Morphological comparison of the forewing stridulatory file between two mole crickets Gryllotalpa orientalis Burmeister, 1838 and Gryllotalpa unispina Saussure, 1874 (Orthoptera: Gryllotalpidae)
摘要
Stridulatory files are key structures for acoustic signaling in mole crickets, but their fine-scale morphology remains poorly documented. In this study, we present a comparative analysis of the forewing stridulatory files in both males and females of Gryllotalpa orientalis Burmeister, 1838 and Gryllotalpa unispina Saussure, 1874 using scanning electron microscopy (SEM). In both species, the male stridulatory file is positioned along the Cubitus posterior (CuP) vein and exhibits no significant left-right asymmetry. Marked interspecific differences are nevertheless observed: males of G. unispina possess longer files with a greater number of teeth and narrower inter‑tooth spacing than those of G. orientalis. Female stridulatory structures show even greater divergence. Females of G. orientalis bear a file restricted to the CuP vein, whereas females of G. unispina exhibit a composite file extending across CuA2, CuP, and 1 A veins. Additionally, two distinct morphotypes of sensilla trichoidea occur at the distal region of the male file in G. orientalis but are absent in G. unispina, while sensilla campaniformia are present adjacent to the file in both species. This study provides a detailed morphological comparation of stridulatory files in two closely related mole crickets, and documents interspecific and sexual variation of file structure in Gryllotalpidae.