摘要
本文研究了荷兰两南部莱茵河和默兹河三角洲地区五斑按蚊(Anopheles maculipennis)复合体蚊虫的分布及生态学。研究地区以前曾流行过疟疾,而黑小按蚊(A.atroparvus)则是唯一的传病媒介。对五斑按蚊的125处潜在的水生生境进行了采样,其中有47处(37.6%)含有这一物种复合体的幼体。幼虫密度为每平方米7.4～325.93个幼体。水中的氯度(‰)与幼虫的存在和/或密度之间无相关性。五(王又王)按蚊的存在与某一特定水生植物生境无关,尽管幼虫往往是与浮游藻类(浒苔属)一起被发现的。在经历过涨潮淹没的区域没有发现有幼虫。一种新开发的PCR方法被用来鉴别蚊子的两似种。在研究过的150种幼虫中,只有4种被确定为黑小按蚊,其他的均为五班按蚊麦赛变种。成年蚊虫确定为五班按麦变种,30种野外捕获的蚊子以叮食家禽为生。鉴于1999年发现的大多数按蚊为五班按蚊麦赛变种,因此可以断定自以前1935年开展的按蚊调查以来,研究地区曾经历过一次急剧的生态变化,从而造成黑小按蚊几近灭绝。这一物种是荷兰唯一的一种疟疾传病媒介,因此估计在荷兰的沿海地区疟疾会恢复到以前的地方性流行状态。
The distribution and ecology of mosquitoes of the Anopheles maculipennis complex were studied in the delta of the rivers Rhine and Meuse in the southwest of The Netherlands. The study area was previously malarious, with A. atroparvus being the only vector. 125 potential aquatic habitats of A. maculipennis were sampled, of which 47 (37.6%) contained larvae of this species complex. Larval densities varied from 7.4–325.93 larvae m^-2. There was no correlation between chlorinity (‰) of the water and presence and/or density of larvae. The presence of A. maculipennis was not associated with one particular aquatic floristic habitat, although larvae were often found together with floating algae (Enteromorpha spp.). Larvae were not found in areas experiencing tidal flooding. A newly developed PCR method was used for identification of the mosquito sibling species. Of 150 larvae examined, only 4 were identified as A. atroparvus. All other larvae examined were A. messeae. Adult mosquitoes were identified as A. messeae and 30 wild-caught mosquitoes had fed on domestic animals. Because most anophelines found in 1999 were A. messeae, it is concluded that the study area has undergone a dramatic ecological change since the previous anopheline investigations in 1935, causing the near extinction of A. atroparvus. This species was the only malaria vector in The Netherlands and therefore it is not expected that malaria can return to its former endemic status in the coastal areas of The Netherlands.
