Pandey V S, Ouhelli H, Verhulst A
Division of Tropical Animal Production, Institute of Tropical Medicine, Antwerp, Belgium.
Vet Parasitol. 1992 Mar;41(3-4):285-92. doi: 10.1016/0304-4017(92)90087-p.
During a 24 month period, 198 donkeys were examined for Gasterophilus intestinalis and Gasterophilus nasalis larvae. Gasterophilus intestinalis was found in 97.5% and G. nasalis in 95.5% of donkeys. The third instars (L3) of both species occurred during all months of the year and so did the second instars (L2), except in April (G. nasalis) and May (G. intestinalis). Over 75% of the animals had up to 200 larvae and 1.5% had over 600 larvae. The maximum number of both L2 and L3 larvae found in any animal was 418 G. intestinalis, 433 G. nasalis and 715 of both species combined. The seasonal variation in the numbers and development status of larvae indicated that the period of greatest activity of adult flies of G. intestinalis was from August/September to November, and that of G. nasalis from May to September. Consequently, the L2 larvae in the stomachs were in peak numbers between November and January for G. intestinalis and between July and September for G. nasalis. The L3 larvae of G. intestinalis had peak numbers between December and July, and those of G. nasalis between October and March. During January-March, most of the L2 larvae of G. nasalis were trapped in polypous nodules near the pyloric end of the stomach. It is concluded that the high-risk period for infection is during late spring and autumn, leading to the heavy larval burden of Gasterophilus in the stomach of donkeys during winter.
在24个月的时间里，对198头驴进行了检查，以确定是否感染了肠胃蝇蛆和鼻胃蝇蛆幼虫。在97.5%的驴中发现了肠胃蝇蛆，在95.5%的驴中发现了鼻胃蝇蛆。这两个物种的第三龄幼虫（L3）全年各月均有出现，第二龄幼虫（L2）也是如此，但4月（鼻胃蝇蛆）和5月（肠胃蝇蛆）除外。超过75%的动物体内幼虫数量不超过200条，1.5%的动物体内幼虫数量超过600条。在任何一头动物中发现的L2和L3幼虫的最大数量分别为：肠胃蝇蛆418条、鼻胃蝇蛆433条，两种蝇蛆合计715条。幼虫数量和发育状态的季节性变化表明，肠胃蝇成虫的最活跃时期是8月/9月至11月，鼻胃蝇成虫的最活跃时期是5月至9月。因此，肠胃蝇的L2幼虫在胃中的数量高峰期为11月至1月，鼻胃蝇的L2幼虫数量高峰期为7月至9月。肠胃蝇的L3幼虫数量高峰期为12月至7月，鼻胃蝇的L3幼虫数量高峰期为10月至3月。在1月至3月期间，鼻胃蝇的大多数L2幼虫被困在胃幽门端附近的息肉状结节中。得出的结论是，感染的高危期是在春末和秋末，这导致冬季驴胃中肠胃蝇幼虫负担沉重。
