Although　worm　predation　is　effective　for　excess　sludge　reduction,　it　usually　needs　large　land　facility　and　high　operational　cost.　In　this　study,　Chironomid　larvae　(CL),　a　novel　microfauna　for　sludge　treatment　was　applied　to　a　one-stage　sludge　reduction　system　(sequencing　batch　reactor,　SBR).　The　results　showed　that　adding　CL　induced　the　sludge　reduction,　and　the　sludge　production　rate　was　31%　lower　than　that　in　the　control.　Low　volatile　suspended　solids/suspended　solids　(VSS/SS)　ratio　(0.77)　and　sludge　volume　index　(70　mL/g)　were　achieved.　Moreover,　adding　CL　did　not　deteriorate　the　contaminant　removal　(organic　carbon　and　nitrogen),　and　the　competition　between　CL　and　nitrifying　bacteria　for　oxygen　was　beneficial　for　nitritation.　(C)　2015　Elsevier　B.V.　All　rights　reserved.