Bioacoustics of Aglaothorax armiger

Stridulatory file. (n=5) length 3.90–4.80 mm , 94–106 teeth, tooth density 23.1±1.4 (20.8–24.1) teeth/mm. Song. (n=7) Sporadic song that consists of single pulse trains or brief echemes. Pulse trains 50 ms in length are repeated at a rate of 10.26± 0.97 s- 1. Mean peak frequency is 11.58±0.83 kHz. Males may produce pulse trains alone or group them into echemes containing 1–4 (mean 3±1) pulse trains. Isolated pulse trains are more likely to occur at the onset of singing or after a male is disturbed. Silent intervals between echemes last 1–6 (mean 2.16±1.70) s. The original description mentions intermittent sound production during an afternoon ( Rehn & Hebard 1920 ). Karyotype. (n=5) 2n ♂ =23( 22t +Xt), S86-104, T86-98, topotype . Recognition. Morphology, coloration, geography. Ground color is generally tan or yellow, unlike the rich green that is common in other Ovatus Group species or the wood-brown coloration of A. gurneyi . The abdominal dorsum has a reddish stripe and the tegmina are white, unlike the wood-brown unstriped abdomen and brown tegmina of A. gurneyi . The male supra-anal plate of A. armiger is wider than long in contrast to A. giganteus , A. khioneos , A. ovatus , and A. tinkhamorum , which have supra-anal plates that are as long as wide. From 16 to 18 mm long, the hind femora appear shorter than those of A. giganteus , A. ovatus , and A. tinkhamorum . The male paraproct process is about twice as long as wide, cylindrical, and with a subapical ventrally directed heavy triangular tooth, unlike the apical tooth on the slenderer processes of A. segnis and A. strobilion . Black markings are generally reduced on the pronotal disk to a central pair of black spots and perhaps limited black streaking, a coloration otherwise approached only by A. tinkhamorum . Notes. The type locality of A. armiger , Lee Canyon , is a sky island in the eastern Mojave Desert that is known for its endemism, and as a biodiversity hotspot for Orthoptera in particular ( Rentz 1972 ). A. armiger populations are distributed to the east of Mount Charleston in the rain shadow. White Mountains, California populations classified as this species ( Rentz & Birchim 1968 ) are here described as new (see A. khioneos species account below).

Fig. 6 (distribution), Fig. 11 (male and female habitus, calling song, male and female terminalia, karyotype), Plate 4 (male terminalia), Plate 7 (female subgenital plate), Plate 10 (male titillators), Plate 14 (male calling song). Common name. Armored Shieldback. History of recognition. Described in Aglaothorax ( Rehn & Hebard 1920 ) . Correctly identified and associated with type material by Tinkham (1944) . Transferred to Neduba ( Aglaothorax ) and relegated to a subspecies of N. (A.) ovata ( Rentz & Birchim 1968 ) . Transferred back to Aglaothorax ( Rentz & Colless 1990 ) where this species is currently classified as an A. ovatus subspecies ( Cigliano et al. 2025 ). We elevate A. armiger to species rank based on phylogenetic and morphological evidence, reinstating the taxonomic status of this species as originally described.