Bioacoustics of Orchestina okitsui

Diagnosis Males of Orchestina okitsui closely resemble those of O. zhiwui Liu, Xu & Henrard, 2019 , O. concava Tong & Li, 2024 and O. subclavulata Song et al. , 2024 by sharing the following characteristics: violet-brown net-like markings on the dorsal carapace; violet-brown pigmentation with a pale inverted V-shaped marking on the dorsal abdomen ( Fig. 1A ); endites with a subapical triangular outgrowth ( Figs 1E–F , 2C, G ); an enlarged palpal tibia; similar relative proportion of tibia and bulb; a short embolus with a wide basal portion; and a dark-colored, elongated seminal duct that is clearly visible ( Figs 1G, K , 2A–B, E–F ). However, they can be distinguished by the length and trajectory of the seminal duct. In O. okitsui , the duct is longer, and its trajectory is more complex, forming multiple loops: three loops are visible between the inner S-shaped loop and the outer duct, and the duct beneath the outer loop (“loop 1”) is distinctly winding ( Figs 1G, K , 2E–F ). In contrast, the seminal duct of O. zhiwui is shorter, forming a simple S-shaped trajectory ( Liu et al. 2019 : fig. 13b; Wang et al. 2021 : fig. 1i); in O. concava , a single loop is visible between the outer duct and the inner loop ( Song et al. 2024 : fig. 5a), and in O. subclavulata , two loops are present between the outer duct and the inner loop ( Song et al. 2024 : fig. 9a–b). Males of O. okitsui also resemble those of O. aureola Tong & Li, 2011 and O. clavulata Tong & Li, 2011 in somatic coloration, abdominal markings and the general shape of the palp, but can be readily distinguished by the presence of a subapical triangular outgrowth on the endites ( Figs 1E–F , 2C, G ), which is absent in O. aureola and O. clavulata ( Tong & Li 2011 : fig. 2a–b). Females of O. okitsui resemble those of O. xui Tong & Li, 2024 in the shape of the internal genitalia, particularly in having an anteriorly swollen AUS with short Pr situated anterolaterally ( Fig. 3F, H ), and a pair of semicircular sclerotized plates on the posterior side of the genital area ( Fig. 3E, G , arrows; Song et al. 2024 : “pockets”). However, they can be distinguished by the globular shape of the anterior portion of AUS and by the position of the “pockets” which are more mesial in O. okitsui , whereas in O. xui the AUS is transversely wider, and the “pockets” are positioned more laterally ( Song et al. 2024 : fig. 18c–d). Females of O. okitsui also resemble those of O. clavulata but can be readily distinguished by the entirely serrated Pr, whereas only the distal end of Pr is serrated in O. clavulata ( Tong & Li 2011 : fig. 7e) and by the presence of a pair of sclerotized plates on the posterior margin of the genital area, which are absent in O. clavulata ( Tong & Li 2011 : fig. 7f).