Parahabetia pictifrons obtusa Ingrisch, 2021

Parahabetia pictifrons obtusa Ingrisch, 2021 View in CoL

( Figs 59–64 View FIGURE 59 View FIGURE 60 View FIGURE 61 View FIGURE 62 View FIGURE 63 View FIGURE 64 )

Material studied. Holotype male: Papua New Guinea, Morobe, McAdam National Park, Bulolo Gorge , 7°16’ S, 146°38’ E, 28 viii 1981, leg. G.K. Morris, (Depository NBC, Leiden); paratype male female same data as holotype. GoogleMaps

Measurements. (Length in mm) (male n = 2 & holotype after Karny in parens, female n = 1): body male 22.5–23 (24), female 27; pronotum male 6.5–6.6 (7.5), female 6.5; elytron male 18.2–18.5 (19.5), female 20; hind femur male 14–14 (16), female14.5; ovipositor 12.

Comments. Ingrisch in revising Parahabetia , names these Bulolo Gorge specimens ( Ingrisch 2021) as a new subspecies of Parahabetia pictifrons . The name obtusa refers to the shape of the tips of the triangular rearward projections of the 10 th abdominal tergite: their bluntness distinguishes from P. p. acuta.

In life the frons is a conspicuous blue green, as also the antennal scapes ( Fig. 59 View FIGURE 59 ). Facial colours of this sort may be adaptive in concealing the insect from colour-vision predators such as birds: as the insect faces skyward legs extended, its coloured markings blend into the colours of bromeliad leaves used as a daytime refugium. The pronotum in dorsal aspect ( Fig. 61A View FIGURE 61 ) shows conspicuously broadened lateral lobes (bullae) at the entry to the acoustic stigma, an adaptive acoustic feature.

Stridulatory file. Male stridulatory file tiny ( Fig. 63 View FIGURE 63 ), shortest distance between most proximal and distal tooth 1.2 mm, greatest width of teeth 0.075 mm; of usual shape, slightly fusiform with proximal and distal parts curved and faintly sinuate in profile; total number of teeth 136 of which 89 are apparently functional and regularly spaced, 19 teeth per 0.25 mm.

Stridulation. A resonant stridulation, judging by the simple ultrasonic high-Q sine wave at 34 kHz ( Figs 64C, D View FIGURE 64 ). Also there is no suggestion of elastic uncoupling apparent in this single sustained pulse ( Fig. 64. B View FIGURE 64 ). The insect repeats these 4-ms pulses at a regular period of just under 50 ms ( Fig. 64A View FIGURE 64 ). Each call is comprised of>140 waves which the number of apparently functional teeth—89 (see above)—is inadequate to explain as a ‘one wave per file tooth event’. Something on the insect’s wing is oscillating making a simple wave train at one 34 kHz frequency. How is this possible unless more than one wave is associated with each tooth?