A preliminary study on the distribution of necrophagous flies on Hainan Island, China.

To date, there have been no studies on necrophagous fly populations on Hainan Island in China. Thus, we investigated the species composition of necrophagous flies as well as their geographic distribution on Hainan Island for the first time. Ten sites in different climatic regions across the island were sampled for 7 days per location from November 1, 2018 to February 28, 2019 and from July 1, 2019 to October 31, 2019. Bottle traps made of 1.5 L soft plastic bottles were used to trap necrophagous flies. The collected individuals were identified to species. The specimens represented 5 families and 28 species. Chrysomya megacephala (Fabricius, 1794) was the most dominant species, followed by Chrysomya rufifacies (Macquart, 1843), Hemipyrellia ligurriens (Wiedemann, 1830), Boettcherisca peregrine (Robineau-Desvoidy, 1830), Parasarcophaga dux (Thomson, 1868), Parasarcophaga misera (Walker, 1849), Synthesiomyia nudiseta (Wulp, 1883), and Ophyra chalcogaster (Wiedemann, 1924). The largest collection of flies was obtained in the semiarid region. Species richness was highest in the subhumid region and was higher in summer than in winter, but there were exceptions, such as L. hainanensis (Fan,1965), Boettcherisca formosensis (Lopes, 1961), and Muscina stabulans (Fallen, 1817). Fannia pusio (Wiedemann, 1830), and Boettcherisca formosensis (Lopes, 1961) were newly recorded species on Hainan Island. Of the necrophagous flies collected during the study, we propose several predominant species based on the criteria of distribution, occurrence frequency, and resource preference. Our results not only investigate necrophagous flies on Hainan Island but also accumulate data for criminal investigations in the region.