Wing abnormalities and morphological differences in the edible moth Omphisa fuscidentalis (Lepidoptera: Crambidae) from northern Thailand

Abstract The larvae of Omphisa fuscidentalis (Lepidoptera: Crambidae), commonly known as the bamboo borer, are traditionally consumed fried in northern Thailand, where they are regarded as a seasonal delicacy with cultural and economic value. Recent observations of wing deformities in adult moths have raised concerns about potential effects on fitness and dispersal. This study investigates morphological differences between adults with normal and abnormal wings by comparing body mass, adult length, and wing structure. Specimens were reared from pupae collected in northern Thailand, where local collectors have also reported a noticeable decline in larval abundance. Among the examined individuals, 50% of females and 36% of males exhibited wing deformities. While body weight and abdominal length did not significantly differ between groups, both the forewings and hindwings of abnormal individuals were significantly reduced in size, suggesting limitations in flight ability. In contrast, wing venation patterns and scale microstructures were consistent between normal and abnormal individuals, indicating that the deformities were size-related rather than structural. These findings provide a foundational reference for understanding wing abnormalities in this culturally significant species and underscore the importance of further research into the ecological or genetic factors contributing to these deformities. Such knowledge could enhance understanding of population dynamics and inform future conservation or sustainable harvesting strategies.