Knox Tessa B, Yen Nguyen Thi, Nam Vu Sinh, Gatton Michelle L, Kay Brian H, Ryan Peter A
Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Brisbane, Australia.
J Med Entomol. 2007 Mar;44(2):192-204. doi: 10.1603/0022-2585(2007)44[192:ceoqsm]2.0.co;2.
In response to an identified paucity of information on the size and composition of immature Aedes aegypti (L.) (Diptera: Culicidae) populations in large field containers, we assessed net sampling and pumping/sieving methods for estimating and enumerating third (III)/fourth (IV) instar and pupal populations. Sweep net detection thresholds (number above which > or = 90% chance of a positive sample) were < or = 28 immatures for seven different container types (115-3000 liter jars and tanks) in the laboratory, and mean recovery percentages varied by container type (6.15-41.29 and 7.39-33.10% for III/IV instars and pupae, respectively). A pumping method or hand bailing was applied in the field for the collection of III/IV instars and pupae from 406 receptacles, of which 343 had been previously sampled via a five-sweep netting technique. Larvae were 9.30 times more prevalent than pupae, and abundance varied by container type with means of 36-537 III/IV instars and 6-53 pupae per receptacle. Sweep netting for III/IV instars effectively identified 86.2% of Ae. aegypti-positive containers, whereas sampling for pupae detected only 43.1% of positive containers. When conversion factors (inverse of laboratory recovery percentages) were applied to field net sampling data, estimates of container populations were more accurate for III/IV instars than pupae (maximum R2 = 0.610 and 0.328, respectively); however, the relationship between immature abundance and emergent adult populations remains to be defined.
鉴于已发现关于大型野外容器中未成熟埃及伊蚊（双翅目：蚊科）种群规模和组成的信息匮乏，我们评估了用于估计和计数三龄/四龄幼虫及蛹种群的网捕法和抽水/筛滤法。在实验室中，对于七种不同类型的容器（115至3000升的罐子和水箱），扫网检测阈值（样本呈阳性概率≥90%时的数量）≤28只未成熟个体，且平均回收率因容器类型而异（三龄/四龄幼虫和蛹的回收率分别为6.15%至41.29%和7.39%至33.10%）。在野外，采用抽水法或手工舀水法从406个容器中采集三龄/四龄幼虫和蛹，其中343个容器此前已通过五次扫网技术进行过采样。幼虫的出现率比蛹高9.30倍，且丰度因容器类型而异，每个容器中三龄/四龄幼虫的平均数量为36至537只，蛹的平均数量为6至53只。对三龄/四龄幼虫进行扫网能有效识别86.2%的埃及伊蚊阳性容器，而对蛹进行采样仅能检测到43.1%的阳性容器。当将换算因子（实验室回收率的倒数）应用于野外网捕采样数据时，对三龄/四龄幼虫的容器种群估计比对蛹更准确（最大R²分别为0.610和0.328）；然而，未成熟个体丰度与羽化出的成虫种群之间的关系仍有待确定。
