Departamento de Ecología, Genética y Evolución, and Instituto de Ecología, Genética y Evolución de Buenos Aires (UBA-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, 4to Piso, Laboratorio 54. C1428EHA, Buenos Aires, Argentina.
Departamento de Ecología, Genética y Evolución, and Instituto de Ecología, Genética y Evolución de Buenos Aires (UBA-CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, 4to Piso, Laboratorio 54. C1428EHA, Buenos Aires, Argentina.
Acta Trop. 2024 Jul;255:107222. doi: 10.1016/j.actatropica.2024.107222. Epub 2024 Apr 27.
The "oviposition preference-offspring performance" hypothesis proposes that females lay their eggs in habitats that maximize the fitness of their offspring. The aim of this study was to assess the oviposition site selection by Aedes aegypti females and the success of their larvae in habitats with different detritus accumulation times, under conditions representative of the natural spatial variability of detritus quality and quantity in the Metropolitan Area of Buenos Aires, Argentina. Two experiments were performed, one assessing oviposition site selection and the other analyzing developmental success. In both experiments, two levels of detritus accumulation time were compared, one with short-time detritus accumulation (2 weeks), and the other with long-time detritus accumulation (8 weeks). Naturally fallen detritus was used in both experiments, collected in ten sites across the Metropolitan Area of Buenos Aires. In the oviposition experiment, two contiguous ovitraps corresponding to each accumulation time were placed at each of the ten sites and the number of eggs received for each accumulation time was compared. In the development experiment, always 19 larvae were raised in containers of both accumulation times and overall performance was compared using an integrated index that considers survival, development time and female size. A large variability in the amount of detritus collected at the different sites was observed. The number of eggs was significantly higher in the long-time than in the short-time detritus accumulation containers, and approximately proportional to the amount of detritus in each ovitrap. The performance was not affected by the detritus accumulation time, but a better performance was detected in containers that received a higher amount of organic detritus, regardless of the accumulation time. Leaves were on average the most abundant type of detritus, with an average of 53 % of the total detritus collected. The amount of leaves added 2 weeks before hatching showed a positive effect on larval performance. Our results do not support the "oviposition preference-offspring performance" hypothesis, since Ae. aegypti females laid eggs in containers where larvae did not show a better performance. Moreover, at larval densities related to the number of eggs actually laid in each of the accumulation times, it is expected that the performance would be even worse in the most selected containers, due to the density-dependent effects of crowding. Since the results obtained reflect the natural heterogeneity of the environmental conditions in the region studied, they might be a fairly good indicator of what occurs in natural larval habitats.
“产卵偏好-后代表现”假说提出，雌性会在最有利于后代生存的栖息地产卵。本研究的目的是评估在阿根廷布宜诺斯艾利斯大都市区自然空间变异性条件下，不同碎屑积累时间对埃及伊蚊雌性产卵部位的选择及其幼虫的成功程度。进行了两项实验，一项评估产卵部位选择，另一项分析发育成功。在这两项实验中，比较了两种碎屑积累时间水平，一种是短时间碎屑积累（2 周），另一种是长时间碎屑积累（8 周）。在这两项实验中都使用了自然掉落的碎屑，这些碎屑是在布宜诺斯艾利斯大都市区的 10 个地点收集的。在产卵实验中，每个积累时间的两个连续的诱卵器放置在 10 个地点中的每一个地点，比较每个积累时间收到的卵数。在发育实验中，总是在两个积累时间的容器中饲养 19 条幼虫，并使用综合指数比较整体表现，该指数考虑了存活率、发育时间和雌性大小。在不同地点收集的碎屑量存在很大的差异。在长时间碎屑积累容器中的卵数明显高于短时间碎屑积累容器，且与每个诱卵器中的碎屑量大致成正比。性能不受碎屑积累时间的影响，但在接收更多有机碎屑的容器中检测到更好的性能，而不管积累时间如何。叶子平均是最丰富的碎屑类型，占收集到的碎屑总量的 53%。孵化前 2 周添加的叶子数量对幼虫表现有积极影响。我们的结果不支持“产卵偏好-后代表现”假说，因为埃及伊蚊雌性在幼虫表现不佳的容器中产卵。此外，在与每个积累时间实际产卵数量相关的幼虫密度下，由于拥挤的密度依赖效应，预计在选择最多的容器中，表现会更差。由于获得的结果反映了研究区域环境条件的自然异质性，它们可能是自然幼虫栖息地中发生情况的一个相当好的指标。
