Okoye P N, Brooke B D, Hunt R H, Coetzee M
Vector Control Reference Unit, National Institute for Communicable Diseases, NHLS, Sandringham, South Africa.
Bull Entomol Res. 2007 Dec;97(6):599-605. doi: 10.1017/S0007485307005317.
The effect of pyrethroid resistance on the fitness of a laboratory strain of Anopheles funestus originating from southern Mozambique was evaluated by comparing the developmental and reproductive characteristics of a pyrethroid resistant strain with an insecticide susceptible strain. Fitness was evaluated in terms of fecundity, fertility, egg production, developmental time and life stage progression and survival. Of the eggs laid by females of the resistant strain, 81.5% hatched while only 66.9% were recorded in the susceptible strain. The time from egg hatch to adult emergence was longer for the resistant strain (15.9 days) than the susceptible strain (15.2 days). A significantly higher proportion of eggs from the resistant strain (61.6%) survived to adulthood compared with those of the susceptible strain (49%). Fecundity and larval and pupal survival did not differ significantly between strains. Of spermathecae dissected from females of the resistant strain, 56.8% were fertilized compared to 52.6% from the susceptible strain. The proportion of females that successfully produced eggs was 43.3% and 23.3% for the resistant and susceptible strains respectively. Complete failure of larval hatch was recorded in 28.6% of susceptible strain families compared to 7.7% of resistant families. Our results show that pyrethroid resistance in southern African An. funestus does not incur any loss of fitness under laboratory conditions. These results suggest that the removal of pyrethroid insecticide selection pressure may not lead to a regression of resistance alleles in pyrethroid resistant An. funestus populations in southern Africa.
通过比较拟除虫菊酯抗性品系和杀虫剂敏感品系的发育及生殖特征，评估了拟除虫菊酯抗性对源自莫桑比克南部的实验室品系的致倦库蚊适合度的影响。从繁殖力、生育力、产卵量、发育时间、生命阶段进展和存活率方面评估适合度。抗性品系雌蚊所产的卵中，81.5%孵化，而敏感品系中只有66.9%的卵孵化。抗性品系从卵孵化到成虫羽化的时间（15.9天）比敏感品系（15.2天）长。与敏感品系（49%）相比，抗性品系中显著更高比例的卵（61.6%）存活至成年。品系间的繁殖力以及幼虫和蛹的存活率没有显著差异。解剖抗性品系雌蚊的受精囊，56.8%已受精，而敏感品系为52.6%。抗性品系和敏感品系成功产卵的雌蚊比例分别为43.3%和23.3%。敏感品系28.6%的家系记录到幼虫完全不孵化，而抗性家系为7.7%。我们的结果表明，在实验室条件下，南部非洲致倦库蚊的拟除虫菊酯抗性不会导致适合度的任何损失。这些结果表明，去除拟除虫菊酯杀虫剂选择压力可能不会导致南部非洲拟除虫菊酯抗性致倦库蚊种群中抗性等位基因的消退。
