Effectiveness of the Modification of Sewers to Reduce the Reproduction of Culex pipiens and Aedes albopictus in Barcelona, Spain

Abstract

Mosquitoes breeding in urban sewage infrastructure are both a source of nuisance to the local population and a public health risk, given that biting mosquitoes can transmit pathogenic organisms to humans. The increasing presence of the invasive mosquito species Aedes albopictus in European cities has further exacerbated the problems already caused by native Culex pipiens. We tested the effectiveness of modifications to sewage structures as an alternative to the use of biocides to prevent mosquito breeding. The placing of a layer of concrete at the bottom of sand sewers to prevent water accumulation completely eliminated mosquito reproduction, and so eliminates the need for biocides in modified structures. Sewer modification is thus a valid low-cost alternative for mosquito control.

Keywords: Aedes albopictus; Culex pipiens; integrated mosquito management; invasive Aedes; manipulation of mosquito habitat; mosquito control.

Figure 1

Mean number ± s.e. of BTI treatments applied in control and modified sewers in 2018 (before sewer modification) and in 2020 (after sewer modification).

Figure 2

Sand sewer with accumulated water before the modification (a) and modified sand sewer with its bottom filled with concrete to the level of the base of the discharge pipe (b).