目的 利用石蜡切片技术对荒川库蠓成虫内部结构组织学进行研究。 方法 采集荒川库蠓成虫,制作永久玻片后进行形态鉴定,将标本的翅和足解下后,其余部分在Duboscq-Brasil固定液中固定,逐级脱水、二甲苯透明、石蜡包埋、连续切片以及苏木素-伊红染色后,对切片进行脱水、透明、中性树胶封片处理,光学显微镜下观察荒川库蠓组织结构。 结果 对荒川库蠓成虫消化系统、神经系统、呼吸系统和生殖系统等内部组织结构的观察结果显示,消化系统由消化道和消化腺2部分组成,消化道又可分为前肠、中肠及后肠,中肠是消化道最发达的部分;消化腺分为左右2个腺体,均包括主腺和附腺,主腺具有分泌作用,附腺是分泌物的蓄积场所。中枢神经系统由脑和腹神经索2部分组成。脑分为前脑、中脑和后脑,其中前脑发出视神经与复眼相连;中脑发出神经至触角;后脑发出围食道神经与咽下神经节相连。腹神经索包含1个咽下神经节、3个胸神经节和5个腹神经节。呼吸系统主要包括气门、气囊等。气门2对,分别位于中胸和后胸。气囊主要包括背支囊和腹支囊,呈管状或泡状,着色不明显。生殖系统主要包括雌性和雄性内生殖器官。雌性内生殖器官包括1对卵巢、1对输卵管、1个受精囊和1对生殖附腺,雄性内生殖器官包括1对精巢、1对输精管、1根射精管以及1对生殖附腺。结论 荒川库蠓的内部结构组成与其他双翅目昆虫相似,但各系统器官的数量、大小和形态等存在明显差异。

Objective To study the internal structure of adult Culicoides arakawaei by using the paraffin sectioning technique. Methods C. arakawaei adults were collected, fixed and mounted on slides for morphological identification. The wings and feet of the specimens were detached, and the rest part was processed in Duboscq-Brasil fixative solution for fixation, followed by sequential dehydration, transparenting with xylene, embedding in paraffin, serial sectioning; after stained with hematoxylin-eosin (HE), the midge slices were further dehydrated, transparentized and sealed with neutral gum for morphological observation on the tissue structure by light microscopy. Results Observation on the tissue structure of digestive system, nervous system, respiratory system, and reproductive system of adult C. arakawaei the digestive system is composed of a digestive duct and digestive glands, while the digestive duct comprises foregut, midgut and hindgut, with the midgut being the most developed part; the digestive gland consists of two glands on the left and right sides, including primary and accessory gland. The primary gland functions secretion and the accessory gland deposits the secreta. The central nervous system is composed of the brain and the ventral nerve cord. The brain consists of protocerebrum, deutocerebrum and tritocerebrum. The protocerebrum projects, optic nerve to connect the compound eye; the deutocerebrum extends nerves to the antennae; the periesophageal nerve arises from the tritocerebrum to connect, the subpharyngeal ganglion. The ventral nerve cord contains one subpharyngeal ganglion, three thoracic ganglia and five abdominal ganglia. The respiratory system mainly includes valves and air sacs. The chest of C. arakawaei has two pairs of valves, which are located in the middle and posterior part of chest. The sac mainly includes dorsal and ventral parts, which shaped as tubular or froth form, with weak staining signal. The reproductive system is composed of the female and male internal reproductive organs. The female internal reproductive organs include a pair of ovaries, a pair of oviduct, a spermatheca and a pair of accessory reproductive glands. The male internal reproductive organs include a pair of testes, a pair of spermaduct, an ejaculatory duct and a pair of accessory reproductive glands. Conclusion The internal structure of C. arakawaei is similar to that of other Diptera insects, but significantly different in number, size and morphology of organs in each system.