Afroanthracites inopinatus, Hemp & Heller, 2019

Hemp, Claudia & Heller, Klaus-Gerhard, 2019, New Agraeciini species from the Eastern Arc Mountains, East Africa (Orthoptera: Tettigoniidae; Conocephalinae; Agraeciini), Zootaxa 4664 (3), pp. 301-338 : 306

Afroanthracites inopinatus n. sp. Hemp C.

( Figs. 7 , 8 A , 9 A, B , 39 , 42 , Table 1 )

Holotype: male. Tanzania, South Pare Mountains , Mt Mwala, 1600–1700 m, montane forest, December 2017 . Paratype female, same data as holotype but March 2019. Depository: collection C. Hemp .

Further paratype material: 4 males, 5 females, 2 male nymphs, 1 female nymph, same data as holotype and December 2017 and November 2018. 1 male, South Pare Mountains , Kwizu Forest Reserve, montane forest, June 2018. Depository: collection C. Hemp .

Description. Male. General colour predominantly whitish to light brown and green ( Fig. 7 A ). On dorsum of pronotum in area of metazona brown patch bordered by cream-white fasciae. Head brown, face green, area around scapi black. Abdomen dirty white to light brown. Legs green with herringbone pattern on outer side. Head and antennae. Fastigium verticis conical, shorter as scapus. Labrum and mandibles orange. Antennae thick, long, more than twice the length of body, scapus blackish, second antennomere also black, remaining antennomeres of reddish colour. Thorax. Pronotum rugose, rounded, posterior area (in metazona) slightly inflated. Tegmina hidden for most of their length under pronotum only straight hind margins of tegmina visible. Width of the mirror (see Hemp et al. 2015) in the left tegmen 1.64 mm, its length 1.15 mm. Fore coxa with short and curved spine. Fore and mid femora with 2–3 outer stout ventral spines, unarmed on inner side. Hind femur with 4 stout ventral spines distally on outer side, inner side unarmed. Fore and mid tibiae with ventral double row of 4–5 spines and a pair of ventral spurs similar to other spines on tibiae. Hind tibiae with four rows of spines, distally more densely set; dorsally 1 pair of spurs, ventrally 2 pairs. Abdomen. Tenth abdominal tergite elongated, forming at posterior end two broad and rounded lobes. Anterior part of 10 th abdominal tergite blackish, posterior part green ( Fig. 8 A ). Subgenital plate elongated, processes posteriorly up-curved and v-shaped incised medially, with finger-like styli as typical for Afroanthracites . Cerci laterally compressed with a blunt edge midway and two short processes at its tip ( Fig. 8 A ).

Female. Similar to male but larger ( Fig. 7 B ). Face as male. Brown patch on metanotum of pronotum not as large as in male and rather inconspicuous. Venter of abdomen whitish. Ovipositor stout, of reddish colour, slightly up-curved ( Fig. 7 B ). Posterior margin of 10 th abdominal tergite medially deeply incised and thus forming two lobes ( Fig. 9 A ). Subgenital plate medially deeply u-shaped incised ( Fig. 9 B ).

Nymphs. As in A. montium from the Mt Kilimanjaro area and A. usambaricus from the West Usambara Mountains. Nymphs of A. inopinatus n. sp. have two black to light grey (sometimes obsolete) stripes on the face.

Measurements, male (mm) (N = 4). Body length 19.4–21.4. Length of pronotum 7.4–7.6. Length of hind femur 10.3–10.5.

Measurements, female (mm) (N = 4). Body length 17.5–24.4. Length of pronotum 5.5–6.0. Length of hind femur 11.0–11.8. Ovipositor 8.5–9.6.

Song. All recorded males (from Mt Mwala and Kwizu Forest Reserve) produced fast sequences of disyllabic echemes (occasionally also consisting of one or three syllables). See Fig. 39 , 42 and Table 1 for details.

Diagnosis. Morphologically closely related to A. montium from the Mts Meru and Kilimanjaro area and A. usambaricus restricted to the West Usambara Mountains. All three species share a similar colour pattern with a brown patch on the metazona of the pronotum bordered by white to cream fasciae and have also quite similar songs (see Hemp et al. 2015). The abdomen may be uniformly bright green to whitish-light brown or green with some dark mottles in A. usambaricus . Males of all three species have an elongated 10 th abdominal tergite, broad and dark coloured at its anterior part, then narrowing with a black fascia along its lateral edges, medially of green colour and at their tips divided into two lobes ( Fig. 8 A–C). Also the cerci are similar consisting of a curved stout main branch ending in two short processes ( Fig. 8 A–C). Differences are found in the stoutness of the 10 th abdominal tergites (compare 8 A–C) and slight differences in the shape of the male cerci (compare Fig. 8 A–C). All three species are restricted to forests of the respective areas. Females are morphologically also very similar with a similar colour pattern as the males but with the pronotal brown patch not as large and conspicuous. Clear differences are found when comparing the subgenital plates of the females. A. inopinatus n. sp. has a deeply u-shaped incised subgenital plate while in A. usambaricus only a small u-shaped incision is typical. In A. montium the subgenital plate is v-shaped incised medially (compare Fig. 9 B, D, F ). Only in nymphs of these three species parallel dark fasciae are present on the face also supporting a close relationship.

Distribution. Restricted to submontane and montane forests of the South Pare Mountains.

Etymology. From Latin:— inopinatus , unexpected since it was a surprise to find yet another Afroanthracites species in the Eastern Arc Mountains morphologically related to A. montium and A. usambaricus .

Figures

FIGURE 7. A. Male Afroanthracites inopinatus n. sp. B. female A. inopinatus n. sp.

FIGURE 8. Male Afroanthracites apices, dorsal view. A. A. inopinatus n. sp. B. A. usambaricus, West Usambara Mountains C. A. montium, Kilimanjaro, inset: left cercus.

FIGURE 9. Apices of female Afroanthracites species: A, B. A. inopinatus n. sp., dorsal view (A) and subgenital plate (B) C, D. A. usambaricus, dorsal view (C) and subgenital plate (D) E, F. A. montium, dorsal view (E) and subgenital plate (F).

FIGURE 39. Oscillograms of the calling song of Afroanthracites species.

FIGURE 42. Power spectra of the calling song of Afroanthracites, Afroagraecia and Dendrobia species. In A. guttatus the restricted frequency range is marked by a black line at its end.