Living on the edge: urban fireflies (Coleoptera, Lampyridae) in Morelia, Michoacán, Mexico

PeerJ. 2023 Dec 14:11:e16622. doi: 10.7717/peerj.16622. eCollection 2023.

Abstract

Fireflies (Coleoptera, Lampyridae) are a globally threatened group of insects due to habitat loss and fragmentation, light pollution, climate change and pesticides. However, against all odds, some firefly populations persist in urbanized environments where all four of these factors are present simultaneously. In this work, we compiled several data sources to document the diversity of fireflies in the urbanized area of Morelia, characterize their current habitats, and determine the main stressors affecting these bioluminescent insects. We found seven genera and 26 species of fireflies (19 nocturnal, seven diurnal) associated with 32 urban, peri-urban and extra-urban areas; at least, 14 are new records for Michoacán, and the list for the state now includes nine genera and 41 species. Five additional sites were documented as extinction sites. We compared the characteristics of these five sites with those of the sites with extant populations. We found that in Morelia, fireflies are mainly associated with areas that have high to moderate proportions of vegetation cover, are near water bodies, have very gentle to moderate slopes, and are exposed to low levels of light pollution. In contrast, the extinction sites showed high proportions of artificial surfaces and high levels of light pollution. Because some fireflies are considered bioindicators of ecosystem integrity as they are associated to specific habitats, are highly diverse and due to their sensitivity to environmental changes, we consider that sites from Morelia's urban core and extinction sites show the highest levels of environmental degradation, threatening most fireflies and other insects living in the urban core with local extinction. At the same time, our results also suggest that implementing conservation strategies and sustainable planning for the urban development of Morelia in the short term could allow fireflies and other vital elements of the city's insect communities to persist for future generations. Restoration and conservation of green areas and nighttime environments are essential for biodiversity and human health, especially in intra-urban zones.

Keywords: Citizen science; Conservation areas; Light pollution; Local extinction; Nocturnal insects; Peri-urbanization; Photinus; Photuris; Urban green areas; Urbanization.

MeSH terms

  • Animals
  • Coleoptera*
  • Ecosystem
  • Fireflies*
  • Mexico

Grants and funding

Entomological sampling for this work was funded by the Coordination of Scientific Research, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH) and the Institute of Science, Technology and Innovation of the Government of Michoacán, through the Program for Scientific Research Projects of Regional Impact (PICIR-071). The National Council of Science and Technology (CONAHCyT) funded Cisteil Xinum Pérez-Hernández’s postdoctoral project, of which this publication is a part, through the program “Estancias Posdoctorales por México”. This work was published using the annual institutional membership of the Universidad Michoacana de San Nicolás de Hidalgo through the joint support of the Institute of Science, Technology and Innovation of the Government of Michoacán, through the Program “Comparte tus Ideas” (ICTI/D.A./213/2023) and the Coordination of Scientific Research, Universidad Michoacana de San Nicolás de Hidalgo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.