Can the plastic-eating insect Alphitobius diaperinus be used as a new biodegradation agent for synthetic plastic insulator wastes?

Abstract

The long lifespan and inadequate waste management of plastics are responsible for a global environmental pollution and have significant consequences for ecosystems. Several insect species are avid plastivores, as for instance Tenebrionids which can biodegrade polystyrene and polyethylene. The lesser mealworm, Alphitobius diaperinus, is a pest of poultry farming facilities where it damages isolation panels. In this study, lesser mealworms were offered four different insulating plastic materials as food source and their effects on growth, energy stores and chemical biodegradation were studied. Both larvae and adults were observed consuming plastics, but with a clear preference for polystyrene and an absence of consumption for the dense polyisocyanurate material. Polystyrene consumption was 1.9 ± 0.77 mg per larva (over 30 days) and 5.5 ± 1.7 mg per adult (over 40 days). Plastic ingestion alone did not provide sufficient nutrients to the insect resulting in mortality, body mass loss, as well as reduced body reserves (glucose and triglycerides). We demonstrated partial biodegradation of polystyrene within larvae’ and adults’ gut, as indicated by chemical modifications observed in FTIR spectra and the degradation products identified through pyrolysis GC/MS analysis. In conclusion, A. diaperinus demonstrated the ability to consume and partially biodegrade plastics, particularly polystyrene. However, detrimental effects on survival, body weight, and energy reserves suggested that it is unlikely to be a viable solution for biodegrading plastic wastes if fed only with polystyrene. However, when provided with other nutrients such as cereals, it could potentially serve a beneficial role.