【作者】 刘永华；

【导师】 骆有庆； 宗世祥；

【作者基本信息】 北京林业大学 ， 森林保护学， 2014， 博士

【摘要】 沙棘在我国三北地区生态建设中具有十分特殊的重要地位和作用。近年来,食叶害虫栎黄枯叶蛾(Trabala vishnou giganina Yang)在陕西吴起县沙棘人工林中大面积暴发,严重影响沙棘林的生态稳定性。以往仅有栎黄枯叶蛾生物学和防治措施的简要报道,本文首次对其生物生态学特征、性引诱效果、寄主选择行为、幼虫两色型现象等方面进行了较系统的研究,为其综合治理提供了科学依据。主要研究结果如下：1、通过野外调查和室内饲养观察,明确了栎黄枯叶蛾的生物学特性：在陕西吴起,该虫1年1代,以卵块在茧表面、枝条及枯枝落叶等处越冬；翌年5月中下旬开始孵化,7月下旬开始结茧化蛹,蛹期平均(24.5±3.1)d；成虫始见于8月下旬,终见于9月下旬,羽化高峰期为9月上旬。成虫寿命为6-13d。雌虫交尾后即可产卵,平均产卵量可达297粒。2、应用聚集度指标和回归模型分析,明确栎黄枯叶蛾幼虫的空间分布属于聚集分布。分布的基本成分为个体群,聚集程度随密度增加而增强,而引起幼虫聚集的原因主要为其生物学特性,其次为环境因素。在此基础上,确定了栎黄枯叶蛾幼虫的田间最适抽样数和序贯抽样表。3、系统地明确了栎黄枯叶蛾生长发育规律：卵的发育起点温度C=9.24±0.45℃,有效积温K=341.22±9.54日度；幼虫的发育起点温度C=10.85±0.87℃,有效积温K=1285.64±17.65日度；蛹的发育起点温度C=14.56±0.85℃,有效积温K=445.35±8.65日度。明确其幼虫共有7龄,头壳宽度、额宽、上颚基部宽和单眼间距等可作为幼虫分龄的主要依据。4、明确了栎黄枯叶蛾成虫行为学的基本特性：羽化期40d左右,日羽化高峰在17：00-23：00,占全天羽化量的82.46%；雌雄性比为1：1.41；未交配雌蛾和雄蛾的平均寿命为11.05d和9.85d,高于已交配雌蛾和雄蛾的8.05d和7.35d。处女雌蛾诱集雄蛾的高峰在4：00左右,3：00-5：00诱蛾量占总诱蛾量的68.2%；2日龄处女雌蛾诱蛾量显著高于1日龄,3日龄略有减少,4-6日龄雌蛾诱蛾活性逐渐降低。羽化翌日即可交配,雌蛾一生只交配1次,雄蛾可进行多次交配。2日龄雌蛾交配率最高,达到45.6%。交配高峰期在3：00-4：00。单次交配持续时间多为14-16h。交配后即可产卵,产卵高峰期在2：00-6：00,占全天产卵量的82.40%。未交配雌蛾也能产卵,产卵量与已交配雌蛾的产卵量接近,但均不能孵化。总之,栎黄枯叶蛾成虫羽化、交配和产卵行为均集中在后半夜,具有明显的时辰节律。5、明确了栎黄枯叶蛾取食和产卵选择行为。结果表明幼虫在野外主要以沙棘叶片为食,仅发现少量幼虫取食山杏叶片。室内进行的幼虫取食选择实验发现,所有树种均可取食,但低龄幼虫选择性较强,高龄幼虫选择性明显降低。野外调查发现,成虫对产卵处有明显的选择性,由高到低依次为茧壳、沙棘、刺槐、拧条和杂草。而在不同产卵处产卵量无明显差异。在室内选择沙棘、刺槐、拧条、山杏、柳树和杨树作为试验树种,发现沙棘上的落卵量最高,杨树最低。6、揭示了栎黄枯叶蛾幼虫具有鲜明的两色型现象,但不存在幼虫性二型现象。首次明确了4龄幼虫后具有白色型和黄色型的分化,白色型幼虫体色一直保持白色。黄色型幼虫每次蜕皮后变为白色,3-4天内逐渐变为黄色。白色型幼虫的取食量较大,生长发育较快,繁殖能力较强,而黄色型幼虫的死亡率较低、耐饥饿能力较强。虫口密度和温度是影响栎黄枯叶蛾幼虫色型变化的重要因素,在一定范围内随温度和密度升高,白色型幼虫所占比例逐渐升高,黄色型幼虫比例则下降,而湿度、光照对色型比例没有影响。更多还原

【Abstract】 Seabuckthorn is playing a special important role in the ecological construction in Three North area. In recent years, the leaf-eating pest Trabala vishnou gigantina Yang has broken out in Wuqi county of Shaanxi, and has seriously affected the ecological stability of seabuckthorn plantations. There are few scientific researches being published on this moth in China or abroad. The bio-ecology, sex attractant effect, host selection behavior, and two color morph phenomenon of the larvae have been investigated for the first time in this research, which would provide a scientific basis for integrated management. The main results and conclusions are as follows:(1) The research results of biological characteristics through field survey and laboratory breeding and observation indicated that a generation takes one year in Wuqi of Shaanxi. The eggs were found to overwinter on cocoon、branch and litter. Eggs begin to hatch in the mid or late May. Larvae begin to pupate in late July, with the average pupal stage lasting24.5±3.1d. Adults emerge from late August to late September, with the peak of eclosion in early September. The longevity of adults is6-13days. Female adults start oviposition on2d after the emergence, and the average fecundity is about297per female.(2) The spatial distribution of larvae of T.vishnou gigantina were analyzed using the aggregation indices and the regression model. The results showed that the spatial pattern of larvae was aggregation distribution. The basic componernt of distribution was individual colony. The aggregation increased generally with the increasing density. The reason for aggregatied may be its bionomics and other environmental factors. Based on the distribution pattern, the optimal sampling number and sequential sampling table were calculated.(3) The developmental period, developmental threshold temperature and effective accumulated temperature of different life stages of T.vishnou gigantina were determined in the laboratory. The results indicated that the developmental periods of life stages decreased in length with increasing temperature. The developmental threshold temperature of eggs, larvae and pupae were9.24±0.45,10.85±0.87and14.56±0.85respectively, and their effective accumulative temperatures were341.22±9.54,1285.64±17.65and445.35±8.65degree day respectively. The numbers of larval instars were determined using coefficient of variation and Crosby ratio through field sample. Larval stage comprised seven instars and the head capsule width was the best instar-dividing structure. Three variables including distance between simple eyes, cranial width and mandible width could be used for the separation of larval instars for the sclerotized structures.(4) The eclosion, mating and oviposition were studied through field survey and laboratory breeding and observation. The results showed that the emergence period of the pest lasted for40days. The daily emergence peak occurred from17:00to23:00, and counted82.46%to the number of daily emergence. The ratio of female to male was1:1.41. The lifespan of the unmated female and male were averagely11.05days and9.85days respectively, whereas that of the copulated female and male were8.05days and7.35days on average respectively, indicating that mating shorten the lifespan of male. In the field tests, the highest percentage of the male moths was trapped during3:00-5:00, and more males were trapped by2-day-old virgin female moths than by female moths of other ages. The mating rate on the second night was the highest (45.6%) and then decreased gradually. The mating peak took place from3:00to4:00. Females normally copulated only once in their whole life span, with several times for males. For most of the adults, the duration of mating was14～16hours. Approximately82.40%of eggs were laid during night time. The unmated female could lay eggs, but those unfertilized eggs couldn’t hatch. The emergence activity, the mating activity and the oviposition activity were synchronized at different ages and time of the scotophase.(5) Results of the feeding and oviposition preference of T. vishnou gigantina showed that the feeding amount on H. rhamnoides were the biggest while just a few moths emerged from Prunus armeniaca. No moth was found on other plant species in the field. The feeding preference tests in the laboratory showed that the moths could feed on all plant species, and young larvae had more stronger selective than old ones. Results of the field survey indicated that the amount of eggs on different species ranked as:cocoon shell> H.rhamnoides> Robinia pseudoacacia> Caragana Korshinskii> weeds. The oviposition preference tests in the laboratory showed that the number of eggs on H.rhamnoides was the maximum, and the minimum was on Populus davidiana.(6) The differentiation of the larval color morph of T. vishnou gigantina was studied through laboratory breeding and observation. The results showed that the larvae had a distinct two color morph phenomenon, but there was no larval sexual dimorphism. The larvae began to differentiate into white morph and yellow morph at the4th instar. Color of the white morph larvae kept white and unchanged, while yellow morph larvae changed to white after molting, and then graded gradually from white to yellow in three or four days. The white morph larvae had the characteristics of greater food consumption, faster body growth and stronger reproductive capacity, while yellow morph larvae had the characteristics of higher survival rate and stronger starvation resistance. In a certain range, numbers of white morph larvae increased with the increasing of temperature and population density. It was not related with humidity and light.更多还原