葱蝇非滞育、 冬滞育和夏滞育蛹发育和形态特征比较

昆虫非滞育、 冬滞育和夏滞育蛹具有不同的生理和发育过程。本研究以葱蝇Delia antiqua作为模式种， 以黑腹果蝇Drosophila melanogaster蛹的发育形态特征和命名为参照， 用解剖、 拍照、 长度测量和图像处理等方法系统地比较研究了非滞育、 冬滞育和夏滞育蛹的发育历期和形态变化， 重点在头外翻和滞育相关发育和形态特征， 目的在于弄清非滞育、 冬滞育和夏滞育蛹发育和形态特征差异， 为滞育发育阶段的识别、 滞育分子机理研究奠定形态学基础。冬滞育蛹的滞育前期、 滞育期和滞育后期分别为4， 85和27 d， 夏滞育蛹的滞育前期、 滞育期和滞育后期分别为2， 8和22 d。从化蛹至头外翻完成为滞育前期, 头外翻完成约10 h内复眼中央游离脂肪体可见。头外翻的完成是滞育发生的前提， 非滞育、 夏滞育和冬滞育蛹头外翻发生在化蛹后的48， 36和83 h， 在头外翻过程中发育形态没有差异。头外翻的过程为： 首先， 头囊和胸部附肢从胸腔外翻， 头部形态出现； 然后， 腹部肌肉继续收缩， 将血淋巴和脂肪体推进头部及胸部附肢。葱蝇蛹在完成蛹期有效积温约15%时进入冬滞育或夏滞育。在滞育期， 蛹的形态一直停留在复眼中央游离脂肪体可见这一形态时期， 且冬滞育和夏滞育的蛹在形态上没有区别。在体长、 体宽和体重上， 冬滞育蛹最大， 夏滞育蛹次之， 非滞育蛹最小。在滞育后期， 在黄色体出现期间， 非滞育蛹的马氏管清楚可见， 呈绿色， 而滞育蛹的马氏管几乎不可见。本研究为认知昆虫滞育生理、 从发育历期和形态上推断滞育发育进程提供了依据。

Comparison of the developmental and morphological characteristics of non-, winter- and summer-diapausing pupae of the onion maggot, Delia antiqua ( Diptera : Anthomyiidae)

The non-diapausing (ND), winter-diapausing (WD) and summer-diapausing (SD) pupae have distinguishable physiological and developmental process. In the present study, the developmental duration and morphological changes of ND, WD and SD pupae were comparatively investigated with the onion maggot Delia antiqua as the model species through anatomic and photographed observation and measurement, with emphasis on the head evagination- and diapause-related characteristics. The study aims to understand the differences of developmental and morphological characteristics of ND, WD and SD pupae, and lays a morphological base for the distinguishment of diapause developmental stage and study of diapause molecular mechanism. The developmental durations of pre-diapause, diapause and post-diapause of WD pupae were 4, 85 and 27 d, respectively, while those for SD pupae were 2, 8 and 22 d, respectively. The pre-diapause begins at the pupation stage, and ends when the free fat body appears in the central area of eyes, which happens 10 h after the completion of head evagination. The completion of head evagination is the premise of diapause occurrence, the head evagination of ND, SD and WD pupae happened at 48, 36 and 83 h after pupation, and there was no morphological difference observed in the developmental process of head evagination between these three kinds of pupae. During the process of head evagination, firstly, the head capsule and thoracic appendages turned out from thorax capsule, and the head got to the location and shape of matured pupae; then, the abdominal muscles continued contraction to push the haemolymph and fat body into the head capsule and thoracic appendages. The pupae entered SD and WD when approximate 15% total effective accumulated temperature was obtained at the pupal stage. In the duration of diapause, the pupal morphology remained in the form of the appearance of free fat body in the central area of eyes, and no difference was observed between these two kinds of diapausing pupae in morphology in the diapause stage. The WD pupae had the largest body length, width and weight, followed by SD pupae and then ND pupae. At the post-diapause stage, malpighian tubules of ND pupae were green and clearly visible during the existence of the yellow body, whereas they were almost invisible in the diapausing pupae. This study provides basic data for understanding diapause physiology and inferring diapause development process of insects through developmental duration and morphology.