Dioncomena sanje 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

publication ID	https://dx.doi.org/10.3897/dez.70.100804
publication LSID	lsid:zoobank.org:pub:2824CBF6-C72A-4397-B944-262D324AF5D6
persistent identifier	https://treatment.plazi.org/id/491B0F5E-501E-4F8B-89AE-184A3CA2CB3E
taxon LSID	lsid:zoobank.org:act:491B0F5E-501E-4F8B-89AE-184A3CA2CB3E
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Dioncomena sanje Hemp
status	sp. nov.

Treatment

Dioncomena sanje Hemp sp. nov.

Figs 1J-L View Figure 1 , 2D View Figure 2 , 3C, D View Figure 3 , 4G, H View Figure 4 , 6A View Figure 6 , 8B View Figure 8 , 9 View Figure 9 , 19 View Figure 19 , 21 View Figure 21 , 22H, I View Figure 22 , 23 View Figure 23 , 24 View Figure 24 , 25 View Figure 25 , 27 View Figure 27 , 30 View Figure 30 , 31 View Figure 31 , 32 View Figure 32 , 33 View Figure 33 , 34 View Figure 34 , 35B View Figure 35 , 36 View Figure 36

Type material.

Holotype male. Tanzania, Mangula, 7°50'38"S, 36°53'08"E, 340 m, lowland wet forest, December 2015. Paratypes: 2♂♂, 11♀♀, same data as holotype and March 2015, July 2015, September 2015, January 2016, March 2016, November 2017. Further paratypes: All Tanzania, all Udzungwa Mountains. 7♂♂, 20♀♀, Sanje Trail, lowland wet to submontane forest, August 2019, April 2020, July 2020, October 2020, January and April 2021, May and September 2022. 3♂♂, 1♀, Magombera Forest Reserve, 7°49'12"S, 36°58'42"E, 300 m, lowland forest, January 2019. Depository: CCH.

Description.

Male. General Habitus and Color Pattern. The typical Dioncomena species can be identified by its contrasting pattern of yellow, white, greenish, and black colors on its general habitus and size (Fig. 1J, K View Figure 1 ). Head and Antennae. The fastigium of the vertex in the head is compressed and narrower than scapus, sulcate above, and is typical for the genus. Thorax & legs. The pronotum has a posterior part of lateral lobes that are not or only slightly inflated. A black stripe on the pronotum is narrow and widens in metazona, parting between a yellowish triangular field (Fig. 1J, K View Figure 1 ). The fore coxa is black with a broad-based short yellow spine. The fore and mid femora have a double row of few small ventral spinules at the apical part, while the hind femur has a double row of few irregularly positioned spines at the apical part. The fore tibia has a ventral double row of irregularly set small spinules and a pair of short ventral spurs. On the dorsal inner side, a short and slender spine is present just below the tympanum, and 1-3 short black spines are along the length. The mid tibiae have a ventral double row of black spinules and three longer black, slender, and clearly hooked spines at the inner ventral apex. Tegmina & wings. Typical shape and coloration for Dioncomena . They are black with a yellowish or green field at the base (Fig. 1J, K View Figure 1 ). The stridulatory file is present on the underside of the left tegmen and is between 1.4-1.6 mm long with around 50 teeth. The teeth are broad and densely set on the inner side, getting continuously narrower towards the apical part of the file, and ending with 8-10 shorter and more widely spaced teeth (Fig. 2D View Figure 2 ). Abdomen. The tenth abdominal tergite is slightly incurved at the posterior margin with a membranous structure medially (Fig. 3C View Figure 3 ). The cerci have an apical third that is laterally flattened. The subgenital plate is longer than wide and v-shaped incurved medially (Fig. 3D View Figure 3 ).

Female. Habitus, size and color pattern are similar to the male (Fig. 1L View Figure 1 ) but lack hooked spines on the mid tibiae. Ovipositor is short and strongly upcurved (Fig. 4G View Figure 4 ). Subgenital plate has a broadly-based triangular posterior margin (Fig. 4H View Figure 4 ).

Nymphs. Freshly hatched nymphs are greenish-yellow with speckles and brown markings along the hind femora (Fig. 9A, B View Figure 9 ). Nymphs grow in size until stage three without changing their habitus (Fig. 9C View Figure 9 , about two weeks old, probably stage 2). From stage 3, wings become visible and grow larger with each stage. Depending on the environment, nymphs may become more greenish or gain more brown colors (Fig. 9D, F View Figure 9 ). From stage 5 onwards, wings are clearly visible and are slightly inflated a day or so before molting to an adult (Fig. 9E View Figure 9 ).

Measurements, (mm) males (n = 3). Body length 12.8-14.8. Length of pronotum 3.2-3.8. Length of tegmina 23.0-25.6. Length of hind femur 17.11-17.3.

Measurements, (mm) females (n = 6). Body length 14.0-16.5. Length of pronotum 3.1-3.3. Length of tegmina 25.0-27.5. Length of hind femur 18.0-20.2. Ovipositor 4.2-4.6.

Biology.

The eggs are oval and black and are deposited in the midribs or stems of leaves (Fig. 6A View Figure 6 ). Eggs laid by a female in October 2020 hatched at the end of February 2021, 4 months later, and developed into adults at the beginning of June 2021. A female collected in April 2021 laid numerous eggs in stems on April 24, which hatched on July 7, 2021. Most individuals were captured in the Udzungwa Mountains during the warm months, from December to March, but single adults were also obtained from July to September, indicating that the species is present year-round. Like the other species studied ( D. flavoviridis sp. nov. and D. ornata ), males transfer only very small spermatophores to females during mating (Fig. 8B View Figure 8 ).

Song.

See Bioacoustics.

Habitat and distribution.

The species inhabits lowland wet to submontane forests. Individuals were mostly collected as single specimens in the understory vegetation of closed forests. Its distribution is restricted to Tanzania’s Udzungwa Mountains.

Etymology.

The species is named after the Sanje Trail in the Udzungwa Mountains National Park and is a noun in apposition.

Diagnosis.

The four species of Dioncomena ( D. jagoi from the East Usambara Mountains, D. flavoviridis sp. nov. from the Nguru Mountains, D. sanje sp. nov. from the Udzungwa Mountains, and the widespread D. magombera sp. nov.) are morphologically similar, sharing a similar color pattern (Fig. 1 View Figure 1 ). However, there are several distinguishing features. The pronotal lobes in D. magombera sp. nov., D. flavoviridis sp. nov., and D. jagoi are uniformly bright yellow or yellow-green, while both sexes of D. sanje sp. nov. have a large central diffuse formed black patch on the pronotal lobes. The 10th abdominal tergite of males is very similar in the four species of the D. jagoi -group, being incurved and with a more or less conspicuous membrane between the edges (although it is very shallow in D. magombera sp. nov.). The male cerci are mostly green with black incurved tips, but in D. sanje sp. nov., the last third or so of the male cerci is laterally flattened, and in D. magombera sp. nov., the black tips of the male cerci are hooked inwardly. The pronotal lobes are laterally considerably inflated in D. flavoviridis sp. nov. and D. jagoi , but less so in D. sanje sp. nov. and D. magombera sp. nov. In D. flavoviridis sp. nov., the hind femur has a ventral black stripe reaching to about the middle or covering more than half of the outer side of the femoral area (Fig. 1D View Figure 1 ). The outer side of the hind femur is black in D. jagoi distally, then turns yellow or green and gets black again basally at the joint with the coxa (Fig. 1A, B View Figure 1 ), similar to the femoral pattern of D. magombera sp. nov. The yellow or green area on the outer side of the hind femur is often more diffuse and smaller in D. sanje sp. nov. (Fig. 1J, K View Figure 1 ). Additionally, D. ugandana sp. nov. could belong to the Dioncomena jagoi -group because of its general color pattern and the outer genitalic morphology of the male apex. The pronotum is largely deep black with a yellow stripe at the anterior margins of the lateral pronotal lobes (Fig. 10A View Figure 10 ). In D. flavoviridis sp. nov., the black median fascia on the pronotum is solid and broad, a bit narrower along the pro- and mesozona of the pronotum, then extending to cover the whole disc of the metazona (Fig. 1D, E View Figure 1 ). The central black fascia of D. jagoi is much narrower (Fig. 1B View Figure 1 ). In D. sanje sp. nov., the black fascia is also broad and solid but fuses with the black patches of the pronotal lobes on both sides (Fig. 1J, K View Figure 1 ). In D. sanje sp. nov. as well as in D. magombera sp. nov., the black fascia parts at the anterior base of the metazona into two stripes leaving a green or yellow-green triangular patch on the disc of the metazona (Fig. 1H, J View Figure 1 ). While in D. sanje sp. nov. the black median stripe of the pronotum is solid, in D. magombera sp. nov. a fine central green or yellowish line is present throughout the whole course of the black fascia (Fig. 1H View Figure 1 ). Characters distinguishing the other species and groups of Dioncomena are provided in the key. For song description see Bioacoustics section.