Recent research has revealed how larvae of the greater wax moth (Galleria mellonella) metabolize low-density polyethylene (LDPE) plastic. The larvae maintain lipid reserves similar to those fed their natural honeycomb diet, even when consuming only plastic[^21].
The wax moth larvae break down plastic through enzymes in their saliva called PEases (Demetra and Ceres), which can oxidize and depolymerize polyethylene within hours at room temperature[^9]. This process occurs without requiring gut bacteria, challenging earlier theories about microbial degradation[^11].
Studies show the larvae's fat body plays a key metabolic role - when fed LDPE, they exhibit enhanced fatty acid metabolism while maintaining normal intestinal function[^27]. This suggests the wax moth larvae have evolved specialized mechanisms to process plastic compounds similarly to their natural wax diet.
[^9]: Nature - Wax worm saliva and the enzymes therein are the key to polyethylene degradation by Galleria mellonella
[^11]: PubMed - Role of the intestinal microbiome in low-density polyethylene degradation by caterpillar larvae of the greater wax moth
[^21]: PubMed - A Very Hungry Caterpillar: Polyethylene Metabolism and Lipid Homeostasis in Larvae of the Greater Wax Moth
[^27]: Science Direct - Fat on plastic: Metabolic consequences of an LDPE diet in the fat body of the greater wax moth larvae