4、揭示了油蒿主要钻蛀性害虫种群的时空生态位：时间生态位指数表明,沙蒿尖翅吉丁对油蒿的危害时期较长,和沙蒿木蠹蛾的危害时间较为一致。空间生态位指数显示,沙蒿大粒象对油蒿根部资源利用更充分,沙蒿尖翅吉丁与其他三种害虫在油蒿上的分布趋于分离,对资源的共享程度较小。5、建立了沙蒿木蠹蛾和沙蒿大粒象幼虫的人工饲养技术：结果显示幼虫更喜欢取食含油蒿木屑的饲料。沙蒿木蠹蛾幼虫的化蛹率为27.89±4.08%,羽化率平均为11.25±15.91%。沙蒿大粒象幼虫的化蛹率为46.17±26.58%,化蛹率为42.67±29.14%。湿度和防腐剂的浓度可能是影响幼虫发育的重要因素。6、基本揭示了油蒿灌木林趋光性昆虫的种类和群落结构：趋光性昆虫共有6目25科94种。鳞翅目昆虫在数量上占有绝对的优势(88.83%),且物种丰富度最高(63种),以夜蛾和天蛾科昆虫为主。膜翅目和脉翅目昆虫多为天敌。昆虫群落、害虫亚群落和天敌亚群落的群落个体数量、丰富度、多样性和均匀度在5-9月间波动变化。趋光性昆虫对不同波长的诱虫灯具有选择性。常用波长365nm诱虫灯诱集总数低于其他波长,其中波长368nm诱虫灯诱集数量最多,高出对照灯近90%。波长335nm诱虫灯对木蠹蛾科、螟蛾科和灯蛾科昆虫的诱集数量较多；波长345和351nm诱虫灯对天蛾科的诱集效果最好；波长368nm的诱虫灯对夜蛾科的诱集数量较多。比较天敌的诱集情况,波长351nm的诱虫灯对茧蜂和草蛉的诱集数量较少,波长365nm诱虫灯对蝎蛉诱集数量较少。7、定量明确了沙蒿木蠹蛾性诱剂在野外的时空诱集效果：结果显示,上风口的诱捕效果最好,诱捕量占到诱捕总量的60%,侧风口的效果好于下风口;在上风口设.置距林缘不同距离的诱捕器,距林缘30-210m处均能诱捕到成虫,但以60m处诱捕到的数量最多；性诱剂的持效期为27.75±2.56 d；船形和三角形诱捕器的诱捕数量明显多于十字形诱捕器。除了沙蒿木蠹蛾,还对草地螟(Loxostege sticticalis)、冬麦异夜蛾(Protexarnis squalid)和蜂虻科(Bombyliidae)昆虫等有明显的诱捕效果。8、首次发现了重要天敌麦蒲螨(Pyemotes tritici)自然寄生钻蛀性害虫的现象,寄生率为15.08±2.35%;通过实验建立了人工扩繁技术：麦蒲螨能寄生沙蒿尖翅吉丁的幼虫、蛹以及沙蒿大粒象的幼虫和蛹,并产生膨腹体,使沙蒿木蠹蛾幼虫麻痹甚至死亡,但无法产生膨腹体。除了原始寄主,麦蒲螨还可以寄生多种害虫,包括大蜡螟(Galleria mellonella)、红缘天牛(Asias halodendri)、青杨枝天牛(Saperda populnea)、柠条绿虎天牛(Chorophorus sp.)、以及榆木蠹蛾(Holcocerus vicarius)幼虫,其中寄生大蜡螟幼虫时间短、寄生率高、产生膨腹体数量较稳定,是理想的替代寄主。在5-15℃的条件下,成螨的存活率随时间的延长而降低,12天后平均存活率降到20%以下,16天后平均存活率为5%左右。利用麦蒲螨进行了初步的防治试验,结果显示,麦蒲螨可以在自然条件下能找到并成功寄生寄主,但寄生率低于30%。高温和蚂蚁咬噬会显著减少麦蒲螨的种群数量。9、针对油蒿灌木林分布广、物种单一、生态脆弱的特点,运用生态调控理论,构建了油蒿钻蛀性害虫生态调控技术体系。通过分析遥感影像数据、调查虫害发生情况和采集环境因子数据,在一定程度上可对油蒿的健康程度以及虫害发生情况进行监测。通过沙蒿木蠹蛾性诱剂的标准化使用,准确掌握虫害发生情况并及时防治。利用油蒿植物源引诱剂,结合适合的诱捕器,在一定程度上监测沙蒿尖翅吉丁和沙蒿大粒象的发生。通过人工繁育和释放寄生性天敌麦蒲螨,对沙蒿大粒象和沙蒿尖翅吉丁的种群进行控制。在野外设置波长335和368 nm的诱虫灯,加强对沙蒿木蠹蛾的诱集效果。更多还原

【Abstract】 Artemisia ordosica (Asteraceae), is a plant used widely for windbreak and. sand fixation in northwestern China. Large areas of aerially seeded A. ordosica play a significant improving in soil conditon, establishing vegetation communities and protecting the environment. Holcocerus artemisiae (Lepidoptera:Cossidae), Adosomus sp.(Coleoptera:Curculionidae), Sphenoptera sp. (Coleoptera: Buprestidae) and carpenter moth (Lepidoptera:Tortricidae) are the main pests,boring into roots and stems of A. ordosica, causing weak growth and even death of the plants. Damage caused by these pests has become an increasingly serious problem in Ningxia, Neimenggu and Shannxi Provinces, threatening the health of desert shrubs and the environment. The following aspects were systematically examined and discussed in this study:the basic bio-ecology characteristics of the main boring insects, the ecological niches of these pest and the ffect of applied synthetic sex pheromones on H. artemisiae. An investigation was also made into using a natural enemy of boring insects (Pyemotes tritici) as a bio-control agent.. The main results of the study are outlined below.1. The basic bio-ecological characteristics of three pests were systematically clarified for the first time. The results showed that:the artemisia carpenter moth, H. artemisiae (Chou and Hua) (Lepidoptera: Cossidae) had a two-year generation time. Larvae of all instars were found overwintering in roots. Mature larvae began to pupate in mid-May in the sand around the roots with the average pupal stage lasting 20 days. Moths emerged from the beginning of June to the end of August with adult able to copuate after emergence. Female moths started laying eggs around mid-June and the eggs hatched in late June. Individual larvae consumed a single root in irregular tunnels before transferring to another. The artemisia weevil, Adosomus sp. (Coleoptera:Curculionidae) occurred as one generation each year and overwintered as mature larvae or adults in roots. Overwintering adults appeared from mid- or late-April to mid-June, and overwintering larvae began to pupate in mid-May. Adults emerged from late-June to early-August, and fed on leaves to supplemental nutrition. The artemisia buprestid, Sphenoptera sp. (Coleoptera:Buprestidae) had one generation per year, and all larval instars overwintered. Mature larvae began to pupate in mid to late-April at the end of the gallery. Adults emerged from early-May to early-July and ate fresh leaves for before copulating. Copulation occurred between approximately 13:00-16:30, and adult were observed to mate several times. Larvae often aggregated in one root and overwintered in stems and roots.2. Instars of these three pests were established from larvae samples collected from the field. There were seven instars in H. artemisiae, and four in both Adosomus sp and Sphenoptera sp. The relationship of different instars and head width, first established by Dyar, showed an exponential regression with these insects.3. The type and distribution of antennal sensilla in H. artemisiae and Sphenoptera sp. were examined with scanning electron microscopy (SEM). The H. artemisiae sensilla were classified into seven types, including sensilla coeloconica, Bohm bristles, two types of sensilla trichodea and three types of sensilla squamiformia. The sensilla trichodea were the most numerous and their density was higher on the dorsal side of the antenna than that on the ventral side. In contrast, there were ten types antennal sensilla on the antenne of Sphenoptera sp., including sensilla coeloconica, pore sensilla, Bohm bristles, two types of sensilla trichodea and five types of sensilla basiconica. There were differences between males and females, and dorsal and ventral antenna side in type, number and distribution.4. The temporal and spatial niches of the major boring insects were investigated. Time niche index showed that the damage period of Sphenoptera sp. was much longer than that of the others, and it showed some overlap with the damage period of H. artemisiae. A spatial niche index showed that the distribution of Adosomus sp. larvae was wider than the other species of insects studied. The distribution of Sphenoptera sp. larvae and the other insects tended towards separation and there was much difference in resource utilization between them.5. Artificial rearing of H, artemisiae and Adosomus sp.larvae was carried out. They preferred the artificial diet containing sawdust from A. ordosica roots and stems. H. artemisiae pupation rate was 27.89±4.08% and adult emergence rate was 11.25±15.91%. The Adosomus sp. pupation rate was 46.17±26.58% and the emergence rate was 42.67±29.14%. Humidity and the antiseptic concentration appeared to affect larval development.6. The composition and structure of the phototaxis insect community in desert shrubs were defined. All the insects collected belonged to 6 orders,25 families, and 94 species. Lepidopteran insects had the highest number of individuals (88.83% of total number) and the highest species number (63 species). Most of the natural enemy insects belonged to Hymenoptera and Neuroptera. Indices of pest and natural enemy number and species richness first increased then decreased during the investigation, with peaks from June to August. The phototaxis insects showed significant selectivity to different light wavelengths. The number attracted to back-light of 365nm was the lowest, and to 368nm was the highest (90% more). Back light of 335nm attracted more moths of Cossidae, Pyralidae and Arctiidae, back light of 351nm attracted more Sphingidae moths and back light of 368nm attracted more Noctuida moths. For the parasitoids and predators, the lowest Braconidae and lacewings were lured by back light of 351nm. The fewest Panorpidae (8.35%) were also lured by back light of 351nm.7. Field trials of sex pheromones for Holcocerus artemisiae were measured quantitatively. Results indicated that trapping upwind was optimal (60% of males), and trapping crosswind was better than that of downwind. Males were trapped 30-210 m upwind, with the largest trapping numbers at 60 m. This sex pheromone could last up to 25-34 days. The boat and triangle traps were effective than practical novel types. In addition to H. artemisiae, the sex attractant also attracted Loxostege sticticalis, Protexarnis squalid and Bombyliidae.8、Parasitic enemy Pyemotes tritici was first reported as an natural control factor for boring insects, and its artificial cultivation was established. P. tritici parasitized larvae and pupae of Sphenoptera sp. and Adosomus sp., with an average parasitic rate of 15.5%. Artificial rearing of P.tritici revealed that it can reproduce on several species of boring insects, including Galleria mellonella, Chorophorus sp., Asias halodendri, Saperda populnea and H. vicarius larvae or pupae, but not on H. artemisiae. Because of a short parasite time and high reproduction ratio, A. halodendri was chosen as the ideal artificial host insect. Tying the mouthpart of G. mellonella larvae with thread improved the parasitic rate. The survival ratio of mites kept at 5-15℃decreased with time, and fell below 20% after 12 days. After 16 days, the P.tritici population became too small to control the pests. Pest control experiments performed both in the laboratory and in the field showed that P. tritici could find host larvae and parasitize them, but the ratio was lower than 30%. Extremely high temperature and ant-predation could reduce the mite population, affacting parasitism upon the host species.9、Combining general principles and methods of ecological mediation for pest control with the features of large area, single-species and ecological fragile desert shrubs, several measures were put forward to establish an ecological mediation system reducing damage by boring insects. Based on the analysis of remote sensing image data and investigation into the boring pests in A. ordosica and associated environmental factors, the relationship between remote images, plant health and pest occurrence needs to be established, in order to monitor the health of A. ordosica and pests occurrences. Standardized using of sex pheromone for H. artemisiae provides an efficient method to monitor and control the adults. A. ordosica plant source attractants can be used to monitor populations of Adosomus sp. and Sphenoptera sp. adults, combined with some suitable traps. In oeder to control these two pests effectively, application of laboratory-reared P tritici is strongly recommended. In addition, the use of 335 and 368 nm black lights are recommended for attracting more H. artemisiae moths.更多还原