Paraplangia sinespeculo Heller

Heller, Klaus-Gerhard, Hemp, Claudia, Massa, Bruno, Kocinski, Maciej & Warchalowska-Śliwa, Elzbieta, 2018, Paraplangiasinespeculo, a new genus and species of bush-cricket, with notes on its biology and a key to the genera of Phaneropterinae (Orthoptera: Tettigonioidea) from Madagascar, Journal of Orthoptera Research 27 (2), pp. 143-153 : 146-149

Paraplangia sinespeculo Heller sp. n.

Material examined and depository.-

Holotype ♂, allotype ♀ and 1 paratype ♂. All pinned, original labels "MADAGASCAR: Mitsinjo Forest Reserve, near Moramanga (18°57'S, 48°13'E), 1 i - 31 xii 2014, coll. Giesse". "Holotype Paraplangia sinespeculo " [red handwritten label]. Holo- (CH8239) and allotype (CH8241) in Museum für Naturkunde, Berlin, Paratype (CH8240) in Collectio Heller. One hind leg of CH8240-1 separate in pure ethanol in Collectio Heller.

Sound files are deposited at OSFO and bio.acousti.ca (see also Suppl. materials 1, 2).

Measurements.-(In mm) Males. Body length: 27.5-28.2; pronotum length: 6.8-7.4; pronotum height: 6.9-7.0; hind femur: 19.5-20.0; hind tibiae: 21.9-23.5; tegmina: 43.2-43.8; length of hind wings: 46.4-46.6; tegmina width: 14.3-14.7. Female. Body length: 29.9; pronotum length: 7.8; pronotum height: 7.0; hind femur: 20.9; hind tibiae: 22.0; tegmina: 43.6; length of hind wings: 47.6; tegmina width: 17.2; ovipositor 13.0.

Diagnosis.-

As for genus (sole species).

Description.-

Male. Habitus and color: Large bush-crickets, predominantly green with a weak yellow mid line on head and pronotum (Fig. 1; not visible in dried specimens). Anterior (costal) edge of tegmen in basal half to two thirds with white spots. Head, pronotum and thoracic sternites (Fig. 2) as for genus.

The stridulatory area of the left tegmen green, with distinct but not elevated stridulatory vein (Fig. 3A), of right tegmen weakly green or white, with several irregular veins, without glossy mirror (Fig. 3B). The stridulatory vein beginning at the distal end with a series of ca. 15 small teeth, increasing slowly in size. At the same place, the file starting to be elevated above the tegmen level. Having reached the highest point, there are ca. 10 widely spaced large teeth. After five of them, tooth size and spacing continuously decrease again. The file then ends in about 10 small to very small teeth (Fig. 3D).

Fore coxae armed with a long spine. Fore femora unarmed, fore tibiae with 2-3 inner ventral spines and 3 distal ones, superiorly mainly flat (see above). Mid femora with 2 very small spinules, mid tibiae ventrally with about 7 spines each on outer and inner side. Hind femora distally with about 7 outer and 2-4 inner ventral spines, hind tibiae straight, longer than femora, in cross-section square, with many spines on all four edges (about 15 on each ventral, about 25 on each dorsal side).

Abdomen.-

Subgenital plate long, tapering into a deeply incised caudal part, bearing long styli (Fig. 4A). Cerci relatively long, slightly in-curved at tip, with a short, strong, hook-like outer and a rounded inner spine (Fig. 4 A–B). No sclerotized titillator.

Female.-

Color and general habitus like male. Ovipositor as described for genus (Fig. 5A-B). Subgenital plate short, triangular and at apex slightly incised, side sclerites with strong and incurved lower edge (Fig. 4C), probably the anchor point for the male cerci during mating.

Derivatio nominis.-

Sinespeculo (Latin = without mirror). To be treated as noun in the nominative singular.

Eggs.-

Mature eggs were taken from the female after her death and preserved in ethanol. They show the flat, ovoid shape, typical for phaneropterines (length 5.7 ± 0.2 mm, width 2.75 ± 0.06 mm, n = 4; Fig. 1B). The collector wrote "we found the eggs under leaves".

Nymphs.-

The specimens were obtained as relatively small nymphs (probably stage 2 or 3). At that time they were nearly completely green with few brown markings (not looking like the small nymphs of Plangia satiscaerulea ; see Hemp in preparation). Soon they showed a yellow midline running from head to mid of abdomen and they developed a brown pattern at the back of the abdomen, similar to that seen in older Eurycorypha nymphs (Hemp in preparation; Fig. 1 C–E). The pronotum had a middle keel like the adults in Tropidonotacris Chopard, 1954 ( Hemp et al. 2014) or Pelecynotum Piza, 1967 (OSFO). The males became adult at 9th and 13th May, the female slightly later, at 20th May. The female died on 30th June due to an infection with Nematomorpha and all were prepared.

Acoustics.-

The male calling song consisted of song units, repeated in interval of many minutes as long as the female did not respond. Each song unit (163 recorded) contained two series of syllables, the first with 10.7 ± 1.0 syllables (mean ± SD; range 8-12; n = 21), the second only with 4.2 ± 0.9 (range 3-5; Fig. 6). The second series started 9.3 ± 0.7 s (range 8.3-10.7 s) after the beginning of the first and both series were separated by a silent interval of 4.2 ± 0.4 s (range 3.7-5.3 s). The intervals between the syllables ranged from 400 to 619 ms (487 ± 66 ms), measured in the second half of the first series. In amplitude modulation, both series were decrescendo or without change in loudness. The syllables were very short, less than 5 ms (Fig. 7A), consisting of few, often hardly separable impulses.

Like in most phaneropterines ( Heller et al. 2015), the female that was ready to mate reacted to the male song with its own acoustic signals. It always answered after or at the end of the second series. The first response syllable of its response was registered 2.7 ± 0.6 s after the beginning of the second male series (range 1.7-4.2 s; n = 74) and 0.55 ± 0.33 s after a male syllable (range 0.04-2.8 s; n = 73). The female response was quite variable; the simplest answer consisted of one impulse, but she could also make two impulses at relatively large intervals, long (about 8) series of impulses with short intervals or mixtures with many impulses at varying intervals (Fig. 6 B–C; see Suppl. materials 1, 2: duets 1 and 2).

The carrier spectrum of male and female song is relatively narrow-banded with its maximum at about 8.4 ± 0.7 kHz (n = 3; range 10 db below peak 7.3-10.2 kHz) in the male and 8.7 ± 0.2 kHz (n = 3; range 10 db below peak 6.9-10.9 kHz; Fig. 7) in the female.

Mating behavior.-

Both males (body mass 1178 mg and 1236 mg) copulated with the female (body mass 2536 mg, 2528 mg) at an interval of 3 days (21st and 24th June). They mated in the morning (about 9:00-10:00; they were placed together the evening before, but did not mate) with mating durations of a few minutes and transferred spermatophores of 130 and 151 mg (mean of male loss and female gain), thus about 12% of the male body mass. They were slightly smaller than in Plangia multimaculata (17%; Hemp et al. 2015). Both spermatophylaces showed relatively irregularly formed central parts protruding anteriorly, in addition to the symmetrical lateral basal parts (Fig. 8).

Chromosomes.-

Both analyzed species, the African Paraplangia sinespeculo and Orophus cf. tessellatus from Costa Rica, showed a diploid chromosome number of 2n = 31 karyotype in the male with an X0 and 32 in the female ( O. cf. tessellatus ) with XX sex determination system. Fifteen pairs of acrocentric chromosomes gradually decreased in size; the sex chromosome (X) was the largest element in the karyotype (Fig. 9A-D). After FISH with 18S rDNA, silver staining, and C-banding, the results demonstrated coincidence between the localization of major ribosomal genes and active NOR as well as the position of C-bands. In individuals of both species, a single large rDNA cluster per haploid genome was detected, located on the first pair of autosomes near the distal region (Fig. 9B - left corner) and active NOR (Fig. 9B) as well as C-band (Fig. 9A). In contrast, in Orophus cf. tessellatus , FISH revealed a paracentromeric signal on the fourth pair of autosomes (Fig. 9D) coincident with thick C-bands (Fig. 9C) and active NOR (not shown). The signals produced by FISH with the (TTAGG)n probe were stronger in O. cf. tessellatus (Fig. 9D) than those observed in P. sinespeculo (hardly visible).