Nemo-like kinases (NLKs) integrate multiple signaling pathways and exhibit functional diversity in developmental processes, including the bone morphogenetic protein (BMP) pathway. However, their roles in insect wing development, particularly in hemimetabolous insects like the brown planthopper (Nilaparvata lugens), remain poorly understood. Here, we investigated the role of Nlnemo (Nlnmo), an NLK, in the wing development of N. lugens. We cloned and characterized Nlnmo and found it highly conserved across insect species. Expression analysis revealed higher Nlnmo levels in brachypterous compared to macropterous strains, particularly in wing buds. RNA interference (RNAi) of Nlnmo led to enlarged wing and thickened veins, indicating its inhibitory role in wing development. Further analysis revealed that Nlnmo suppresses BMP signaling by downregulating Nlmad1 and Nldpp. Dual knockdown of Nlmad1 and Nlnmo demonstrated that Nlnmo mitigates Nlmad1-mediated effects on wing development. These findings establish Nlnmo function as a key suppressor of wing development in N. lugens via BMP signaling inhibition through Nlmad1. This study deepens our understanding of the molecular mechanisms underlying wing development in in N. lugens and highlights potential pest management strategies by targeting migration-related traits.