【作者】 李小珍；

【导师】 刘映红；

【作者基本信息】 西南农业大学 ， 农业昆虫与害虫防治， 2004， 硕士

【摘要】 二点叶蝉bipunctella(Mats)隶属于同翅目Homoptera，叶蝉科Cicadellidae，殃叶蝉亚科Euseelinae，叶蝉属Cicadulina，是禾本科植物上的一种微小昆虫。我国主要分布于四川、重庆、贵州的多个县市。它取食农作物玉米和小麦，导致营养物质直接损失，更甚的是传播一种具有毁灭性、流行性和爆发性的病害——玉米鼠耳病。本研究着眼于二点叶蝉与玉米鼠耳病的发生和治理现状，从它们之间的关系出发，采用室内实验研究与田间调查相结合的方法，综合运用昆虫种群生态学和病害流行学的原理和方法，对二点叶蝉的生物生态学特性、二点叶蝉的致病性、玉米鼠耳病的田间动态及综合治理进行了研究探讨。主要研究内容和结果如下： 1 二点叶蝉实验种群的建立 调查四川省南充市仪陇县玉米地的昆虫种类、对这些昆虫进行室内实验与鉴定。结果表明，二点叶蝉是玉米鼠耳病的主要介体，可导致玉米发生典型的鼠耳病。室外采集、从卵分离、蜕皮分离及单头饲养分离等方法均未能建立起无致病性的二点叶蝉室内种群。 建立二点叶蝉实验种群，以3～5叶龄的玉米为最佳饲养寄主，以小麦等其他禾本科植物为补充饲料，延长饲养寄主的存活时间，对种群的繁殖扩大起重要作用。饲养温度为25±5℃，相对湿度为80±5％、光周期为14L：10D是二点叶蝉生长发育较理想的环境条件。 2 二点叶蝉的生物生态学特性 2．1 二点叶蝉的生物学 二点叶蝉成虫头冠前缘与颜面交接处有1对大而圆的黑斑；若虫腹部末端背面两侧有2个对称的黑色圆斑。若虫共5龄。该虫表现出很强的警觉性、趋光性、趋嫩绿性等特点。二点叶蝉以禾本科植物为食，在四川南充地区玉米生育期间发生3代，以成虫在小麦上越冬，次年4月初开始在玉米幼苗上活动、取食、交配和产卵，各世代均在禾本科植物上完成年生活史。 不同寄主植物对二点叶蝉生长发育和繁殖有明显影响。25℃恒温条件下二点叶蝉在虮子草上不能完成世代发育。取食玉米、小麦、高粱、水稻、小米、大麦6种寄主植物，各虫态的发育历期、存活率、雌成虫寿命及单雌平均产卵量存在显著差异。从卵到若虫期的发育历期在高粱上最短(24.1d)，玉米上次之(24.2d)，小麦上最长(25.5d)；取食水稻时，若虫的 西南农业大学硕十学位论文存活率(40.8%)最低，成虫寿命最短(12.2d)，单雌平均产卵量(123粒)显著低于其它5种寄主植物。用生命表参数综合评价，6种寄土植物中，小米和玉米最适合二点叶蝉生长发育及繁殖，其次分别为高粱、大麦、小麦、水稻。2.2二点叶蝉自然种群动态研究 系统研究了四川省南充市仪陇县二点叶蝉自然种群数量动态和空间分布格局。结果表明，4月上旬至5月上旬，二点叶蝉自然种群数量急剧上升，5月中旬至6月上旬下降。3个不同海拔种群密度有一定的差异，高海拔地区虫口密度最大值达到3.5143头/株，中海拔为3.0114头/株，低海拔仅为1.0343头/株。选择受密度影响较小的负二项分布K值，描述玉米上二点叶蝉自然种群在3个海拔高度上的空间格局及时序动态。在玉米生育期间，二点叶蝉种群即可作聚集分布亦可作均匀分布。4月中下旬，二点叶蝉种群呈均匀分布(K<0);5月份，呈聚集分布(K>0);6月上中旬呈均匀分布(K<0);6月下旬至7月上旬呈聚集分布(K>0)，表现为扩散一聚集~再扩散~再聚集的总趋势。3个海拔间聚集强度有一定的变化，5月份高海拔的K值最小，聚集强度最高;6月下旬至7月上旬低海拔的聚集强度最高。从玉米整个生长发育阶段分析入手，高、中海拔的聚集强度大于低海拔。3二点叶蝉的致病性 用生物学方法测定了二点叶蝉传播玉米鼠耳病的规律及不同玉米品种对玉米鼠耳病的抗性。结果表明，二点叶蝉能够通过卵把致病因子传给子代。雌成虫的致病性比雄成虫强。饲养1小12代后，成虫致病性下降。单头成虫或若虫取食24h，各虫态均能导致玉米发生鼠耳病，其中以4龄若虫的致病性最强，其次是成虫和5龄若虫。个体间致病性有一定差异，4龄若虫取食玉米后，0、一、2、3、4、5级植株分别.1了15.60%，11.300/0. 16.93%，22.93%，27.6一%，12.63%。成虫取食玉米后，虫口数量与病情指数不呈线性相关，单头成虫可导致玉米发生鼠耳病;超过4头琳时，病情并不随虫口数量的增多而加重。最短取食时间10m初便可导致玉米发病，取食时间超过6h时，病情并不随取食时间的延长而加重。成虫致病效率随时间有很大的变化，其中若虫羽化后最初Zd以及14一16d间致病性较强。 玉米发生鼠耳病的温度为15一35℃，最适温度为28一31℃，在最适温度范围内发病率最高，潜育期相应最短。不同玉米品种对玉米鼠耳病的抗性有一定的差异，渝试一18、渝试一19、鑫一2208、农大一1 08、益一2203、念一2207、念一2221、务一22]5这8个玉米品种，其发病率分别为83.33%、95.00%、96.00%、61.96%、100.00%、62.50%、33.33%、80.77%，在品种轰一2221和悉一22巧上玉米鼠耳病的潜育期比其它儿个玉米品种的长。中文摘要4玉米鼠耳病的发生与防治4.1玉米鼠耳病发生动态研究 根据田?更多还原

【Abstract】 Cicadulina bipunctella (Mats), belonging to the order Homoptera, the family Cicadellidae, the subfamily Euscelinae and the genus Cicadulina, is a kind of minute insect on maize with distribution in Sichuan, Chongqing and Guizhou province of china. It damages directly or indirectly maize in field and leads to great economic losses when the population occurs in abundance. Adopting comprehensively the knowledge and theory of population ecology and disease epidemics, by the field investigations and indoor trials, the bio-ecological characteristics and the pathogenicity of C. bipunctella, the seasonal dynamic of maize wallaby ear virus (MWEV) during the period of maize growth were studied systematically. The results are summarized below.1 The establishment of C. bipunctella experimental populationBy the field investigation, indoor trials and identification to the insect species on maize, the results indicated that C. bipunctella is a major vector insect transmitting MWEV, the non-pathogenetic population can’t be established by collecting in field, separating from eggs, ecdysis and rearing individually.The experimental population was established. C. bipunctella, acquiring from the area of MWEV, could be reared on its host plants maize, wheat, millet and perennial grass family (gramineae) weeds, but maize with 5-7 leaves is the best host. Maintaining the host plants to survival long is the key factor to expand the population. The temperature inside range 25~28℃, the relative humidity 80 + 5% and the photoperiod 14L:10D are the suitable environmental factors for the growth and reproduction of C. bipunctella.2 The bio-ecological characteristics of C. bipunctella 2.1 The biological characteristicsC. bipunctella, adapting to gramineous crops and weeds, is a serious insect on maize. The adult has 1 pair big round black spots at the joint of the region of head and face, and the nymph has 2 symmetry black spots at the end of abdomen. There are 5 nymphal instars. The field investigations showed that it undergoes 3 generations during the period of maize in Nanchong Sichuan area, overwinters with adults in wheat and shows such behavior as high alertness, preference of illumination and preference of green leaves. In the early April of the next year, the overwinter adults start action, fetch, copulation and oviposition on maize.The development, survivorship, and fecundity of C. bipunctella reared on corn, wheat, sorghum, rice, millet, and barley were evaluated at 25℃ in laboratory, respectively. The results showed that the insect could develop and reproduce on corn, wheat, sorghum, rice, millet, and barley, except for Leptochloa panacea (Retz.) Ohwi. The development duration, survival rate, longevity and fecundity of C. bipunctella female adults varied significantly when reared on the six hosts. The development duration (24.1d) of the combined immature stage reared on sorghum was the shortest, then on corn (24.2d) and the longest on wheat (25.5d). The survival rate (40.8%) of immature stages, the longevity (12.2d) and oviposition per female (12.3 eggs) of female adults reared on rice were lower than the other five host plants. Based on the life-table parameters, the most suitable host plants for the development and reproduction of C. bipunctella were millet and corn, followed by sorghum, barley, wheat, and rice.2.2 The dynamic of the natural populationSystematic investigations were carried out on the dynamics of natural population of C. bipunctella. The results showed that the population quantity of the insect was obviously increased from the early April to the early May, them decreased till June, and increased again. There is a significant difference about the density on the three elevations, the density of the insect reached 3.5143 per maize in high elevation, 3.0114 per maize in middle elevation, and 1.0343 per maize in low elevation. The K value of negative binomial distribution less affected by density was chosen to describe the spatial and temporal patterns of the natural population of C. bipu更多还原