Partial consumption of medical face masks by a common beetle species

The widespread distribution of microplastics (MPs) in the environment has
motivated research on the ecological significance and fate of these
pervasive particles. Recent studies have demonstrated that MPs may not
always have negative effects and in contrast, several species of
Tenebrionidae beetles utilized plastic as a food source in controlled
laboratory experiments. However, most studies of plastic-eating insects
have not been ecologically realistic, and thus it is unclear whether
results from these experiments apply more broadly. Here we quantified the
ability of mealworms (Coleoptera: Tenebrionidae) to consume MPs derived
from polypropylene (PP) and polylactic acid (PLA) face masks; these are
two of the most commonly used conventional and plant-based plastics. To
simulate foraging in nature, we mixed MPs with wheat bran to create an
environment where beetles were exposed to multiple food types. Mealworms
consumed ~50% of the MPs, egested a small fraction, and consumption did
not affect survival. This study adds to our limited knowledge of the
ability of insects to consume MPs. Understory or ground-dwelling insects
may hold the key to sustainable plastic disposal strategies, but we
caution that research in this field needs to proceed concomitantly with
reductions in plastic manufacturing.