Distribution and density of Aedes albopictus in Jiading District of Shanghai in 2020

Objective To determine the seasonal fluctuation and population distribution of Aedes albopictus in Jiading District， and provide scientific evidence for the prevention and control of dengue fever and other Aedes-borne diseases.

Methods In 2020， the mosq-ovitrap method and mosq-ovitrap index （MOI） were used to monitor and evaluate the density of Aedes albopictus in Jiading District. Spatial and temporal distribution of Aedes albopictus was determined. Chi-square test was used for statistical analysis.

Results In 2020， the annual average MOI was determined to be 4.10， which was under safety threshold. The seasonal fluctuations showed a unimodal distribution， which peaked in July. The fluctuation trend in urban area was similar to the overall trend， while that in the non-urban area showed a bimodal distribution with peaks in June and August. The density of Aedes albopictus at different monitoring sites varied widely，with the highest MOI （6.64） at Anting town and the lowest MOI （2.09） at Huating town. The distribution of Aedes albopictus in different habitats also varied widely； the highest density was observed in environments as waste collection stations and construction sites， with the highest MOI 33.33 in waste collection stations in peak season. The MOI value of Aedes albopictus in residential areas was significantly higher than that in non-residential areas （χ² = 6.082， P = 0.014）.

Conclusion Aedes albopictus is quite common in Jiading District. In certain areas， Aedes density may exceed the safety threshold from May to September. More targeted mosquito control measures should be implemented in waste collection stations， construction sites and residential areas.