Bioacoustics of Paraphyllomimus buergersi

( Figs 5–8 , 9B , 10 BDF, 11B, 12B, 13B, 14) Specimens studied. Holotype (male): “30.VIII.81, Mt. Kaindi 81-2 squeaker confirmed”, “nr. Wau PNG 2-2 coll. G.K. Morris ” (depository, NBC Leiden) Paratypes : PNG , Mt , Kaindi , 30 viii 1981 , G.K. Morris ( 3 males ) & idem, contour trail 19 viii 1981 ( 2 males ) (all NBC ) . Description. Male.—General appearance ( Fig. 9B ), size and coloration as in nominate subspecies but differing as follows: posterior margin of last abdominal tergite slightly sinuately excised, cercus strongly upcurved, tip not recurved, styli slightly longer ( 1.3–1.4 mm ) than stalk of subgenital plate ( 0.74–0.85 mm ) ( Fig. 10 BDF). Elytron as in nominate form but stridulatory area of left elytron slightly larger, length 6 mm , width 3 mm ; file in dorsal aspect inflated over a shorter distance ( 2.1–2.4 mm ); file in ventral view slightly longer, shortest distance between most proximal and distal tooth 2.9–3.0 mm, teeth wider, maximum width 0.175 mm , total number and spacing about similar as in nominate form, in mid part about 24 per 0.25 mm . Female.—The female Paraphyllomimus in one of our photographs ( Fig. 8 ) bears a spermatophore and may be either of P. buergersi wauensis or P. pipiens ).

Comments. The most obvious differences between nominate P. buergersi and P. b. wauensis are the strongly recurved male cerci and relatively longer styli in the latter.Whether the slight differences of the stridulatory apparatus are important is an open question, mainly as variability and song of the nominate form are unknown. For the time being we propose to give the new taxon subspecies status. Stridulation. Call period during steady singing near 20°C is ~ 0.4s ( Fig. 14A ), slightly more than 2 calls per sec. Slowed by a factor of 16, the call is heard as a fast repetition of highly tonal pulses: three shorter sinusoids lengthen and intensify into a concluding most intense wave train lasting ‘almost 20 ms’ ( Fig. 14B ). The strongly sinusoidal nature of the pulses is apparent in a time sample from this last and longest pulse ( Fig. 14D ). An FFT spectrum of one complete song shows a dominant frequency peak at ~11 kHz ( Fig. 14C ) with a Q 10 of 5.7. Spectra calculated early and late during the ‘almost 20-ms’ prolonged pulse of Fig. 14B show an upward frequency modulation (FM) of ~1000 Hz. Two arrows ( Fig. 14B ) mark the start of each of these 512-point time samples. The two resulting FFT spectra are overlain in Fig. 14E : from 10.9 kHz the carrier peak shifts to 11.9kHz. The Q 10 value of 5.7 determined on the whole call is misleadingly low. The peak of one of the spectra in Fig. 14E has a Q 10 of about 20. The insect is engaged in resonant stridulation and contacts teeth at an increasing scraper speed. Frequency modulation is rare in tettigoniid stridulations, but is known for several species (e.g., Morris et al. 2016 and see Eumecopoda cyrtoscelis and pumila in the present paper).

Comments. Type species of the genus Paraphyllomimus is P. apterus Beier, 1954 by original designation. This genus was known from three species, all from NE New Guinea (Beier 1954). It was a surprise to find, high on Mt. Kaindi, morphologically similar specimens from the same region of undisturbed forest producing two different songs. As well, from differences of the male stridulatory file it became clear we deal with two distinct species. One of our species from Wau comes near P. buergersi . The latter is known only from the male holotype . By lack of sufficient data in the original description it became necessary to compare the holotype with our specimens. Opportunity is taken here to give some additional notes on this specimen. Stridulation. Song unknown.

( Figs 9A , 10 ACE .) Specimens studied. Holotype male: “D.N. Guinea Schraderberg 2100 m 22.–31. V .13 Kais. Augustafl. Exp. Burgers S.G.”, “no. 344”, “ Paraphyllomimus buergersi n. sp. det. Beier male Type!” ( Zool. Mus. Berlin ). Redescription of holotype . General appearance as in Fig. 9A . Cercus slightly upcurved, tip smooth, somewhat flattened and recurved; posterior margin of last abdominal tergite very broadly wedge-like excised, lateral margins of the thin supra-anal plate shriveled and curled, creating a biconcave profile in dorsal view; styli about as long ( 1 mm ) as stalk of subgenital plate ( Fig. 10 ACE ). Foremost part of median carina of pronotum depressed and pale yellow, bordered laterally with dark brown stripe on either side. Number and size of dark dots in elytron cells limited by R , origin of Rs and part of M and adjacent cell between M and Cu remarkably larger than the single dots in other cells. Stridulatory area of left male elytron 5.5 mm long, 2.6 mm wide, rectangular distally, file dorsally inflated over 2.5 mm ; file in ventral view of usual shape, shortest distance between most proximal and distal tooth 2.5 mm , greatest width of teeth 0.125 mm , total number of teeth>200, almost regularly spaced, in mid part about 27 teeth per 0.25 mm .