我国结膜吸吮线虫在中间宿主——变色纵眼果蝇体内发育过程的研究

STUDIES ON THE DEVELOPMENT OF THELAZIA CALLIPAEDA LARVAE IN THE INTERMEDIATE HOST AMIOTA VARIEGATA IN CHINA

以结膜吸吮线虫产在家兔眼分泌物内的初产蚴和解剖雌虫子宫内的幼虫,喂饲实验室繁殖的变色纵眼果蝇进行感染,证明了变色纵眼果蝇可作为我国结膜吸吮线虫的中间宿主。以终宿主眼分泌物中的初产蚴喂饲感染果蝇,结果在感染后第16天,于存活的11只果蝇中,在2只雄蝇的口器和头部检出感染期幼虫9条。用取自雌虫体内的幼虫,平均每蝇5条幼虫的比例喂饲感染608只果蝇,结果检出阳性蝇106只,其感染率为17.4％。并发现幼虫在果蝇体内发育主要侵入雄蝇睾丸外层组织和雌蝇的血腔壁形成“虫泡囊”,幼虫在囊内发育至腊肠蚴蜕1次皮,进入感染前期发育阶段,再行第2次蜕皮,而发育成感染期幼虫。发育速度与外界温度密切相关,当外界温度为26.1—31.8℃,发育到感染期幼虫最早天数需要17天。

The newborn larvae of Thelazia callipaeda were collected from the rabbit's eyes of experimental infected with T. callipaeda adults or from the uteri of the adult worms by dissection. The newborn larvae were fed to labratory-reared Amiota variegata in experimental infection. 11 A. variegata were fed the newborn larvae collected from rabbit's eyes. Of these, 2A, variegata infected with infective larvae of T, callipaeda were found on the 16th day. 106 (17.4%), within 608 A. variegata which were fed the newborn larvae collected from uteri of T. callipadae adults, were successfully parasitized. Development of T. callipaeda larva vas observed in experimentally infected A. variegata. Newborn larvae shed thier sheath in the first day in the stomach of A. variegata, after which they penetrated the alimentary tract and reached the hemocoel of A. variegata. Most of the larvae entered into the testis of male A. variegata and the wall of hemocoel of female. Developing larvae were always found in the capsules located in tissues of A. variegata. The developmental process of T. callipaeda laevae in A. variegata included three successive stages, namely, sausage stage (susage-shaped larva), pre-infective stage and infective stage. There was a molt of cuticle between the two stages. The infective larvae migrated through the hemocoel to the head and proboscis of A. variegata. The growth rate of T. callipaeda larvae was closely related to the seasonal change of temperature. In the body of A. variegata, newborn larva of T. callipaeda required 17 days for developing into the infective stage under the condition of 26.1—31.8℃.