Temporal Activity and Distribution of the Invasive Mosquitoes Aedes albopictus and Aedes japonicus in the Zagreb Area, Croatia.

Abstract

Aedes albopictus and Aedes japonicus are invasive mosquito species that are causing great public concern. Aedes albopictus have successfully spread in Croatia, established in both the coastal and continental parts of the country, while Aedes japonicus is invading temperate climate areas. The invasive Aedes species are particularly attracted to the black plastic water containers and flower vases in cemeteries where they oviposit their eggs. Therefore, monitoring of this species was carried out in 12 cemeteries in Zagreb, using ovitraps with masonite strips as a substrate for oviposition. The monitoring was carried out from 2017 to 2020. The traps were inspected and the substrate was replaced every two weeks. This study showed that these two invasive species were present and very abundant in the cemeteries. In the case of Ae. albopictus, a higher population density and a greater number of occupied cemeteries were detected. This species was identified in all 12 cemeteries. Aedes albopictus was identified as the dominant species at all study sites. The spread of Ae. japonicus increased during 2018 in comparison to the previous year. Although this species was present in approximately 9% of the ovitraps, the observed population remained consistent throughout the course of the study. The findings indicate that cemeteries can be considered as significant public health hotspots, as the invasive Aedes mosquitoes tend to develop and reproduce in such environments. Consequently, the mosquito population of these two invasive species may only be reduced by applying integrated mosquito management measures, focused on the education of citizens.