Dioncomena magombera Hemp, 2023

Hemp, Claudia, Montealegre-Z, Fernando, Woodrow, Charlie & Heller, Klaus-Gerhard, 2023, Bush-crickets with very special ears and songs - review of the East African Phaneropterinae genus Dioncomena Brunner von Wattenwyl, 1878, with notes on its biogeography and the description of new species, Deutsche Entomologische Zeitschrift 70 (2), pp. 221-259 : 221

Dioncomena magombera Hemp sp. nov.

Figs 1G-I , 2C , 3G, H , 4E, F , 7 , 19 , 21 , 22F, G , 26B-D , 30 , 36

Type material.

Holotype male. Tanzania, Udzungwa Mountains, Mangula Gate, lowland wet forest, 7°50'38"S, 36°53'08"E, 340 m, January 2016. Depository: CCH.

Paratypes: all Tanzania; 3♀♀, same data as holotype and March 2016. 1♂, 3♀♀, Magombera Forest Reserve, lowland forest, 7°49'10"S, 36°58'42"E, 280 m, January 2019. 2♀♀, Kihansi Forest Reserve, area between 8°36'35"S, 35°51'08"E, 370 m and 8°35'48"S, 35°50'59"E, 800 m, lowland to submontane forest, January 2016. 1♀, Kanga Hill, Nguru Mountains, 5°59'04"S, 37°45'36"E, 420 m, riverine vegetation, March 2022; 1♂, 4♀♀, Kimboza Forest Reserve, Morogoro Region, 200-300 m a.s.l., 7.03°S, 37.78°E, disturbed lowland forest, March 2022. 1♀, Miombo woodlands, Msaze near Gulwe, Mpwapwa District, 6°31'21"S, 36°22'15"E, 1000 m, May 2022. Depository: CCH.

Description.

Male. Typical Dioncomena in habitus and size, with contrasting green, bluish, and black colors (Fig. 1G, H ). Head. Fastigium of vertex compressed, sulcate above. Thorax & legs. Pronotum with slightly inflated posterior part of lateral lobes. Broad black stripe with fine median green line on pronotal disc, widening at metazona. Fore coxa brownish or black with broad-based short yellow spine. Fore and mid femora with double row of small ventral spinules, hind femur with widely spaced irregular positioned spines. Fore tibia with ventral double row of irregular set small spinules and a pair of short ventral spurs; dorsal inner side with short spine below tympanum and 1-3 short black spines along length. Mid tibiae with ventral double row of hooked black spinules and spurs, dorsal on mid tibiae at apical part with few hooked black spines. Tegmina & wings. Typical shape and coloration for Dioncomena , with continuous stridulatory file on left tegmen (Fig. 2C ). Abdomen. Tenth abdominal tergite incurved at posterior margin with shallow membranous structure medially. Cerci green and stout, with black inwardly hooked tips (Fig. 3G ). Subgenital plate longer than wide, v-shaped incurved medially (Fig. 3H ).

Female. Similar habitus, size, and coloration as male (Fig. 1I ). Ovipositor long and slightly upcurved (Fig. 4E ). Subgenital plate narrow and triangular with evenly curved posterior margin (Fig. 4F ), without hooked spines on mid tibiae.

Nymphs. Similar to the adults. Fig. 7 shows the last instar of a female D. magombera sp. nov.

Measurements, (mm) males (n = 3). Body length 16.8-25.0. Length of pronotum 3.6-4.0. Length of tegmina 22.5-25.1. Length of hind femur 18.2-19.3

Measurements, (mm) females (n = 6). Body length 14.5-17.8. Length of pronotum 5.4-6.9. Length of tegmina 22.4-27.5. Length of hind femur 18.7-21.7. Ovipositor 5.4-6.9.

Habitat and distribution.

Lowland to submontane forest. Mostly found singularly in understory vegetation of closed forest. Distributed in Tanzania’s Udzungwa, Uluguru, and Nguru Mountains, as well as Miombo woodlands in the Mpwapwa District.

Etymology.

Named after the Magombera Forest Reserve at the Udzungwa Mountains’ foothills near Mangula, where the first specimens were collected. Noun in apposition.

Remarks.

Ragge (1980) reported two female Dioncomena jagoi individuals from Kimboza Forest Reserve at the Uluguru Mountains’ foothills. Our team’s specimens collected in March 2022 from the same location belong to the new species D. magombera . A female specimen captured at the Nguru Mountains’ foothills and another in Miombo woodlands in the Mpwapwa District near Gulwe also belong to this species, indicating D. magombera sp. nov. is widespread in lowland forests along the southern branch of the Eastern Arc Ranges. Two female specimens listed by Ragge (1980) from Kimboza Forest Reserve were studied in the Natural History Museum London and found to belong to D. jagoi , labelled as paratypes by David Ragge. Further collecting is necessary to determine whether two Dioncomena species of the Dioncomena jagoi -group exist in Kimboza Forest Reserve, and studies on their song must be undertaken.

Figures

Figure 1. Dioncomena species of the D. jagoi - group: A-C. Male (A, B) and female (C) of D. jagoi, East Usambara Mountains; D, E. Male (D, E) and female (F) of D. flavoviridis sp. nov.; G-I. Male (G, H) and female (I) of D. magombera sp. nov.; J-L. Male (J, K) and female (L) of D. sanje sp. nov.

Figure 2. Stridulatory files of Dioncomena species, tegmen articulation to the right. A-E. D. jagoi - group: A. D. jagoi; B. D. flavoviridis sp. nov.; C. D. magombera sp. nov.; D. D. sanje sp. nov.; E. D. grandis (from Naskrecki and Guta 2019); F. D. ornata (Nguru Mts.); G. D. zernyi; H. D. tanneri; I. D. versicolor sp. nov.; J. D. ngurumontana sp. nov.

Figure 3. Male apices of the Dioncomena jagoi - group. A, B. Dorsal (A) and ventral (B) view of D. jagoi; C, D. Dorsal (C) and ventral (D) view of D. sanje sp. nov.; E, F. Dorsal (E) and ventral (F) view of D. flavoviridis sp. nov.; G, H. Dorsal (G) and ventral (H) view of D. magombera sp. nov.

Figure 4. Female Dioncomena species. A, B. Ovipositor and subgenital plate of D. jagoi; C, D. Ovipositor and subgenital plate of D. flavoviridis sp. nov.; E, F. Ovipositor and subgenital plate of D. magombera sp. nov.; G, H. Ovipositor and subgenital plate of D. sanje sp. nov.

Figure 7. Last instar of female Dioncomena magombera sp. nov., distinguished by its long ovipositor from D. sanje sp. nov. which occurs syntopically.

Figure 19. Oscillograms of male calling songs of Dioncomena species. Overview (150 - s-sections).

Figure 21. Oscillograms of male calling songs of Dioncomena species. Central portion of main part of song; 20 - s-sections.

Figure 22. Oscillograms of male tick songs of Dioncomena species. A-C. D. flavoviridis; A, B. ticks; C. alternating males; D. D. jagoi; E. D. grandis (from Naskrecki and Guta 2019); F, G. D. magombera sp. nov.; H, I. D. sanje sp. nov.; J-L. D. ornata; M. D. zernyi; N. D. tanneri; O. D. versicolor sp. nov.; P. D. ngurumontana sp. nov.

Figure 26. Oscillograms of male calling songs of Dioncomena species. Detail (3 - s-sections). A. D. jagoi; B-D. D. magombera sp. nov.; E, F. D. zernyi; G, H. D. tanneri; I, J. D. versicolor sp. nov.

Figure 30. Power spectra of the male calling songs of the Dioncomena species studied. Asteriks in the respective color mark the positions of the analysed sounds, for D. flavoviridis sp. nov. in Fig. 23, for D. jagoi in Fig. 20, for D. magombera sp. nov. in Fig. 25, for D. sanje sp. nov. see Figs 26, 29 (dense combination: blue and violett, high frequency syllable: green, gappy combination: red), for D. ornata in Fig. 27, for D. zernyi in Fig. 25 E (song), Fig. 21 M (ticks), for D. tanneri in Fig. 25, for D. versicolor sp. nov. in Fig. 25, for D. ngurumontana sp. nov. in Fig. 23.

Figure 36. Distribution of Dioncomena species in East Africa. Locality data this paper, Ragge 1980; Hemp 2017; Massa 2021; Naskrecki and Guta 2019. Source: Google maps.