【作者】 杜娟；

【导师】 仵均祥；

【作者基本信息】 西北农林科技大学 ， 农业昆虫与害虫防治， 2015， 博士

【摘要】 梨小食心虫是一种世界性的果树害虫,除西藏未见报道外,广布我国各水果产区。寄主植物包括蔷薇科的多种果树,以幼虫取食桃、苹果、梨、李子等的嫩梢和果实。在我国,梨小食心虫春夏季主要危害桃梢,夏秋季转移为害梨果,以桃梨混栽区发生危害最为严重。本研究采用顶空吸附采样和GC-MS方法,收集鉴定桃、梨挥发物的季节性变化;在室内研究了梨小食心虫对部分挥发物的触角电位反应和寄主发育期对梨小食心虫生长表现的影响;在田间调查的基础上,研究了基于性诱剂诱捕器监测的梨小食心虫防治指标。主要研究结果如下:1.采用动态顶空吸附法与GC-MS收集鉴定结果表明,不同季节桃、梨挥发物的种类与含量均不同。桃树上共检测到38种组分,梨树上47种。在所测的样品中,仅在桃树花期未检测到顺-3-己烯乙酸酯,在其他样品中,顺-3-己烯乙酸酯的含量均较高。在所有的样品中都检测到法呢烯,但是不同样品中法呢烯异构体种类及其比例不同。苯甲醛在生长季节前期的桃树上可以检测到,后期降低或检测不到;在梨树上,仅8月中旬可以检测到,这与梨小食心虫于8月大量由桃树转移到梨果上危害的行为相一致。2.梨小食心虫对供试的13种单体化合物的EAG反应结果表明,梨小食心虫的EAG反应与单体化合物的种类、浓度、成虫的性别、雌虫的交配状况有关。梨小食心虫的EAG反应随单体化合物浓度的升高而增加。雄虫对中间浓度(0.01-10μg/μL)顺-3-己烯乙酸酯和低浓度(0.001-10μg/μL)乙酸己酯的EAG反应大于雌虫。雌虫对低浓度水杨酸甲酯(0.001,0.01和0.1μg/μL)、高浓度庚醛(1,10,100μg/μL)、α-蒎烯(1,10,100μg/μL)、所有浓度苯甲醛的EAG反应大于雄虫。4日龄交配雌虫对0.001-1μg/μL苯甲醛的反应显著高于未交配雌虫。在所有供试的单体化合物中,雌、雄虫对α-蒎烯的反应较小。梨小食心虫对顺-3-己烯乙酸酯、乙酸己酯、反-2-己烯醛等绿叶挥发物的反应较高。3.不同季节桃、梨嫩梢和果实对梨小食心虫的发育历期、存活率和繁殖力影响显著。梨小食心虫在桃梢和桃果上发育速度明显快于取食梨梢和梨果的个体。取食桃梢的梨小食心虫羽化前存活率最高,而取食5月10日采集的梨果的梨小食心虫不能存活。初孵幼虫在嫩梢上的钻蛀率明显高于果实,在梨果上的钻蛀率随梨果采摘时间的推迟而升高。取食果实的梨小食心虫蛹重高于取食嫩梢。取食梨梢的雌成虫生殖力显著低于取食其他寄主材料。取食桃梢的净增殖力与内禀增长力均最高,取食梨梢的最低。基于梨小食心虫生命表参数的不同寄主材料的聚类分析表明,试验所用寄主材料可以被分为两类,5月10日采摘的桃果、梨梢、6月15日和7月15日采摘的梨果,不适合梨小食心虫的生长发育;桃梢、6月15日采摘的桃果和8月15日采摘的梨果,适合梨小食心虫的生长发育。4.梨小食心虫在梨果胴部中间产卵量最高。梨小食心虫在早酥梨上的卵果率与百果卵数随梨果直径的增大而增加。卵果率和百果卵量与平均诱蛾量显著相关,呈对数关系。可以将卵果率或百果卵量转化为诱蛾量作为防治指标。当以卵果率1%和百果卵量1粒为防治指标时,基于性诱剂监测的梨小食心虫的防治指标分别为每天每诱捕器2.27和2.32头;以卵果率2%和百果卵量2为防治指标时,则分别为每天每诱捕器2.61和2.58头。更多还原

【Abstract】 The oriental fruit moth, Grapholita molesta, is a globally important insect pest. In China,the moth widely distribute in all of the fruit producing areas except Tibet. The host of the moth includes many fruit trees belong to the family Rosacaae. The larvae infest shoots and fruits of peach, apple, pear, and plum et al. In China, the laevae feed shoots of peach in early growing season, shift to infest to pear fruits at the later growing season, and the companion planting area of fruit trees was the most serious. Volatiles from peach and pear in different season were collected and identified by dynamic headspace absorption method and GC-MS,the EAG responses of the moth to several compound of volatiles and the development and fecundity performance of the moth reared on shoots and fruits of peach and pear in different seasons conducted in laboratory condition, and control index based on number of adults captured by sex pheromone traps was studied based on investigation in field. Main results of this study are as follows.1. Collected and identified volatiles from peach and pear in different season by dynamic headspace absorption method and GC-MS. The results showed that the kinds and contents of the volatile compounds emitted from peach and pear in different season were different. 38 compounds were detected in peach and 47 compounds in pear. Z-3- hexene acetate was detected and the contect was higher in all samples except of volatile emitted from peach twigs with flowers. Farnesene was contected in all of the samples, but different sample contain types and contents of farnesene were different. Benzaldehyde can be detected in peach volatiles of the early growing season, decreased or undetected in later growing season; but in pear volatiles, benzaldehyde can be detected in mid-August. That was consistent with the migratory of the moth.2. Electroantennogram responses of the oriental fruit moth to 13 host volatile compounds were conducted. Results showed that the EAG value of the moth were relate to type and concentration of compound, gender of adult, and the mating status of female. The EAG was increased with the increasing concentration of the compound. The EAG of male to the middle concentration(0.01-10μg/μL) of Z-3-hexene acetate and low concentration(0.001-10μg/μL)of Hexyl acetate were higher than female. The EAG of female to low concentration(0.001,0.01 and 0.1μg/μL) of methylis salicylas, high concentration(1,10,100μg/μL) of heptanal andα-pinene, benzaldehyde were higher than male. The EAG of the 4th day mated female to0.001-1μg/μL benzaldehyde were higher than unmated female. EAG of adult to all concentration of α-pinene were lower. The EAG of the moth to green leaf volatiles, such as Z-3-hexene acetate, hexyl acetate, trans-2-Hexenal were higher.3.The results showed that development time, survivorship, and fecundity of the moth were signicantly different on shoots and fruits of peach and pear under laboratory conditions.The moth developed faster on shoots and fruits of peach, compared with pear. The preimaginal survival rate was the highest on peach shoots while it was found that the moth could not survive on pear fruit collected on 10 of May. The boring rates of neonatal larvae were higher on shoots than on fruits and the rate value presented higher with the longer delay in the collecting time for pear fruits. Pupal weights of female were significantly higher on fruits than those on shoots. Fecundity were significantly less on pear shoots than those on the other host plants collected at different time. The net reproductive rate( R0) and intrinsic rate of natural increase( rm) was highest on peach shoot, and lowest on pear shoot. Cluster analysis of the life table parameters of the moth on shoots and fruits of peach and pear cut at various times of the growing season indicated that peach fruit picked at 10 May, pear shoot,pear fruit picked at 15 June and 15 July were unsuitable host to the pest, and peach shoot,peach fruit picked at 15 June, pear fruit picked at 15 August were suitable host to the peat.Therefore, it is concluded that the switch of the moth from peach orchard to pear orchard related to different performance because different diet that the larvae feed on, and volatile blends emitted by host plant in process of host location.4. Results showed that the number of egg lay on middle of torso of fruit was the highest.Percent of fruit with egg and number of eggs per 100 fruits increased with the increasing of diameter of fruit. Percent of fruit with eggs and number of egg per 100 fruits all were significant correlation with number of moth traped by sex pheromone lure, and the relation was logarithmic. The management threshold based on percent of fruit with eggs or number of egg per 100 fruits could transformate into the the management threshold based on number of moth traped by sex pheromone lure. If taken 1% of fruit with egg and 1 egg per 100 fruits as the management threshold, which was 2.27 and 2.32 based on number of G. molesta traped by sex pheromone lure, respectively. If taken 2% of fruit with egg and 2 eggs per 100 fruits as the management threshold, which was 2.61 and 2.58, respectively.更多还原