【作者】 闫海燕；

【导师】 魏国树；

【作者基本信息】 河北农业大学 ， 农业昆虫与害虫防治， 2006， 硕士

【摘要】 本文采用光镜、组织解剖学及电生理学方法对多种农田、果园等生态系统的捕食性天敌优势种—龟纹瓢虫的感、趋光机制进行了研究,主要研究结果如下: 1.头正前方观,龟纹瓢虫成虫的复眼外形似半球,且后方稍向内合拢。每个复眼约包括630个小眼。每个小眼是由一套屈光器(一个角膜和一个晶锥)、6至8个小网膜细胞及其特化产生的视杆和基细胞等几部分组成,从解剖学上表明其复眼类型属于并列像眼。此外,晶体周围及小网膜色素细胞内均含有丰富的色素颗粒。 2.小眼整体纵切显示,其上、下段色素颗粒分布相对较多,中段分布较少。明、暗适应状态对小眼的色素颗粒分布有影响,性别对其分布无明显影响。其中,明适应状态下色素颗粒较均匀地分布于视杆两侧上下,暗适应状态时色素颗粒则主要分布在视杆部位的上侧,显示其具有一定的重叠眼性质,初步表明龟纹瓢虫成虫复眼兼具并列像眼和一定的重叠象眼性质;而在相同的明、暗适应状态下其雌、雄成虫复眼的色素颗粒分布间无明显差异。 3.紫外和大部分可见光区的不同波长的单色光刺激均能使龟纹瓢虫成虫复眼产生振幅不等的ERG反应。依据反应的相对光强LogⅠ振幅的大小(峰-峰值),龟纹瓢虫成虫复眼的光谱敏感曲线在340～605nm的波谱范围内表现为3个大小不等的峰,其中主峰位于黄绿光区的562nm处,次峰位于524nm处,且主次峰ERG值相差不是很大,第三峰位于蓝光区的460nm处,表明龟纹瓢虫成虫可能具有1至3种不同的光感受器类型。 4.光强度对龟纹瓢虫成虫复眼ERG值有影响。在一定的光强度范围内,龟纹瓢虫成虫复眼的ERG值随白光刺激光强度的增加而增大,且前期增长较缓慢,后期逐渐呈现快-慢交替的趋势,整体趋势呈现出近“J”型的式样,表明龟纹瓢虫成虫复眼具有相当强的光强度自调节和耐光能力。 5.性别、昼夜节律及暗适应时间长短均对龟纹瓢虫成虫复眼的ERG值有一定影响。白天和夜晚暗适应一定时间,在相同的相对光强度下,雄成虫的ERG值大于雌成虫;暗适应一定时间,在相同的相对光强度下,雌雄成虫的ERG值均为夜晚高于白天;无论是在白天还是在夜晚,雌雄成虫的ERG值均随暗适应时间的延长而增加,并最后达一平台。不同的个体在白天和夜晚,ERG值达到稳定所需时间不同,白天一般需要约120min,夜晚相对短些,一般需要100min左右。这可能和不同个体之间在白天和夜晚复眼内细胞色素颗粒的移动速度不同有关。 6.龟纹瓢虫成虫复眼的ERG波形成分一般由4个部分组成:开光反应、正相电位、持续负电位和闭光反应,但闭光反应较小,不易看见。其中,光强、波长及刺激时程分别对其有不同程度的影响。更多还原

【Abstract】 The mechanism of photosensitivity and phototaxis of the dominant predatory enemies Propylea japonica (Thunberg) in many farmlands and orchards was investigated by means of microscope, histology and electrophysiology. The results are as follows:1 The compound eyes distributed the upside lateral of the head slightly convergent posteriorly. Each compound eye was composed of approximately 630 ommatidia. Each ommatidium consisted of a cornea, a cone, six to eight retinula cells, and a basal cell. The surrounding of the crystalline and the retinular pigment cells contained abundant pigment granules.2 The longitudinal section of the whole rhabdom showed that the pigment granules in the distal and proximal ends were more than those in the intermediate region relatively. In the light-adapted state, the pigment granules distributed in the most regions around the rhabdoms evenly. However, the distribution of the pigment granules was mainly around the distal region of the rhabdoms in the dark-adapted state, indicating that it had some characters of superposition eyes. No differences were observed between the sexes.3 The spectral sensitivity and intensity response from P. japonica were studies by using ERG’s extracellular recording method. The result showed the monochromatic light stimuli with the different wavelengths within U.V. and most visible light region, including the range of 340-360nm, can induce ERG reactions with different amplitudes. According to the size of the amplitude of relative intensity Log I (perk-perk value), there are three different perks in its spectral sensitivity curves, the major perk appearing at 562nm (yellow-green), the second 524nm and the third 460nm (blue) and the major perk value was almost equal to the second, indicating that P. japonica may own two or three types of photoreceptor.4 The intensity could influence the ERG values of the compound eye of P. japonica. The result indicated that within a certain range of intensity, the ERG would augment with the increase of the intensity of the stimuli of white light. The change of the prophase was not evidence, but the anaphase was the current of "quick-slow", so the whole curve appeared the near "J" shape, showing that the compound eye of P. japonica had quite strong abilities of self-adjustment intensity and light-resistant.5 The sexes, intrinsic diurnal rhythm of P. japonica and the dark-adapted time wouldhave some effects on the values of ERG of the compound eye of P. japonica. In the same conditions, the ERG value of the male adult was larger than the female;the ERG value of the adult on night was larger than the one in day;the ERG value would increase with the dark-adapted time and made stability in end. Every ladybird needed the different time to make the value of ERG stabilization, namely it needed about 120 min in day and 100 min on night. This might be relative to the rate of pigment movement in the different unit of the same species in day or on night.6 ERG consisted of four parts in the compound eyes of P. japonica: on light reaction, positive potential, long negative potential and off light reaction, but the off light reaction was very small and was hardly seen. Their size and shape could be influenced by wavelength, light-intensity and stimulation time.更多还原