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
Author
Hemp, Claudia
https://orcid.org/0000-0001-9170-7113
University of Bayreuth, Department Plant Systematics & Senckenberg Biodiversity and Climate Research Center, Frankfurt, Germany
claudiahemp@yahoo.com
Author
Montealegre-Z, Fernando
https://orcid.org/0000-0001-5186-2186
University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Lincoln, UK
Author
Woodrow, Charlie
University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Lincoln, UK
Author
Heller, Klaus-Gerhard
https://orcid.org/0000-0002-3331-3228
Triesdorf Bahnhof 8, 91732 Merkendorf, Germany
text
Deutsche Entomologische Zeitschrift
2023
2023-07-10
70
2
221
259
http://dx.doi.org/10.3897/dez.70.100804
journal article
http://dx.doi.org/10.3897/dez.70.100804
1860-1324-2-221
2824CBF6C72A4397B944262D324AF5D6
7EB2FB6659E4538C811B62C9D8009E3D
Dioncomena versicolor Hemp
sp. nov.
Figs 2I
, 13A-C
, 15A, B, D, E
, 19
, 21
, 22O
, 26I, J
, 30
, 36
Type material.
Holotype
male. Tanzania, Uluguru Mountains, montane forest above Morningside,
6°53'46"S
,
37°40'14"E
, 1600 m, February 2016.
Paratypes
.
2♂♂, 2♀♀, same locality as holotype and February 2017 and March 2020. Depository: CCH.
Description.
Male.
General habitus and color pattern. Small for
Dioncomena
but with a typical habitus for the genus and a striking color pattern. Head and pronotum blue with black lines or stipes. The pronotum has a green median part bordered by red-brown fasciae, with a longitudinal black stripe in the midline of the pronotal lobes, and the remaining part of the lateral lobes is blue. The abdomen has a yellow broad fascia on the lateral sides, bordered by black fascia, and a median black fascia on the tergites, with a blue venter. The legs are predominantly black, with the hind
femora's
basal parts in red-brown (Fig.
15A
). Head & antennae. The fastigium of the vertex is compressed, narrower than the scapus, and sulcate above, typical for the genus. Thorax & legs. The posterior part of the lateral lobes is not markedly inflated. The fore coxa lacks a spine, only a blunt knob is present. The fore, mid, and hind femora have only a few very tiny spinules ventrally in the apical area. The fore tibia has a ventral double row of irregularly set small spinules and a pair of short ventral spurs. The mid tibiae have a ventral double row of black spinules, with the apical
part's
spinules only slightly hooked. Tegmina & wings. The tegmina and wings are black with an elongated blue field at the base (Fig.
15A
). The stridulatory file on the underside of the left tegmen is about 1 mm or less long, with around 54-55 teeth. The teeth are densely set along the length, with the apically teeth getting smaller and more widely set. The file is slightly downcurved in its apical part (Fig.
2I
). Abdomen. The tenth abdominal tergite is black and incurved at the posterior margin (Fig.
13A, B
). The cerci are laterally flattened, especially at the apex, green with a black tip (Fig.
13A-C
). The subgenital plate is longer than wide, u-shaped incurved medially (Fig.
13C
).
Figure 15.
Habitus of male (
A
) and female (
B
)
D. versicolor
sp. nov. and male (
C
) and female (
D
)
D. tanneri
. Morphological details of female
D. versicolor
sp. nov., subgenital plate (
E
) and ovipositor (
F
). Scale bars: 1 mm.
Female.
The female has a similar habitus to the male but lacks the
male's
colorful pattern, with mostly brown-red and green colors. The head, pronotum, tegmina, and body lack the blue parts present in males, and the tegmina are brown rather than black (Fig.
15B
). The ovipositor is small and upcurved (Fig.
15F
), and the subgenital plate is small, triangular, with an evenly curved posterior margin (Fig.
15E
).
Measurements, (mm) males (n = 3). Body length 10.4-11.5. Length of pronotum 3.1-3.3. Length of tegmina 18.5-19. Length of hind femur 15.5-16.0.
Measurements, (mm) females (n = 2). Body length 11.5-13.5. Length of pronotum 2.8-3.0. Length of tegmina 17.7-18.0. Length of hind femur 16.1-16.2. Ovipositor 4.5-4.6.
Phenology.
Similar to
D. ngurumontana
sp. nov. and
D. tanneri
, this species likely has only one generation per year, which is an adaptation to the cooler temperatures found in montane elevations. Adult specimens were only collected twice, in February 2016 and March 2020. During all other months when the forest was visited (March, April, June, August, November 2016, February, November 2017, April 2019, October 2020), no adult specimens were observed.
Habitat and distribution.
This species can be found in montane forests (1800-2100 m) along open paths and clearings in the Uluguru Mountains of Tanzania.
Song.
See Bioacoustics.
Etymology.
Named for its distinct and colorful pattern, as reflected in its Latin name,
Dioncomena versicolor
, which means variegated or colorful.
Diagnosis.
D. versicolor
sp. nov. and
D. ngurumontana
sp. nov. are similar in morphology, but can be differentiated by the number of teeth on the male stridulatory files (over 50 in
D. versicolor
sp. nov. and 32 in
D. ngurumontana
sp. nov.) and overall color pattern, which is a stable character in
Dioncomena
. Both species are the sister group to
D. tanneri
, endemic to the Usambara Mountains (Fig.
15C, D
).
D. tanneri
has a compact stridulatory file with about 35 teeth, similar to
D. ngurumontana
sp. nov. All three lack a median dark stripe on the pronotum, but have a blue (males of
D. versicolor
sp. nov. and both sexes of
D. ngurumontana
sp. nov.) or green (females of
D. versicolor
sp. nov. and both sexes of
D. tanneri
) colored medial area bordered by brownish fasciae mottled or bordered with white or black areas, while the rest of the pronotum is green, blue, yellow, or hazel (see Figs
12
,
15
). The tenth abdominal tergite and male cerci are similar in all three species (Fig.
13
). See key for differentiation from other species. For song descriptions see Bioacoustics section.