Bioacoustics of Aglaothorax giganteus

Stridulatory file. (n=4) length 5.00– 5.55 mm , 83–98 teeth, tooth density 17.7±0.9 (16.6–18.7) teeth/mm. Song. (n=15). Loud song of frequently repeated echemes as in A. ovatus . Pulse trains 60±20 ms in length are repeated at a rate of 9.52± 0.88 s - 1 . Mean peak frequency is 12.26±3.41 kHz, with high frequency recordings finding peak frequency energy as high as 19.46 kHz. Echemes group 2–6 (mean 3±1) pulse trains with 0.79–3.02 (mean 1.88±0.64) s silent intervals between echemes. At McMurray Meadows, Inyo County, California on 11-VII-2003 , a 100 m transect was made along a chorus. Four males were found, each in large Purshia bushes, spaced from their nearest neighbors by 25 to 50 m . Singing males were not common and, at this date early in the season, may have been among the first males to mature at this high elevation site. Karyotype. (n=3) 2n ♂ =23 ( 22t +Xt), topotype T82-148 (S82-71). Recognition. Large body size, pronotum 14–15 mm long in male, a size range beginning at the maximum size of male A. ovatus . Red-brown middorsal abdominal stripe and white tegmina, unlike the unstriped abdomen, wood-brown body, and brown tegmina of A. gurneyi . Male paraproct process with a heavy, subapical, ventrally directed tooth, unlike the apical mesally directed tooth of A. segnis and A. strobilion . Pronotum heavily and irregularly rugose on prozona; the only other Ovatus Group species that approaches this condition is A. tinkhamorum , but in that species the prozona appears warty rather than wrinkled. A. giganteus males have an abrupt, strong elevation of the metazona after the transverse sulcus unlike all other Ovatus Group species. Pronotum with abundant longitudinal black streaks on disk; no broad white longitudinal stripes as in A. ovatus , and not with reduced black streaking on disk as in A. armiger and A. tinkhamorum . Female body size overlaps with A. ovatus , but in that species the ovipositor tends to be longer than the hind femur. Notes. The concatenated phylogenetic consensus ( Fig. 4 ) found a monophyletic A. giganteus but paraphyletic relationships were observed with nDNA ( Fig. 2 ) and mtDNA ( Fig. 3 ) gene trees. The original description ( Rentz & Birchim 1968 ) expounds upon this species. Among the discussion, a courtship-copulation sequence was described, and variation between years was hypothesized to be dependent upon variable climate in their arid habitat. We noticed variation in abundance over years as well: the katydids were abundant during collecting events in 2003, 2008, and 2017, all wetter than average years for California that accompanied El Niño Southern Oscillation (ENSO) events, the 2017 event being a particularly strong one. During those years katydids could be found generally throughout the habitat on all types of vegetation. An increase in the number of eggs broken from diapause and increased survivorship due to an abundance of vegetation for food and water are non-mutually exclusive hypotheses for the population booms.