【作者】 赵微微；

【导师】 李鑫；

【作者基本信息】 西北农林科技大学 ， 有害生物治理生态工程， 2009， 硕士

【摘要】 通过对山楂叶螨室外调查与室内追踪观察试验,基本明确各螨态形态变化和叶片的为害程度,并对其空间格局和孵化、交配行为以及单叶叶相变化进行了研究。结果表明:7～10月山楂叶螨在苹果树冠不同高度和不同方向均呈聚集分布,平均拥挤度为上层>中层>下层,南侧>东侧>西侧>北侧,外层>内层。7～10月前期山楂叶螨在苹果树冠的水平方向和垂直方向均表现高聚块、后期低聚块,冠内叶片老化而种群量低。该螨在树冠内层容易聚合、外层相反,其密度内层高,外层低;长时间的强降雨可迅速降低树冠叶螨种群数量,短时间的降雨对树冠上层螨量影响显著。因此,7～10月对苹果园山楂叶螨的管理关键是注意树冠内堂,并根据降雨的强度和持续时间采取灵活的措施进行防治。室温下,观察其卵孵化与雌雄螨交配行为。结果显示:雄螨主动从雌螨腹末钻入腹下,同时翘起、上卷腹末,直对雌螨生殖孔,与雌螨腹部在生殖区构成一直线形。山楂叶螨的交配过程,可划分为5个阶段:寻找、确认、交配前、交配和交配结束。雌、雄螨一生均多次交配,且不同代间也发生。第一次交配时间长,最长达540 s,后续交配时间明显缩短;山楂叶螨卵的孵化时长,与卵所在位置有一定关系;孵化时,幼螨多借助于卵周围其它杂物以蹬、扶、扒等形式,挣脱卵壳,此时个体耗时短,最短时仅4 min。拟定叶相等级,单叶接螨1头、3头、5头,观察记录叶螨繁殖情况和叶相变化。得知:单叶螨源基数与叶片受害程度明显呈正比。在6月-8月,当单叶雌螨量达到5头时,就应采取适当的控制措施;山楂叶螨在室温29.29℃±4.73、RH 66.63 %±24.78条件下,自然光照射,并给予有限食物时,一个月可发生2个完整世代和一个不完整的世代;接5头叶螨的叶片23 d出现灾变点,叶相达4级为害状,叶片营养损失严重。在螨量有增无减的情况下,导致叶枯,对叶螨的灾难发生,种群失去生存条件,出现二次发芽。当叶相变化为2级受害状时,最适合防治,此时螨量小,且对叶片还未造成大损失。综合对山楂叶螨室外调查与室内追踪观察的结果可见,该种群扩散行为与食物质量、种群密度密切相关,同时受温湿度、降雨、喷药等环境因素影响。山楂叶螨种群趋向于外围阳光充足的质量高的叶片;当受害叶片呈4级为害状时,叶螨种群扩散活动频繁,欲选择更优质的食物资源。更多还原

【Abstract】 We had a clear understanding on states change and the extent of leaves damage of Tetranychus viennensis Zacher through outdoor and indoor surveying, as well as, its spatial pattern and hatching、mating behavior and single leaf change were studied further, The results show that:The spatial distribution pattern of Tetranychus viennensis from June to October was an aggregative one, and mean crowding from strong to weak: upper layer> middle layer> under layer, south side> east side> west side> north side, and outer layer> inner layer. From June to October, it shows high density in both horizontal and perpendicular direction in prophase, but low in anaphase, population quantity decreases along with leaf aging. Tetranychus viennensis prefers inner side of crown to aggregate than outer side, so it shows the highest intimate degree in inner side and the lowest in outer side. Longtime heavy rainfall decreases the population quantity in crown rapidly, and short time rainfall affects upper layer of crown prominently. During this period, attention should be paid to the inner side of crown, and a flexible control should be applied according to the intensity and duration of rainfall.At room temperature, we observed its hatching and mating behaviour. The results revealed that males go into abdominal end of females actively, at the same time, tilt and volume abdominal end, and the female reproductive area in the abdomen has been linear composition. The matching process of tetranychus viennensis can be divided five phases, that is, find,affirm, ecdysis,matche and finish. Tetranychus viennensis could have a number of matings in its lifetime, could matched in different inter-generational. The first mating time was very long for a maximum of 540 s, the follow-up time was significantly shorter; eggs hatching duration of Tetranychus viennensis were very long, to some extent had to do with the location of eggs; when hatching, the larvae can break the egg shell by something around egg, and the individual consuming short time, the shortest only 4 min.Set the level of leaves development, took one、three、five Tetranychus viennensis to single leaf, observed and wrote down the reproduction situation and leaf phase changes of single-leaf. We knew that: the source basewe has proportional to leaves damage. Between June and August when there was fiveTetranychus viennensis in single leaf, it was the most appropriate prevention and treatment period; At temperature 29.29℃±4.73, humidity 66.63%±24.78, exposure to natural light and gave limited food, there was two complete generations and a not complete generation in a month; The leaves had five Tetranychus viennensis appeared catastrophe points in 23 d, they reached up to four-level damage, leaves loss more nutrient . When the number increased, leaded to leaf blight. It was the most appropriate prevention and treatment period when the leaves showed two-level damage ,because the number was less ,easy to control.We found that population diffusion of Tetranychus viennensis was closely related to population density and food quality integrating Outdoor survey and indoor follow-up observation, at the same time, it was affected by temperature and humidity、rainfall、spraying and other environmental factors. Tetranychus viennensis population tended to be the outside sunny、high-quality leaves. Its population diffuse frequently when the leaf showed four-level damage .更多还原