Valorization of Water Lettuce (Pistia stratiotes L.) Through Bioconversion for Black Soldier Fly Larvae (Hermetia illucens): Larvae Growth, Survival Rate, and Nutritional Quality

The rapid proliferation of water lettuce, <i>Pistia stratiotes</i>, poses significant ecological challenges. This study investigates the use of <i>Pistia stratiotes</i> as a substrate for producing black soldier fly larvae. The experiment used 40 g of black soldier fly larvae (BSFL) pupae for all five substrates (T0, T25, T50, T75, and T100). Each treatment had three replicates. The physicochemical parameters, such as the temperature and pH, ranged from 27.30 °C to 27.40 °C and from 7.03 to 7.60, respectively. The survival rates ranged from 90.13% to 94.73%. The biochemical parameters showed significant differences, including dry matter, organic matter, ash, crude protein, crude lipid, crude fiber, carbohydrate, and energy (<i>p</i> < 0.05). Regarding the larvae's growth and substrate use, the BSFL production varied depending on the rearing substrate. The highest growth was observed in substrates without water lettuce leaf (WLL) (T0), followed by those in treatment at 25% (T25) and 50% (T50) inclusion of WLL and then the substrate made solely of WLL (T100). The substrates degradation rate in this study varied significantly, ranging from 46.40% to 67.38%. The physicochemical characteristics of the substrates are associated with the growth performance of the BSFL, and the inclusion of WLL influenced the nutritional composition of the larvae.