Decomposition abilities and characteristics of pig manure using three insect larvae

Abstract This study investigated the effects of three insect larvae on decomposition abilities and survival rates in Experiment 1 or on pH, total nitrogen, total carbon, and C/N ratio in Experiment 2. A total of hatched 7,500 Tenebrio molitor (TM) larvae, hatched 501 Protaetia brevitarsis seulensis (PBS) larvae, and hatched 15,000 Ptecticus tenebrifer (PT) larvae were randomly subjected to three treatments with three replicates. The treatments were as follows: (1) TM, 5,000 g pig manure + 250 g TM larvae; (2) PBS, 5,000 g pig manure + 250 g PBS larvae; and (3) PT, 5,000 g pig manure + 250 g PT larvae. In Experiment 1, there were significant differences ( p < 0.05) in the decomposition abilities of the pig manure from the three insect larvae‐treated groups for 15–30 days. No significant differences in survival rates were observed for any of the in all treatments over time. Decomposition ability and survival rates in pig manure were higher in the PT larvae group than in the PBS and PT larvae groups. In Experiment 2, three insect larvae‐treated pig manure treatments had an effect on total nitrogen for 20 and 30 days, total carbon for 10 and 30 days, and C/N ratio for 20 and 30 days. Thus, our results suggest that the three insect larvae have the ability to decompose pig manure to increase for increasing survival rates or might represent a valuable alternative as organic fertilizer, which could increase the total nitrogen content and decrease C/N ratio.