Environmental factors determining the diversity of darkling beetles (Coleoptera: Tenebrionidae) in arid, high-altitude environments in Northwestern Argentina

Abstract

Factors influencing the diversity of tenebrionid beetles in arid, high-altitude environments in the northwest of Argentina are little-known. Using pitfall traps and suction sampling in 30 sites, we collected these beetles in Altos Andes (AA) and Puna (PU) ecoregions and evaluated how local and regional factors influenced their assemblages. During each sampling date, we registered variables related to climate, vegetation, and soil in each sampling site. In total, we recorded 270 individuals from 21 species, richness of species was higher in PU than in AA, but without a statistically significant difference. Twelve species were present exclusively in PU, while two in AA.Tenebrionid assemblages in both ecoregions had different dominant species, in PU, Psectrascelis cariosicollis while Epipedonota interandina in AA. Beta diversity between ecoregions was moderate and we recorded a high beta diversity and high turnover of species in each ecoregion. The geographical distance between the sites influenced the similarity of the assemblages inside and between ecoregions, therefore, an increase in the geographical distance between sites determined a decrease in the similarity of the assemblages. The increase in elevation of the sampled sites did not produce significant changes in the abundance and richness of Tenebrionidae. There is no individual factor responsible for the darkling beetle communities structuration in these high-altitude environments. Different combinations of both local (soil and vegetation) and regional (climate and geographical distance) environmental factors together explain the ecoregional tenebrionid assemblages. We suggest including them among the focus groups in conservation studies to evaluate anthropogenic activities in this area.

Response of beetle communities to the heterogeneity of vegetation in high altitude habitats in north-western Argentina

“…According to Elgueta (1988) and Jerez (2000), species of this genus are dominant and endemic to the Chilean Andes. It is also worth noting that Tenebrionidae has a high species richness in these ecoregions, which corresponds to the findings of Cruz (2017) and Macagno et al (2023). As evidenced by its diverse dietary preferences and morphological, physiological, and ethological adaptations, this family is one of the most diverse in our country's arid regions (Cheli et al, 2021); they also play an important role in the fragmentation of vegetal and animal matters and food webs (Aballay et al, 2016;Cheli et al, 2022).…”