Molez J F, Desenfant P, Jacques J R
Institut français de recherche scientifique pour le développement en coopération, Antenne ORSTOM, Port-au-Prince, Haïti.
Bull Soc Pathol Exot. 1998;91(4):334-9.
Hispaniola has the highest malaria rate in the West Indies. A study of the bio-ecology of the major vector Anopheles albimanus was carried out in Haïti. Our observations concerned the length of pre-imaginal stages, biting rates and the gonotrophic cycle. A table of its complete life cycle, stage by stage, was produced as well as a graph illustrating its whole larval development in its natural habitat. Results in the field and insectarium were compared. In the laboratory, the development was shorter, except for pupae. The temperature was the main factor governing the length of pre-imaginal development. Preimaginal development decreased from 15 days in the field to 9 days in the insectarium whereas the temperature was a high of 4 degrees C. The nycthemeral activity and seasonal variations of An. albimanus were studied, by monthly all-night captures on human volunteers, during a full year in exo- and endophilic situations. Two sampling sites were chosen for comparison, An. albimanus were caught at every hour of the nycthemeral cycle, with a peak around midnight. Monthly variations were affected by the rains. The vector was more exophagous, when its density was high. The parity rate of the biting population varied between 85.8% and 20.0%; it was low at the beginning of the rains and increased when the rains stopped and breeding places dried out. To study the gonotrophic cycle of wild An. albimanus, several techniques were used jointly; follicles dissection; follicular relics; length of maturation of follicles. The length of the full cycle and of each of its components was estimated (quest of host for blood meal; maturation phase; breeding site seeking). In Haïti 41 h (nulliparous), or 21 h (parous) were necessary for females to have a complete maturation of the follicles. The lengthening of the gonotrophic cycle of parous An. albimanus, in the natural field site, was estimated to last about 4 days. For nulliparous it was 5 days, and 7 days if a pregravid stage was necessary. Considering the sporogonic cycle of Plasmodium falciparum (12 days), the wild population of An. albimanus females could become infective at the third blood feeding in Haïti.
伊斯帕尼奥拉岛是西印度群岛疟疾发病率最高的地区。在海地开展了一项关于主要病媒白纹伊蚊生物生态学的研究。我们的观察涉及羽化前期的时长、叮咬率和生殖营养周期。制作了其完整生命周期的逐阶段表格，以及一幅说明其在自然栖息地整个幼虫发育过程的图表。对野外和昆虫饲养室的结果进行了比较。在实验室中，除蛹期外，发育时间较短。温度是决定羽化前期发育时长的主要因素。羽化前期发育时间从野外的15天减少到昆虫饲养室的9天，而温度相差4摄氏度。通过在一整年里对处于嗜外和嗜内环境的人类志愿者进行每月整夜捕捉，研究了白纹伊蚊的昼夜活动和季节变化。选择了两个采样点进行比较，在昼夜周期的每个小时都对白纹伊蚊进行捕捉，午夜左右出现一个峰值。每月变化受降雨影响。当病媒密度较高时，其更倾向于在户外叮咬。叮咬种群的产雌率在85.8%至20.0%之间变化；在降雨开始时较低，在降雨停止且繁殖地干涸时增加。为了研究野外白纹伊蚊的生殖营养周期，联合使用了几种技术；卵泡解剖；卵泡遗迹；卵泡成熟时长。估算了整个周期及其每个组成部分的时长（寻找宿主获取血餐；成熟期；寻找繁殖地）。在海地，未产卵雌蚊使卵泡完全成熟需要41小时，已产卵雌蚊则需要21小时。在自然野外环境中，已产卵白纹伊蚊的生殖营养周期延长估计持续约4天。未产卵雌蚊为5天，如果需要孕卵期则为7天。考虑到恶性疟原虫的孢子生殖周期（12天），海地的野外白纹伊蚊雌蚊种群在第三次吸血时可能具有传染性。
