RNA interference (RNAi) technology is a promising crop protection strategy against agricultural pests. The soybean pod borer (SPB), Leguminivora glycinivorella (Mats.), is a serious pest of soybean in northeastern Asia. The neonate larvae of SPB are endophagous, initially feeding on the inner layer of the pod and then on the immature soybean seeds, a behavior that makes them difficult to rear. Therefore, a suitable artificial diet is desirable to facilitate RNAi research. Seven artificial diets and soybean pods were used for rearing SPB neonate larvae. The survival and mean weight of the larvae reared on artificial diet 6 (A6, included 2 g soybean flour and 10 g R3 immature soybean pod powder) were found to be significantly higher than those for larvae reared on all other diets. Subsequently, A6 diet was prepared in DEPC-treated water to obtain a RNase-free artificial diet (RF). The survival and mean weight of the larvae were not significantly different between A6 and RF diets. Feeding neonate larvae with RF-SpbP0 dsRNA (ribosomal protein P0) silenced SpbP0 gene, resulting in arrested development and increased mortality. The results of this study suggested that the newly developed A6 or RF diets could rear SPB neonate larvae and help towards developing an effective method for oral delivery of dsRNA to SPB larvae.