Gwynnagraecia Rentz, Su and Ueshima, 2021

Rentz, Dcf, Su, You Ning & Ueshima, Norihiro, 2021, Studies in Australian Tettigoniidae: New short-winged Agraeciini from Australia (Orthoptera: Tettigoniidae; Conocephalinae; Agraeciini), Zootaxa 5059 (2), pp. 1-72 : 19-20

Gwynnagraecia Rentz, Su and Ueshima Gen. et sp. nov.

Type species: Gwynnagraecia viridis Rentz, Su & Ueshima gen. et sp. nov., here designated.

11 Named after our colleague Prof Darryl T Gwynne to celebrate his retirement.

Common name. Gwynne’s Katydids

Gwynnagraecia gen . nov. is proposed to accommodate three small micropterous species mostly from coastal Western Australia. The genus is unique in several characters. It is small as are many other Western Australian katydids in the Agraeciini as well as in the Tettigoniinae ( Oligodectoides . Rentz, Nanodectes Rentz , see Rentz (1985)) and the Microtettigoniinae ( Microtettigonia , see Rentz (2001)). Males have a peculiar extension of the tenth abdominal tergite (acting as pseudocerci?) and the titillators are largely unsclerotised. Females have a long, straight ovipositor and are wingless. The genus bears a superficial resemblance to Australiagraecia gen . nov., p. 8 but the cerci are very different from any of the species in that genus and no Australiagraecia gen . nov. species has modification of the tenth abdominal tergite.

In addition to the odd extensions of the tenth tergite mentioned above, males have an exaggerated, ice-tong-like cercus which apparently fits into a modified pocket ( Fig. 11J ) during copulation (exception G. marandoo Gen. sp. nov., see p. 22). Vahed et al. (2014) commented on cerci of similar structure in other tettigoniids. They observed copulations in at least 44 species of Tettigoniidae . During mating males transfer a spermatophore consisting of two parts, the ejaculate which contains the ampulla containing the sperm) and the spermatophylax, a white sticky substance containing highly nutritious ingredients that are said to be essential in the successful development of eggs. Females feed on the spermatophylax after separating from mating. Vahed et al. concluded that tong-like cerci are associated with transfer of ejaculate during copulation. It appears that katydids with reduced spermatophylaxes bear extraordinarily adapted clasping cerci that, as a result, seem to prolong copulation and prevent the female from feeding on the spermatophylax. Unfortunately, we have not observed any mating in Gwynnagraecia gen . nov. or Australiagraecia gen . nov. that could test these hypotheses. These katydids are common in their environment that similar experiments could be conducted to determine if the hypothesis is true for members of the Agraeciini . It would be revealing to test this hypothesis with G. marandoo gen. et sp. nov. the only known species in the genus that does not have an exaggerated ice-tong-like male cercus.

Gwynnagraecia gen . nov. superficially resembles Australiagraecia , gen. nov., p. 8, a taxon with many species in the southern portion of Australia, see p. 67. The species we describe here can be identified using the descriptions and comparing the morphological characters figured.

Generic characters.

Size small for tribe, form robust. Male macropterous, females apterous. Head not especially slanting ( Fig. 10D ), jaws not abnormally large; frons smooth, shining, not pitted or carinate ( Fig. 10C ), genae similar to frons; median ocellus minute, positioned on triangular frontal fastigium, lateral ocelli absent. Eye ovoid, very large, situated high on head ( Figs 10B, C ); frontal fastigium absent; fastigium of vertex short, stout, with minute median sulcus not projecting above antennal scape; scape large, produced quadrate on dorsal internal margin, pedicel very small, not modified; flagellum thread-like, slightly longer than length of body. Pronotum short, slightly raised, surface smooth, without carinae or pits; lateral lobe shallow, ventral margin feebly undulate, not swollen over thoracic auditory foramen; anterior margin of disk feebly concave, posterior margin truncate. Male tegmen extending for most of its length beyond apex of pronotum. Stridulatory file ( Fig. 20E, F ); tegmen without costa, subcosta arching, widely separated from media. Prothorax armed with a pair of elongate spines; meso- and metathorax each with prominent tube-like projections. All legs normal. All femora clothed with dark setae dorsally, ventral surface unarmed on both margins; fore tibia short, slightly swollen apically, dorsal surface unarmed, ventral margin with 6 spines on both margins, the distal two much smaller than the others; middle tibia cylindrical. but slightly swollen, dorsal surface armed on posterior margin with 2 spines positioned at the extremities of the middle third, ventral surface armed similarly to fore tibia ( Figs.10L ). Hind tibia armed apically with a pair of dorsal and ventral spurs ( Figs 10J, K ). Genicular lobes unarmed. Abdomen normal, without any prominent ridges or modifications except for genitalia ( Figs 10E, N ). Male tenth tergite extraordinary, an elongate curved tong projecting from each side, apex specifically modified; median incision absent, margin continuous; cercus massive, shaft straight, with apical ice-tong-like hook; titillators without any sclerotised portions; subgenital plate elongate, with median carina, styles elongate, median incision shallow. Female tenth tergite with narrow median incision; cercus fairly robust; subgenital plate triangular, apex acute. Ovipositor very elongate, much longer than length of body, gracefully upcurved, unarmed.

Overall colour in life bright green, shining; abdomen with a pair of faint, thin, parallel stripes over most of the dorsal surface.

Figures

FIG. 11. Gwynnagraecia perplexa. A. Adult male, dorsal view. B. Male, tip of abdomen, lateral view. Note extension of tenth tergite. C. Male, cerci and subgenital plate, ventral view. D. Male, tip of abdomen ventral view. E. Male, subgenital plate, ventral view. F. Male, left tegmen, dorsal view. G. Male tegmen, ventral view. Note stridulatory file. H. Male tip of abdomen, dorsal view showing structures in natural position. I. Female tip of abdomen, ventral view showing subgenital plate. J. Female, lateral view apical abdominal tergites. Note groove. K. Phallic complex. Note minute sclerites at base.

FIG. 10. Gwynnagraecia viridis. A. Adult male. B. Dorsal view head. Note fastigium of vertex. Holotype male, Nannup, W. A. C. Frons. Holotype male, Nannup, W. A. D. Head and pronotum, holotype male, Nannup, W. A. E. Tip of abdomen, subgenital plate removed to show tenth tergal extensions. F. Male tegmen, dorsal view. Kerragullen, W. A. G. Male tegmen, ventral view. Kerragullen, W. A. H. Male subgenital plate. Fitzgerald, National Park, W. A. I. Tip of abdomen, left view. Note extensions of tenth tergite. J. Right hind tibia, internal view. K. Right hind tibia, external view. L. Left middle tibia. Nannup, W. A. M. Phallic complex. N. Adult male, tip of abdomen, posterior view. Note position of extensions of tenth tergite.

FIG. 20. Stridulatory files. A. Australiagraecia spina holotype. B. Australiagraecia minuta. C. Ganiagraecia karwnia, Cytol. prep. 85-19. D. Ganiagraecia karwinia, S-363. E. Gwynnagraecia viridis, Kerragullen. F. Gwynnagraecia perplexa, Fitzgerald River. G. Latitatagraecia kalamaya, Cytol. prep. 2001-1. H. Latitatagraecia vulgivaga, Cytol. prep. 88-66. I. Cooloolagraecia wallum, paratopotype. J. Cooloolagraecia gubbi, paratopotype. K. Kokominiagraecia dicra, S-373. L. Coptaspis sp. 2. M. Timabarragraecia samneilli, paratopotype.