Altitudinal Distribution of Fireflies (Coleoptera: Lampyridae) in the Tacaná Volcano, Mexico

Fireflies (Coleoptera: Lampyridae) serve as bioindicators due to their sensitivity to environmental changes; however, their ecological distribution remains insufficiently documented. The Tacaná Volcano in Chiapas, Mexico, represents a biodiversity hotspot with diverse altitudinal ecosystems. This study investigates the altitudinal distribution of fireflies in this region through systematic sampling at four sites ranging from 278 to 2181 m a.s.l. between July and November 2023, employing both aerial nets and Malaise traps. A total of 226 specimens, representing 20 species across seven genera and five tribes, were identified. The greatest species richness was observed at mid-elevations (740-1191 m a.s.l.), particularly in shade-grown coffee plantations, where humidity and canopy cover emerged as significant environmental variables. Species richness was quantified using Hill numbers, while the Jaccard index assessed compositional similarities among sites. Generalized linear models (GLMs) and canonical correspondence analysis (CCA) evaluated the relationships between firefly abundance, species richness, and environmental parameters. Firefly abundance demonstrated positive correlations with temperature, humidity, and canopy cover, while precipitation exhibited a negative correlation. Nevertheless, no single environmental variable was identified as a definitive determinant of species richness. New distributional records reinforce the conservation significance of the Tacaná Volcano. Malaise traps proved to be an effective complement to traditional sampling techniques, facilitating the capture of diurnal and non-bioluminescent species. The highest species diversity and abundance were recorded in shaded coffee plantations, which provide stable microclimatic conditions conducive to firefly populations. Conversely, lower diversity was documented at the lowest and highest elevations, likely attributable to habitat constraints. This study highlights the importance of continued research to elucidate the ecological drivers influencing firefly distribution and to inform conservation strategies. Given the identification of novel species and new distributional records, the Tacaná Volcano should be recognized as a priority site for biodiversity conservation and entomological studies.