Philmontoides wau Ingrisch, 2022

Morris, Glenn K, Ingrisch, Sigfrid, Willemse, Fer, Willemse, Luc, De Luca, Paul A. & Klimas, Dita, 2025, Stridulation songs of some Tettigoniidae (Ensifera, Orthoptera) from Papua New Guinea, Zootaxa 5600 (1), pp. 1-81 : 53-56

Philmontoides wau Ingrisch, 2022

( Figs 53–58 )

Specimens studied, including holotype and paratypes. Papua New Guinea, Wau Ecology Institute ( WEI)., 30 vii 1981, 4 & 12 viii 1981 on Pandanus , remnant forest Wau, G.K. Morris (4 males, 2 females) ; PNG, McAdam Nat. Park , Bulolo Gorge, 28 viii 1981 (1 female) .

Comments. P. wau is one of 8 species grouped by Ingrisch (2022) into the genus Philmontoides Ingrisch, 2022 . Type species of this genus is Lobaspis hageni Dohrn, 1905 . For Philmontoides wau the male holotype was chosen from among specimens collected by GKM and DEK: Papua New Guinea ( PNG), Morobe Province, Wau, 12 viii 1981, leg. G.K. Morris, [recording designation 81-2]. Depository: Naturalis Biodiversity Center, Leiden (NBC). Specimens found only on Pandanus [GKM].

Tremulation. Substrate signalling, observed as tremulation (body oscillations with or without impact, imparting vibratory substrate waves to a plant perch) is widespread among tettigoniids (e.g., Morris 1980, De Luca & Morris 1998, Hill 2008). A male and female of P. wau were placed together onto a Pandanus leaf where the male engaged repeatedly in tremulation bouts.

Stridulation. — To a human listener the song is a regular repetition of faint crackles, resembling a stereotyped precise static, so faint you must be very close to hear. The calls are relatively intense in the ultrasonic.

Song parameters are averaged from recordings of two different singers. Based on the time domain being widely spaced short sinusoid ultrasonic pulses, this is an elastic uncoupled stridulation. The carrier is a fairly high-Q ultrasonic frequency, peaking at 26.9 kHz ( Fig. 58C, E ). Calls repeat at a rate of about 11/s near 20°C; each call consists of a train of identical 4–8 time-separated sinusoid pulses ( Fig. 58D ) comprising a major pulse train. A faint (putative opening) sound/train occurs before each intense (putative closing) train.

Philmontoides has a genus-diagnostic file form (figured by Ingrisch Fig.12H ), a region of perhaps non-functional teeth extending over the file’s distal third. This leaves just 15 or so broad, distinctly spaced, teeth available to make the several ~7-wave 27-kHz sinusoids, which suggests some reversals of scraper direction during a train, i.e., there are not enough teeth on a one-wave one-tooth basis to complete one whole pulse train on one closure.

Figures

FIGURE 12. SEMs comparing scrapers Paraphyllomimus spp.; view of right tegmen underside, scrapers low in foreground; broadly flattened transverse vein conveys forces to and from each scraper; vestigial file absent: A) P. pipiens sp. nov. B) P. buergersi wauensis ssp. nov.

FIGURE 53. Philmontoides wau; habitus of hand-held male, dorsolateral aspect.

FIGURE 54. Philmontoides wau, lengthy antenna.

FIGURE 55. Philmontoides wau; habitus of female, lateral view.

FIGURE 56. Philmontoides. wau base of ovipositor and subgenital plate in ventral view; scale 1 mm.

FIGURE 57. Philmontoides wau stridulatory file on ventral surface of left tegmen.

FIGURE 58. Philmontoides wau acoustic analysis, an example of elastic stridulation:A) time sample of 8 complete phonatomes (to-fro tegminal cycles), each comprised of a more intense (presumed) closing train of 4–6 short pulses well-isolated in time, separated by a faint (presumed) opening sound; B) 5 pulses of a closing train at higher resolution; C) Fourier power spectrum of the time sample in B; the most intense frequency is a coherent symmetric peak in the ultrasonic centred near 27 kHz; D) One pulse from B at very high time resolution showing its ultrasonic sinusoid waveform; E) Spectrum of the pulse in D shows ultrasonic peak at 27 kHz.