Account
What the sources say about this taxon, as written.
description · 
Plazi
Measurements: see Tab. 6 . Song. The calling song of the species consists of trills with durations from several seconds to more than a minute ( Fig. 10 ; Tab. 7 ). It should be noted that the stridulatory file of a male from Sideia Island (extreme SE New Guinea ), identified as E. cyrtoscelis ( Rentz et al. 2006 ) , differs distinctly from our specimen and from that of Helfert & Sänger (2007 ; see Fig. 12 ). Coloration. Dark brown.
etymology · Plazi
Derivatio nominis. Named in honour of Prof. Dr. R. D. Zhantiev, Moscow State University, the pioneer of bioacoustics of insects (author of a book with same title in 1981 and of many papers before and after this date) in the USSR and Russia .
diagnosis · Plazi
Diagnosis. In the calling song of the species, trills with durations from several seconds to more than a minute were observed, clearly different from the much shorter segments of a „broken trill“ (called „continuous (short) caller“ by Römer in Helfert & Sänger 2007 ) observed in Eumecopoda c. cyrtoscelis by Helfert & Sänger (2007 ; fig. 32). In morphology, possibly some body relations like tegmen to femur in the female differ between subspecies (or populations) but there are too few data for safe conclusions.
description · Plazi
( Figs 22 –25, 30, 31, 82AB) Specimens studied. PNG , Wau W.E.I. 30 vii & 4 viii & 23 viii 1981 , remnant forest understory, G.K. Morris 3 males ; Bulolo Gorge, McAdam Nat. Pk. , 28 viii 1981 , G.K. Morris ( 1 female ). (Depository NBC Leiden) . Systematics. .The specimens agree with the nominate form. Habitat. Found on low vegetation alongside forest paths. Both Eumecopoda spp. descended to the bottom of their cages during the day becoming immobile. But when disturbed they reacted explosively: Dita was very effectively startled when she investigated one inert male that suddenly leaped away. Once it gets dark the insects climb back up in their cages and begin to sing. Stridulation. Each E. cyrtoscelis call continues for several seconds at a time ( Fig. 30A ) and each call initiates with single high intensity sound (see arrow in Fig. 30A ). At increased time resolution these calls are seen to be composed of two sorts of simple sine waves, i.e., two different carrier frequencies ( Fig. 31A–C ). There is a less intense higher frequency and a more intense lower frequency. Both carrier frequencies, 3.1 and ~6.7 kHz, lie in the low audio range and are harmonically related, alternating rather than co-occuring, so providing an example of resonance stridulation together with sequential frequency modulation. Both species are very loud to healthy human ears. On first hearing calls in the field we remarked on the song’s odd quality, perhaps a response to the rapid alternation of the two close harmonics. This would appear to be an instance of resonance stridulation. Yet the presence of the overmirror fold and a large terminal swelling blocking the basad terminus of the file, the lack of typical katydid count in file teeth: these are oddities of strigin morphology that suggest a differently functioning sound generator. See the Discussion for an attempt to imagine the workings of this strigin. The spectral peaks ( Fig. 30D ) are quite high-Q even though the pulses are comprised of only two dozen waves. Yet there is little or no transient distortion. Perhaps this is because the pulses build slowly and slowly decay ( Fig. 31 BC). “The amount of transient distortion varies as a function of the time required for the amplitude to rise from zero to maximum or to decay from maxiumum to zero. …slowly rising and slowly decaying signals are characterized by less transient distortion than signals for which the amplitude rises and decays very quickly” ( Speaks 1992 ).