Analysis on density and seasonal fluctuation of flies in Wenzhou, Zhejiang, 2017–2020

  Objective  To monitor the density and seasonal fluctuation of flies in Wenzhou, Zhejiang province, and provide scientific evidence for fly control.

  Methods  Cage traps were set up in the following four types of habitats: farm produce markets, catering external environment, greenbelts and residential areas.

  Results  A total of 7197 flies, belonging to 4 families, 8 genera, and 13 species, were captured from 2017 to 2020. The predominant species were Musca domestica, Sarcophagidae, Musca sorbens, Lucilia sericata, Chrysomya megacephala and Lucilia cuprina. The annual density peak was during June - September. The highest density was 2.99 flies/cage in 2017, and the lowest population density was 1.93 flies/cage in 2018. In the four types of habitats, greenbelts had the highest fly diversity, where 13 species were found, and the highest fly density was found in farm produce markets with an average of 3.06 flies/cage.

  Conclusion  The populations of calyptrate flies were abundant in Wenzhou. The predominant species, such as Musca domestica, Sarcophagidae, Musca sorbens, and Lucilia sericata, should be the focus of fly control. Primary control measures should be taken in farm produce markets and during June - September for the prevention and control of fly-transmitted diseases.