Soybean isoflavones and flavonoids of Artemisia argyi enhanced conversion of chicken manure by black soldier fly (Hermetia illucens L.) larvae and effects on microbiota of their larvae and residues

•Flavonoids of artemisia argyi could dramatically improve the conversion efficiency of crude protein in chicken manure by black soldier fly.•Flavonoids might promote the conversion of crude protein in chicken manure by the black soldier fly larvae through regulating their intestinal microbiota.•Flavonoids of artemisia argyi could dramatically improve the weight and nutrition of larvae.