【作者】 张翔；

【导师】 侯有明；

【作者基本信息】 福建农林大学 ， 农业昆虫与害虫防治， 2015， 博士

【摘要】 水椰八角铁甲Octodonta nipae (Maulik)是一种对经济棕榈产业,园林种植,城市美化以及生态安全等方面都具有严重危害的危险性林业害虫。该虫原产于马来西亚,寄主范围包括多种经济类和观赏性棕榈科植物,已入侵等我国南方多个地区,并造成严重的经济损失。福建省自2007年在福清市发现水椰八角铁甲以来,在泉州、厦门、漳州等地区也陆续发现该害虫。水椰八角铁甲具有为害部位隐蔽,难以进行药物防治的特点,不仅如此,该虫还具备成熟前期较短,寿命较长,世代重叠严重,高度聚集,几乎终生都可交配繁殖的生物学特性,使得水椰八角铁甲可以获得更有利的多次交配的条件,因而具备种群快速增长、蔓延扩张迅速以及环境适应性强等优势,一旦入侵新的地区,便很容易定殖。目前,对水椰八角铁甲的主要研究内容包括水椰八角铁甲的生物学特性,适生环境、寄主,生命表研究,寄生性天敌,免疫权衡等。本文主要对水椰八角铁甲交配行为与节律,多次交配对雌虫生殖发育、繁殖力和繁殖适合度的影响,以及子代生存适合度和基因分化等方面进行分析,探讨水椰八角铁甲成虫多次交配的适应性及其影响机制,以期为揭示其繁殖适应性提供理论依据。主要研究结果如下：(1)用行为观察仪,在人工气候室内对水椰八角铁甲的交配行为进行24小时不间断记录,观察和统计该虫的交配行为和交配节律,分析交配行为过程,每天交配的昼夜节律以及交配次数,时长和成功率等的差异。通过实验发现,水椰八角铁甲的主要交配行为包括：接近、触角拍击、爬跨的求偶行为,就位、外生殖器插入、转身锁节、最后离开等一系列交配步骤。同时还发现,交配行为在任何阶段都有可能终止,而部分交配不经过转身锁节这一行为也可以完成交配。每天的11：00-17：00为交配高峰期,峰值出现在13：00前后,交配比例为10.5±1.2%,23：00-7：00交配比例最低。水椰八角铁甲平均每天可以交配12.6±0.7次,光周期处理下水椰八角铁甲的求偶次数(14.4±1.1次),交配次数(9.3±0.5次)以及交配成功率(69.4±3.5%)均显著高于暗周期。而在交配行为中,雄虫有进行转身锁节的交配时长平均为22.52±1.64分钟,显著高于没有进行转身锁节的交配过程；暗周期的锁节行为显著长于光周期。交配时间在10分钟以下的约占所有交配的60.6%,而最长的交配时间可以超过200分钟。雄虫延长交配时间可能为了提高对雌虫的占有率。(2)解剖并观察水椰八角铁甲雌成虫的生殖系统,并对雌虫卵巢的发育程度进行分级,并对其发育初期阶段卵巢结构的大小进行分析,研究多次交配的不同层次对雌虫生殖系统发育产生的影响。水椰八角铁甲的雌虫卵巢发育进度分为5个等级,分别为卵未形成期、卵黄形成期、卵粒可辨期、成熟待产期和持续产卵期。卵未形成期刚羽化雌虫的卵巢形态最小,而在卵黄形成期,卵巢管无论在长度或是面积上都没有明显差异,卵黄的形成只是增加了卵巢管的宽度。而第9日龄之后,由于卵粒的形成,卵巢管的长度,宽度和面积在第12和第15日龄都有较显著的提升。在卵巢发育成熟前只交配1次的雌虫与未进行交配的雌虫第15日龄的宽度和面积无明显差异,只有长度有显著差异,而交配4次的雌虫在15日龄的卵巢长度,面积和面积都比未交配和交配一次的雌虫显著提高；卵巢发育成熟前总交配时间在10分钟以下的雌虫与未进行交配的雌虫只在卵巢长度上有显著差异,而交配10-20分钟和20分钟以上的雌虫之间在15日龄的卵巢长度,宽度和面积没有差异,但其卵巢长度都比未交配的雌虫和交配10分钟以下的雌虫显著提高通过通径系数分析发现,与交配持续时间相比,交配次数对雌虫卵巢管面积的直接影响占主导因素。(3)在48小时内,设置1次、5次、10次、15次、20次交配频率处理组,对不同交配次数的雌虫的产卵前期、产卵量和子代孵化率、性比等进行统计分析。实验表明,不同交配次数处理下,雌虫的繁殖力随着交配频次的升高而提高,次交配处理组的雌虫产卵前期时间最长,为19.8±5.1天,产卵量最少,而15次交配处理组最短,平均为5.0±0.2天,产卵量和卵孵化率最高,平均分别为129.2±5.6枚和79.78±7.45%；而交配20次处理组的雌虫产卵量和卵的孵化率比15次处理组显著性下降。交配频率对水椰八角铁甲的雌雄成虫的寿命都产生了显著性影响,10次交配处理组的雌虫寿命最高,为232.8±21.2天,而15次和20次交配处理组又随着交配频率的上升而迅速下降,20次交配处理组的雌虫寿命最短,为142.1±16.8天,除了1次交配处理组,雌虫的寿命都比雄虫的高,而雄虫的寿命随着交配频率的升高而显著下降；多次交配处理组的子代雌性成虫体重显著增加：水椰八角铁甲的种群发育指数随着交配频率的上升而升高,从最低1次交配处理组的1.84上升到15次交配处理组的25.77。实验结果表明,在水椰八角铁甲的多次交配中,存在雌虫对交配成本和交配受益的资源分配权衡。(4)采用分子生物学方法,设计出水椰八角铁的快速鉴定途径,更成功鉴定了漳州发现的体色不同的叶甲科害虫种群为水椰八角铁甲。通过SSR多态性位点的引物筛选与STR分型分析方法检测不同雄虫多次交配处理下,雌虫后代的基因多样性与父权值分布。实验结果表明,从已获得的微卫星位点中筛选出5对较容易辨别的位点。从各处理组样本微卫星位点的STR分型分析数据来看,与四只不同雄虫交配的雌虫后代产生了明显的基因分化,共享矩阵值较小,0.64±2.8。雌虫与雄虫1次交配后再与另一只雄虫交配3次著低于处理组只交配一次的雌虫,但分化程度小于和四只雄虫交配的雌虫。雌虫与雄虫1次交配后再与另一只雄虫交配3次其父权值较高,为97±1.5%,显著高于相反交配顺序的雌虫。而与四只雄虫交配的雌虫后代的父权值最低,为79±4.1%,显著低于其他处理组。实验表明,雌虫通过多次交配使后代获得更多的基因多样性,而雄性则通过多次交配来提高延续自身遗传基因的概率,与有性经历的雌虫进行重复交配可以巩固自身的父权。更多还原

【Abstract】 Octodonta nipae (Maulik) is one of the most damaging pests of palm tree, which poses a great threat to palm plants industry, economic palm planting, city landscaping and ecological safety. Originating in Malaysia, O. nipae has invaded to several areas in south China and caused a great economic loss. Since first found in Fujian province in 2007, it has spread across the cities of Fuqing, Quanzhou, Xiamen and Zhangzhou. The host ranges of O. nipae include many economic and/or ornamental palm plants, and injures from O. nipae are mainly in the heart young leaves, which is difficult for detection and application of chemical control. In addition, O. nipae has a short generation period but long life time, with the bionomics of severe overlapping generations, high degree of aggregation and almost lifetime breeding, which advantage for multiple mating and polygynandry. Therefore, once invades into a new area, O. nipae is able to spread widely with rapid population growth and acclimatize the environment soon for colonization.So far, the studies of O. nipae have been focused on biological characteristics, suitable environment and host selection, life tables, parasitoids, immunity trade off, etc. This paper aims in investigating mating behavior and copulation rhythm of O. nipae, the efficiencies of multiple mating on reproduction development, fecundity and reproductive fitness of female, as well as survival fitness and genetic divergence of filial generation. The adaption and mechanism of multiple mating in O. nipae will be analyzed, in the hope of providing theoretical basis for reproduction adaptability. The principal results are as follows:1) Aims to determine the mating behavior and copulation rhythms of O. nipae, a video recording system was used to record the mating behavior and copulation events of O. nipae. The results showed that a full process of copulation in O. nipae mainly includes approach, contaction and antennation, mounting, aedeagus insertion, turning around, mating posture, genital interlocking, separation and leaving. Copulation behavior could be observed all day long and was affected by light, with a higher mating rate from 11:00 to 17:00 and a peak in 13:00. The mating frequency in average is 12.6±0.7 per day, and the frequencies of courtship, copulation and mating success in photophases are obviously higher than those in scotophases. The duration of copulation with behavior of genital interlocking is obviously longer than those directly end in mating posture, and the duration of genital interlocking in scotophases are obviously longer than those in photophases. The duration in 60.6% copulation is less than 10 min, however, the longest duration is beyond 200 min. It is supposed that the male prolong the duration in order to increase occupancy with female.2) Laboratory observations on the reproductive system progress of ovarian development and efficiency of multiple mating on the development of ovarian before sexual mature in female of O. nipae were carried out in this experiment. The internal reproductive system of adult female contains panoistic ovaries, lateral and median oviduct, spermatheca and genital chamber. Each ovary of two consists of five ovarioles. Based on the morphological characteristics of ovaries, the development of ovarian can be classified into five stages, which are named nooocyte stage, vitellus forming stage, egg visible stage, egg maturation stage and sustainable ovipositing stage. The shape of ovarian in nooocyte stage is the smallest. In vitellus forming stage, there is not obvious difference in length or area of ovariole in average, only the width enlarges as vitellus forming. Ovarian grow rapidly in egg visible stage, which is obviously larger than before. No obvious difference is found in the width of ovarioles between females mating zero time or once, while ovarioles in females mating four times are obviously great in length, width and area than that of zero and one time. Only the length of ovarioles in females mating within 10 min is obviously great than female not mate, while no obvious difference is found in ovarioles between females mating in 10-20 min and beyond 20 min. To the growth of ovarioles, the path coefficient in mating number is greater than copulation duration.3) The impact of increased mating rate on reproductive fitness of the invasive nipa palm hispid beetle O. nipae is investigated. A series of mating frequencies (i.e.1, 5,10,15,20 times) is selected from video frame playback, ranking from the minimum to maximum mating rate observed under laboratory conditions over a given time period. Fecundity parameters such as life time egg production, egg-hatching rate, effective oviposition period and longevity are investigated for the evaluation of reproductive efficiency. For female O. nipae, increased fecundity is correlated with the mating frequency. Females mating 15 times lay the largest number of eggs (138.8 ±6.9) and have a hatching rate of 47.43±4.08%. After mating 20 times, females suffer significant declines in oviposition (90.3±8.4 eggs) and egg-hatching rate (34.16+4.93%). Moreover, the population growth rate reaches a maximum in the females that mate 15 times. The results show that multiple matings in O. nipae have an intermediate optimal range within which female reproductive success is enhanced, providing empirical evidence for the existence of a trade-off between costs and benefits during copulation based on resource allocation.4) Based on the first internal transcribed spacer (ITS-1) and the mitochondrial cytochrome oxidase I (COI) gene, a diagnostic technique was designed to quickly identify O. nipae. And furthermore, it paves the way for the subsequent experiment about polygynandry of O. nipae populations in different body color. SSR primers were tested randomly for polymorphism, and 9 loci of them were polymorphic.Their polymorphic information content is between 0.062 and 0.582 which shows medium polymorphic. Among different treatment, the offspring of female which mate with four different male has obvious gene differentiation, with the lowest ASM (allele sharing matrix) value in 0.64±2.80. The ASM of female which mate once and men mate triple time with another male is lower than which only mate once, while higher than that mate with four different males. The paternity index in offspring of female which mate once and then mate triple time with another male was the highest, which is 97.0±1.5% and obviously higher than that mate in reverse order. While the paternity index in offspring of female which mate with four different male was the lowest, within 79.0±4.1%. The results showeed that filial generation acquired a higher genetic diversity through female parent’s multiple mating; male enhanced the probability for filial generation to inherit its own genetic gene, and enhanced its paternity through repeated mating with a same non-virgin female.更多还原