Description of two new species of Turanogryllini crickets (Orthoptera, Gryllidae, Gryllinae) from Cameroon, with identification keys for African species

During a Gryllidae survey in the Southern Cameroonian Plateau, two new species of the tribe Turanogryllini Otte, 1987 were discovered and described, namely Turanogryllus zamakoensis Um Nyobe, Kekeunou & Bilong Bilong sp. nov. and Neogryllopsis gorochovi Um Nyobe, Kekeunou & Ma sp. nov. This finding extends the known distribution of the genera Turanogryllus Tarbinsky, 1940 and Neogryllopsis Otte, 1983. New environments are also recorded for these crickets, and an identification key for African species is proposed for these two genera. Résumé Au cours d’une étude des Gryllidae dans le Plateau Sud Camerounais, deux nouvelles espèces de la tribu Turanogryllini Otte, 1987 ont été découvertes et décrites, à savoir Turanogryllus zamakoensis Um Nyobe, Kekeunou & Bilong Bilong sp. nov. et Neogryllopsis gorochovi Um Nyobe, Kekeunou & Ma sp. nov. Cette découverte élargie l’aire de répartition connue des genres Turanogryllus Tarbinsky, 1940 et Neogryllopsis Otte, 1983. De nouveaux environnements ont été également signalés pour ces grillons et une clé de détermination est proposée pour les espèces africaines de ces deux genres.


Introduction
Despite its central role in ecosystem functioning, biological diversity remains poorly known in some regions, especially for nonemblematic species such as orthoptera. In Cameroon, no detailed taxonomic study of crickets has been performed. Yet, crickets play several ecosystemic roles and are suitable bioindicators of the assessment of habitat quality and environmental change (Anso 2016). They form a major component of food webs (Capinera 2011, Wellstein et al. 2011, and some crickets are food for humans and some pets (Lavalette 2013, Rumpold andSchlüter 2013). Crickets can also be harmful to the environment (Bellmann and Luquet 2006). They attack most plants, but they are mostly seen on young plants that are not resistant to their injuries (Valdeyron 1955, Sikirou et al. 2018. Crickets from the tribe Turanogryllini Otte, 1987 belong to the field cricket subfamily Gryllinae Laicharting, 1781 (Chopard 1967, Tae-Woo 2012. This tribe includes four genera: Podogryllus Karsch, 1893;Turanogryllus Tarbinsky, 1940;Afrogryllopsis Randell, 1964;and Neogryllopsis Otte, 1983. Its monophyly, however, has not been confirmed by the recent phylogenetic study of Chintauan-Marquier et al. (2016). Their taxonomy and distribution have yet to be clearly established, and several new species remain undescribed.

Materials and methods
This study was conducted in closed (forests) and open (fields and/or fallows) environments of three localities in the southern Cameroonian plateau: Zamakoe, Ongot, and Ngutadjap (Fig. 1). The characteristics of each study locality can be found in the publication of Um Nyobe et al. (2021). In these habitats, crickets were captured from March 2014 to September 2015 using pitfalls and quadrats, according to the methodology described in Um Nyobe et al. (2021).
The captured specimens were stored in 70% ethanol and transported to the zoology laboratory of the University of Yaoundé I for further studies.
Observations of morphological characters were performed using a binocular magnifier (Leica) connected to an Amscope camera (Heerbrugg brand). Pictures of the external morphology of specimens immersed in 70% ethanol were taken using an LCD Digital Microscope connected to a computer. Measurements were taken using a NEIKO electronic caliper. Male genitalia were dissected and then cleaned with 5% KOH and ethanoic acid for 8 hours and 30 minutes, respectively (Vasanth 1993, Um Nyobe et al. 2021). Imaging of male genitalia was made using an AmScope MU1000 digital camera or a Canon EOS 40D Digital SLR camera. To highlight the structural components of male genitalia, a water solution containing a drop of JBL Punktol was used. To fix orientations and stabilization of genitalia for photography, a clear and viscous hand sanitizer was used, following Su (2016).
Abbreviations used in genitalia identification. -Desutter (1987), Randell (1964), and Otte et al. (1988) used different terms for the same genital structures. Although we realize that there is a need to have a unified terminology system that does not currently exist, we chose to use the terminology for male genitalia adapted from Randell (1964) and Otte et al. (1988) because they explicitly described the structure of the male genitalia of the type species of the genera Turanogryllus and Neogryllopsis, which allows direct comparisons between the new species and the other species previously described in these genera. We indicate the terms corresponding to the terminology from Desutter (1987)      large; face entirely pale below median ocellus and below level of antennae (Fig. 2C). Pronotum covered with very fine pubescence, without bristles; dorsum dark brown, muscle attachment plates pale brown ( Fig. 2A); lateral lobes ivory, becoming dark brown at upper margin (Fig. 2B). TI and TII ivory-colored; TI with a large outer tympanum. Hindlegs: f FIII pale brown with faintly darker oblique stripes on outer surface; darker around knees, especially on inner surface; TIII pale brown with 6 inner and 7 outer subapical spurs. FWs with square base, reaching abdomen mid-length; its length to pronotal length ratio ca. 2.5; dorsum brown; lateral field pale, dark brown between upper three veins. Stridulatory file with 156 teeth; harp with 3 oblique veins; mirror oval, with one dividing vein (Fig. 2E). Hind wings short, hidden by FWs. Abdomen dorsum dark brown; venter pale; cerci pale. Male genitalia (Fig. 3): lateral lobes of epiphallus with styli at their posterior extremities, and these styli are provided with bristles;

Taxonomy
dorsal lobes of ectoparameres lamelliform, curved dorsally in its posterior half; ventral lobes of ectoparameres digitiform, sigmoidally curved; dorsal lobes of ectoparameres enlarged above ventral lobes of ectoparameres. Female. Similar to male but occiput with 6 fine, wellindividualized brown stripes; FWs short, overlapping slightly and with rounded ends (Fig. 2D).  brown spots in middle of inner and outer surfaces. TIII 0.63-0.68 times as long as FIII; with 4 or 5 inner and 4 to 6 outer subapical spurs. Cerci very pale. Females. Similar in coloration to males. Apterous. Ovipositor as long as or longer than FIII.  4A); top of head without dark markings along inner margins of eyes; forehead dark brown, without white stripe between lateral ocelli; cheeks pale brown (Fig. 4B) and face brown before epistomal suture and pale after this suture (Fig. 4C). Pronotum red-brown without ivory-colored band along margins (Fig. 4A). TI and TII pale, somewhat orange. Hindlegs: FIII with distinct oblique brown stripes on outer surface; TIII pale brown with 5 inner and 5 outer subapical spurs. FWs: dorsum grayish brown, lighter on lateral field; FW length to pronotal length ratio c. 2.3 mm; stridulatory file with 86 teeth; harp with 4 oblique veins; mirror round without a dividing vein; apical field very small (Fig. 4E). Hind wings absent. Abdomen: Tergites dark brown, with pale posterior margins; venter light brown; cerci dark brown. Male genitalia (Fig. 5): Epiphallus well developed but short; lobes of epiphallus in posterior view long, tapering, two points closely apposed, separated by a deep cleft; lateral lobe of epiphallus with long setae near base and without spines; ectoparamere without setae.

Neogryllopsis gorochovi
Female. Similar to male in color. Size range extends considerably above that of male (Table 1). FWs very short, sometimes just visible under edge of pronotum (Fig. 4D).

Discussion
We described two new species belonging to the genera Turanogryllus and Neogryllopsis, respectively. Both are newly recognized for Cameroonian fauna; they increase the number of African species of Turanogryllus to 11 and of Neogryllopsis to 21.
It is worth noting that all species of the genus Turanogryllus have TI with small inner and large outer tympanum (Tarbinsky 1940), while those of the genus Neogryllopsis have divided mirrors (Otte 1987). Nevertheless, T. zamakoensis sp. nov. has only one outer tympanum, and N. gorochovi sp. nov. has an undivided mirror as found in Neogryllopsis storozhenkoi Gorochov, 1988(Otte et al. 1988. The description of these two new species of Turanogryllini from Central Africa (more precisely, from Cameroon), extends the known range for both genera. In addition, they were previously known as field crickets (Randell 1964, Otte 1983, Otte 1987, Otte et al. 1988) but in the current work, T. zamakoensis sp. nov. was captured in a forested area,while N. gorochovi sp. nov. was found in both open and closed environments. It is possible that T. zamakoensis and N. gorochovi also occur in open areas near forests. To better characterize the species' living environments, additional studies are needed.