ICMR-National Institute of Malaria Research, New Delhi, India.
J Vector Borne Dis. 2019 Oct-Dec;56(4):303-307. doi: 10.4103/0972-9062.302032.
BACKGROUND & OBJECTIVES: Interspecific competition occurs between members of two or more different species and can often have an influence on mosquito populations. Both Aedes aegypti and Anopheles stepehensi are container breeding mosquitoes and co-exist which may result in larval competition. In this study, interspecific competition between the above two species has been monitored under the laboratory conditions.
Three sets of experiments were conducted with different stages of Ae. aegypti and An. stephensi larvae. First two experiments were set up with I/II instar and III/IV instar larvae of Ae. aegypti and An. stephensi respectively in the ratios of 20:20, 20:40 and 40:20 in plastic bowls. For third set of experiment 20 IV instar larvae of Ae. aegypti were put with equal number of I instar larvae of An. stephensi.
In the presence of food, 12.5-15 % mortality was recorded in I/II stage larvae of Ae. aegypti while in An. stephensi mortality ranged from 21-55%. Pupation commenced from Day 6 onwards in Ae. aegypti while in An. stephensi it commenced from Day 11 onwards. In the absence of food, there was no pupation in both the species but Ae. aegypti survived up to longer duration (7.5-18.5 days with 50% mortality) in comparison to An. stephensi (2-7 days with 50% mortality). When younger stages of An. stephensi (I/II) were put together with older stages of Ae. aegypti (III/IV) in the presence of food, pupation was completed in 85% Ae. aegypti population while there was 100% mortality in An. stephensi population.
INTERPRETATION & CONCLUSION: The better survival and development of Ae. aegypti than An. stephensi under the same conditions exhibits interspecies competition showing competitive advantage of Ae. aegypti over An. stephensi. Further research is required to have a thorough understanding of the interaction between these two container inhabiting mosquito species in the nature.
种间竞争发生在两个或更多不同物种的成员之间，通常会对蚊子种群产生影响。埃及伊蚊和致倦库蚊都是容器滋生的蚊子，它们共同存在，这可能导致幼虫竞争。在这项研究中，在实验室条件下监测了这两种蚊子之间的种间竞争。
用不同发育阶段的埃及伊蚊和致倦库蚊幼虫进行了三组实验。前两个实验分别用埃及伊蚊和致倦库蚊的 I/II 龄和 III/IV 龄幼虫以 20:20、20:40 和 40:20 的比例在塑料碗中设置。第三组实验中，将 20 只 IV 龄埃及伊蚊幼虫与等量的致倦库蚊 I 龄幼虫一起放入。
在有食物的情况下，埃及伊蚊 I/II 龄幼虫的死亡率为 12.5-15%，而致倦库蚊的死亡率为 21-55%。埃及伊蚊从第 6 天开始化蛹，而致倦库蚊从第 11 天开始化蛹。在没有食物的情况下，两种蚊子都没有化蛹，但埃及伊蚊的存活时间更长（有 50%死亡率的情况下为 7.5-18.5 天），而致倦库蚊的存活时间更短（有 50%死亡率的情况下为 2-7 天）。当较年轻的致倦库蚊（I/II）龄与较老的埃及伊蚊（III/IV）龄在有食物的情况下一起放置时，85%的埃及伊蚊种群完成了化蛹，而致倦库蚊种群的死亡率为 100%。
在相同条件下，埃及伊蚊比致倦库蚊的生存和发育更好，这表明种间竞争存在，埃及伊蚊对致倦库蚊具有竞争优势。需要进一步的研究来深入了解这两种容器滋生的蚊子在自然界中的相互作用。
