Bacteria communities predicting insect composition on an ephemeral resource

Vertebrate carrion in terrestrial systems is generally an unpredictable and ephemeral resource pulse, and studying this ecosystem process is important for elucidating species interactions and mechanisms important to decomposition. Carrion may attract a wide range of species with a variety of life history traits. Location and colonization by insects can occur quickly or be delayed depending on abiotic and biotic factors. However, few studies have evaluated how bacterial communities can impact insect community composition, succession, and the resulting process of decomposition.

We hypothesized that carrion associated bacterial communities would influence necrophagous insect succession patterns, demonstrating marked shifts in species composition, turnover rates and assembly. To test this hypothesis, we surveyed bacteria and insect community composition throughout vertebrate carrion decomposition. There was a significant correlation (Pearson’s correlation coefficient: -0.92, n = 12, P < 0.0001) between bacteria and insect taxa richness with a unimodal response of taxa richness throughout decomposition. In early stages of decomposition, there was high bacteria taxon richness with few insect taxa present. However, as decomposition progressed bacteria richness was reduced as the number of insect taxa increased.

Understanding the interactions within and across trophic levels could lead to elucidating the mechanisms governing insect succession on carrion. We provide information of bacterial communities and their potential interactions with necrophagous insects. This work provides a foundation of empirical data that may be useful in future work to determine how bacteria and insects drive the ecology of ephemeral resources.