Improper handling of animal manure generated from concentrated swine operations greatly deteriorates water ecosystems. In this study, a full-scale vermireactor using housefly larvae (Musca domestica) was designed to investigate the effectiveness and efficiency of swine manure reduction, and to explore the associated biochemical-biological mechanisms. The one-week larvae vermireactor resulted in a total weight reduction rate of 106 +/- 17 kg/(m(3) d) and moisture reduction of 80.2%. Microbial activities in manure decreased by 45% after vermicomposting, while the activities of cellulose, proteases, and phosphatases in the vermicompost were significantly 69 times, 48%, and 82% lower than those in raw manure, respectively. The vermicompost was exclusively dominated by Entomoplasma somnilux, Proteobacterium, and Clostridiaceae bacterium where the microbial diversity was decreased from 2.57 in raw manure to 1.77. Correlation coefficients statistic showed that organic C might be a key indicator of the biochemical features and microbial functions of the larvae vermireactor. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.