Bioacoustics of Aglaothorax constrictans

Stridulatory file. (n=16) length 3.00– 3.90 mm , 84–107 teeth, tooth density 28.7±2.3 (23.3–32.1) teeth/mm. Song. (n=19) Common small Aglaothorax song with widely spaced, individually countable pulse trains. Length of pulse trains is 50±20 ms. Pulse trains repeat at a rate of 5.31± 0.69 s- 1. Mean peak frequency is 14.35±0.77 kHz. Long, variable echemes contain on average 38±19 (range 12–89) pulse trains. Silent intervals between echemes range from 7 to 29 s. Karyotype. (n=4) 2n ♂ =24 ( 22t +XtYt), paratype T82-47 (S82-51). Recognition. Typical for the Diminutiva Group, the male supra-anal plate is heart-shaped, expanded laterally and indented on the caudal margin, and the paraproct processes have an apical tooth. Otherwise, the morphology of this species is aberrant for the Diminutiva Group, the male titillators and female subgenital plate instead resembling those of the Morsei Group. Male titillator arms are short and barely curved as opposed to long and distinctly curved, the condition found in all other Diminutiva Group species. Females have short, triangular subgenital plate processes instead of long, digitiform processes as in the rest of the Diminutiva Group. For males, the apical position of the mesal tooth on the paraproct process excludes most Morsei Group species from consideration; A. amathitis , A. costalis , A. longipennis , and A. morsei all have a subapical tooth on the paraproct process along with a rounded supra-anal plate. The male titillator arms are notched at the base, a character state shared only with A. morsei . The female subgenital plate lateral processes are longer than wide unlike all Morsei Group females except A. kelainops . Notes. This species is genetically a member of the Diminutiva Group ( Figs. 2–4 ) but possesses morphology that is characteristic of the Morsei Group. Genetically, the closest relative is A. diminutiva which occurs in the South Coast Ranges to the east. Shared morphology may be the result of historical gene flow. Currently the ranges of A. constrictans and A. diminutiva are separated by the Salinas Valley. Other Morsei Group and Diminutiva Group lineages are found in the area where the Transverse and Peninsular Ranges meet in Ventura and Santa Barbara Counties, California , but we have not found any occurrences of sympatry. This species was, however, sympatric with both Neduba carinata Walker and N. lucubrata Cole, Weissman, & Lightfoot at Bottcher’s Gap in the Ventana Wilderness of the South Coast Ranges of California , this occurrence representing the highest count of sympatric nedubine species that we have encountered. The Nature Conservancy protected 25,000 acres of the Bixby Ranch type locality at Point Conception in 2017.