Toxicity and bioconversion: Meta-analytical insights into microplastic effects on black soldier fly rearing

The black soldier fly larvae (BSFL), Hermetia illucens, have emerged as a sustainable solution for converting organic waste into a valuable resource. However, the pervasive presence of microplastics (MP) in municipal and agricultural waste streams raises concerns regarding their potential impact on BSFL development and waste processing efficiency. This systematic review and meta-analysis synthesizes findings from existing literature to assess the effects of MP on BSFL growth, survival, and waste degradation. A total of 24 studies were selected through PRISMA guidelines, and effect sizes were calculated using Hedges' g. Results showed inconsistent yet significant effects of MPs on larval weight and (pre-)pupation rate, with a notable negative impact on waste reduction. While certain plastics, such as polyethylene and polystyrene, were partially degraded by BSFL, others, including polyethylene terephthalate (PET) and polyvinyl chloride (PVC), remained persistent. The ingestion of MP varied with particle size and concentration, with some evidence of bioaccumulation and interaction with other contaminants such as heavy metals and pesticides. These findings underscore the need for standardized methodologies and further research into the environmental risks of MP-laden substrates. This study provides a critical foundation for developing safer and more effective BSFL-based waste management practices in contaminated environments. SYNOPSIS: Despite increasing recent attention on the interaction between black soldier fly larvae and microplastics due to environmental concerns, research remains limited and inconsistent. This is the first study to provide a comprehensive review with a meta-analysis, synthesizing current knowledge on the topic.