【作者】 罗茜；

【导师】 王鸿斌；

【作者基本信息】 中国林业科学研究院 ， 森林保护学， 2011， 硕士

【摘要】 小蠹科昆虫是重要的森林害虫,它的分类是研究和防治的基础,但是此类昆虫体小种多,给分类鉴定造成一定困难。目前,小蠹科昆虫的分类主要是利用昆虫的外部形态特征、生理学特征和遗传学特征,从声学的角度对小蠹进行分类国内外还未见报道。本研究从声学的角度对红脂大小蠹、华山松大小蠹、云南切梢小蠹、短毛切梢小蠹和横坑切梢小蠹进行了研究,具体从三个方面进行了探索:五种小蠹胁迫声信号在时域和频域上的差异:利用胁迫声信号,结合语音识别的相关技术,对五种小蠹自动识别分类;对采自云南松上的三种切梢小蠹的发声器官做扫描电镜,观察此三种切梢小蠹发生器的位置、形态,并对三种小蠹的发声器做了比较,为进一步确定三种小蠹种间差异提供证据。现得出结论如下:(1)分析五种小蠹胁迫声信号的时域特征和频域特征包括单脉冲数、脉冲组持续时间、主峰频率,结果表明五种小蠹不同属种间差异显著,但是同属内种间差异不明显。(2)本研究利用人工神经网络和摩尔频率倒谱系数(MFCC)对五种小蠹进行声学识别分类,最高识别率达到100%,平均识别率为88.8%,识别效果较高,为小蠹的分类提供了一个更加便捷的方法。利用线性预测倒谱系数(LPCC)作对照,平均识别率为76.4%,识别性能比MFCC差,这与人类语音识别中的结果一致。(3)云南切梢小蠹、短毛切梢小蠹和横坑切梢小蠹三种切梢小蠹的音锉由脊状横纹组成,三种小蠹音锉结构差异不大。三种小蠹的左右翅差异较大,主要表现在右翅音锉与翅锁结构之间有一鳞片状结构区域,左翅无此结构。左翅的横纹相较于右翅更加密集、深刻。因此推断发声主要在左翅,右翅不发声或只起辅助作用。三种切梢小蠹的音锉在雌雄虫之间也略有差异——雄虫的音锉密集,深刻,而雌虫相对较疏松、平坦。(4)三种切梢小蠹的刮器由锥形突起构成。刮器雌雄虫之间差别不大,但是这三种小蠹种间差异较大:云南切梢小蠹的刮器是由1排锥形突起构成,没有重叠;短毛切梢小蠹由1-2排刺状突起构成,中间多重叠成2排;横坑切梢小蠹刮器排列较为不规律,一般由2-3排刺状突起构成。三种小蠹刮器的差异可作为其分类的依据。更多还原

【Abstract】 Bark beetles in Scolytidae are the very important forest pests, classification of which is the basic of research and prevention. However, the bark beetles, distributed in many species, are small and some are familiar in appearance, which makes the classification difficult. So far the methods of classification of bark beetles are mainly made use of the features of appearance, physiology and genetics but the bioacoustics classification has not been reported. This paper shows the research on the bioacoustics of Dendroctonus valens, Dendroctonus armandi, Tomicus yunnanensis,Tomicus brevipilosus and Tomicus minor specially including three aspects: find the differences of stress stridulation of five bark beetle species in time and frequency domain; research into the automated identification of the five bark beetles by bioacoustics on the basis of the related techniques of speech recognition; describe and compare the location and appearance of stridulatory organs of Tomicus yunnanensis,Tomicus brevipilosus and Tomicus minor and prove the interspecific differences further by SEM. The results are as following:(1) Analyze time-domain including number of pulse groups and lasting time of pulse groups as well as frequency-domain including main peak frequency of five bark beetle species. The result was that the differences between the species in the different genus were obvious, whereas the differences between the species in the same genus were indistinctive.(2) The automated identification and classification system based on ANN and MFCC worked well, which the highest identification rates were 100% and the average identification rate was 88.8%, supplying a more convenient method to classification and identification of bark beetles. The results showed that identification rates of LPCC as a control were obviously lower than that of MFCC, just like the results in speech recognition.(3) The files of three Tomicus beetles from Yunnan were familiar and consisted of parallel ribs. The files on the right and left elytra had discrepancies, which were especially embodied in there being a area consisted of squamae between the file and the sutural on the right elytra but not on the left elytra, which resulted in the length of ribs on the left longer than that on the right. Otherwise, the ribs of the left elytral file were more intensive and deeper than those of the right elytral file. Thus, it was deduced that in the stridulatory process the left file took the main role and the right one was accessory. The ribs of male file were more intensive and deeper than those of female file.(4) The plectrums of three Tomicus beetles were consisted of numerous small cone-like structures. There were few differences between male and female beetles. Interspecific difference between the three species was remarkable: the plectrum of T. yunnanensis was consisted of one row of cone-like structures; the plectrum of T. brevipilosus was consisted of one to two rows of cone-like structures, usually two rows at the middle; the plectrum of T. minor, consisted of two to three rows of cone-like structures, was more unorderly. The difference can be another evidence to classify the three species.更多还原