Afroanthracites nguru, Hemp & Ingrisch & Heller, 2017

Hemp, Claudia, Ingrisch, Sigfrid & Heller, Klaus-Gerhard, 2017, A new genus and other new species of Agraeciini from the Eastern Arc Mountains, East Africa (Orthoptera: Tettigoniidae; Conocephalinae; Agraeciini), Zootaxa 4311 (1), pp. 1-22 : 17-20

AfroanthraciteS nguru n. sp. Hemp C.

http://lsid.speciesfile.org/urn:lsid: orthoptera .speciesfile.org:TaxonName:497467

Holotype, male, Nguru Mountains , forest above Turiani, February 2017. Depository: MfN . 1 female, same data as holotype. Depository MfN . Further paratype material: 5 males, 4 females, same data as holotype, March and June 2017 .

Description male. General colour predominantly green with broad brown fascia with short lateral black stripes on both sides on dorsum of pronotum bordered by broad white fascia. On 10th abdominal tergite large yellow to orange patch. Joints of legs and tarsi white to tawny. Venter of abdomen orange ( Fig. 24 ). Head and antennae. Fastigium verticis conical, slightly shorter than scapus. Face uniformly green, labrum tawny. Antennae long, more than twice the length of body (> 6 cm), first two segments green, next 10 or more segments black, the turning reddish to tawny. Thorax. Pronotum rugose, rounded, posterior area (in metazona) slightly inflated. Tegmina hidden for most of their length under pronotum only straight white hind margin of tegmina visible. Legs. Fore coxa with stout spine. Fore and mid femora only with 3–4 inner ventral spines, hind femur with 6 outer spines, unarmed on inner side. Fore and mid tibiae with double row of 5–6 irregular set ventral spines and pair of ventral spurs. Hind tibiae with 3 rows of densely set small spines and one long spur on each side ventrally and pair of short curved spurs dorsally. Abdomen. Tenth abdominal tergite at posterior margin incised, forming two broadly rounded lobes ( Fig. 25 B). Subgenital plate elongated, posteriorly up-curved and little incised medially, with short styli. Cerci white, stout with two short branches at tips ( Fig. 25 B).

Female. Similar to male in size and colour pattern ( Fig. 24 ) with green and white mottled face and light brown mandibles ( Fig 27 ). Patch on 10th abdominal tergite not as large and conspicuous as in male but narrow and whitish. Ovipositor slightly up-curved ( Fig 28 A). Subgenital plate broad with strongly incurved posterior margin ( Fig. 28 B).

Measurements, male (mm) (N = 4). Body length 26.5–27.3. Length of pronotum 9.1–9.9. Length of hind femur 13.1–14.1.

Measurements, female (mm) (N = 4). Body length 23.8–29.1. Length of pronotum 7.7–8.0. Length of hind femur 14.5–15.2. Ovipositor 11.4– 11.6.

Song. Calling song composed by echemes following each other at relatively variable intervals of about 970±375 ms (n=30). Echemes consisting of 6±0.6 (n=32) syllables produced at a rate of 37 Hz (range 32.2–41.7 Hz; n= 32; T=22°C; Fig. 10 ). Echemes presented in loose sequence or in groups of 4±1 (inter group intervals 25 ± 16 s; n=15). The spectrum of the song is broad-banded with a maximum at about 14 kHz ( Fig. 11 ).

Habitat. Submontane closed forest. Understory dweller found at night in trees and bushes.

Distribution. Tanzania, Nguru Mountains.

Etymology. Named after the Nguru Mountains.

Diagnosis. Except for A. uluguruensis Hemp & Ünal, 2013 all other male Afroanthracites species have differently shaped 10th tergites—either without an incision at the posterior end ( A. usambaricus (Sjöstedt, 1913) , A viridis Hemp, Ingrisch & Ünal, 2013 , A. lutindi Hemp, 2015 ), narrow elongated with an indentation at the posterior tip ( A. jagoi Ünal & Hemp, 2013 ), or with a median furrow ( A. discolor Hemp, Ingrisch & Ünal, 2013 , A.

pseudodiscolor Hemp, 2015 ). In A. uluguruensis the lobes of the 10th abdominal tergite are not as broad as in A. ngologolo n. sp. and A. nguru n. sp. and the overall colour pattern, especially on the pronotum is different. The cerci between the three morphologically very similar species are slightly different in their shapes. Also song differs between the three species. The colour pattern is generally very stable in Afroanthracites and thus a good identification tool. Also most Afroanthracites species are restricted to certain mountain areas as is the case with A. ngologolo n. sp. (Udzungwa Mountains) and A. nguru n. sp. (Nguru Mountains). Females are very similar but also exhibit the typical colour pattern. Female A. nguru n. sp. has a broad subgenital plate with a broadly incurved posterior margin while A. ngologolo n. sp. has a subgenital plate with a even more strongly incurved posterior margin so that almost two lobes are formed.

Figures

FIGURE 10. Oscillograms of the calling songs of D. amaniensis n. sp., D. octopunctata n. sp. and Afroanthracites nguru n. sp.

FIGURE 11. Power spectra of the calling songs of D. amaniensis n. sp., D. octopunctata n. sp. and Afroanthracites nguru n. sp.

FIGURE 24. Male Afroanthracites nguru from closed forest of the Nguru Mountains.

FIGURE 25. Morphological details of male A. nguru n. sp. Abdominal apex lateral view (A) and dorsal view (B).

FIGURE 27. Female A. nguru n. sp. with green-white mottled face and brown mandibles.

FIGURE 28. Ovipositor (A) and subgenital plate (B) of female A. nguru n. sp.