Dioncomena ornata Brunner von Wattenwyl, 1878

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/65CA16E7-5D66-539D-990E-D146F9882006
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Dioncomena ornata Brunner von Wattenwyl, 1878
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Dioncomena ornata Brunner von Wattenwyl, 1878 View in CoL View at ENA

Figs 2F View Figure 2 , 18 View Figure 18 , 19 View Figure 19 , 21 View Figure 21 , 22J-L View Figure 22 , 23 View Figure 23 , 24 View Figure 24 , 25 View Figure 25 , 28A-C View Figure 28 , 30 View Figure 30 , 35C, D View Figure 35 , 36 View Figure 36

Dioncomena superba Karsch, 1889. Syn.

Biology.

Female Dioncomena ornata , as well as D. flavoviridis sp. nov., D. tanneri , and D. sanje sp. nov., deposit their eggs into the ribs of leaves or stems of small branches. A female collected from Kazimzumbwi Forest Reserve near the coast of Dar es Salaam deposited eggs in December 2015, with the first nymphs hatching in February 2016 and molting into adults in April 2016. Another female collected from Magoroto Forest Estate in the East Usambara Mountains laid eight eggs into the midrib of a leaf on August 31, 2019. The first L1 nymph hatched on November 3, 2019, while the last nymph emerged on December 30, 2019, almost two months later. It takes about two to four months for nymphs to develop into adults (Fig. 18 View Figure 18 ).

In the field, individuals of D. ornata were often observed in clusters on certain bushes, with males perched at the tops of branches and females gathering further down. In contrast to D. flavoviridis sp. nov. and D. sanje sp. nov., males of D. ornata transfer only small spermatophores to females during mating. However, in the three observed copulations, the process lasted 60 minutes or longer, unlike the other two species.

Phenology.

D. ornata adults were collected year-round in lowland and coastal forests, while at higher elevations in the submontane zone, such as Amani in the East Usambara Mountains or Lutindi forest in the West Usambara Mountains, only one generation per year was present, with adult individuals rarely collected between April and October. In the Uluguru Mountains, where D. ornata was screened from 2016, the species was only encountered once in March 2020 at elevations between 1700 and 2100 m, indicating that its development is likely triggered by temperature and that only one generation is produced in the montane zone. In Zanzibar, D. ornata probably develops only one main generation per year, with adults found from December to April, with highest abundance in February, while only a few individuals were found in October 2018, and the species was not observed during other checks in October (2016, 2017). Eggs from D. ornata laid in the laboratory in February 2022 hatched at the end of May 2022, with the first adults molting at the beginning of August 2022. However, laboratory conditions make it difficult to exclude the possibility that high temperatures and constant moisture may have triggered earlier hatching.

Habitat and distribution.

D. ornata is a species of clearings and forest paths, distributed from coastal to montane forests in Kenya and Tanzania.

Notes on D. ornata from Zanzibar and mainland Africa.

In 1878, Brunner v. Wattenwyl established the genus Dioncomena based on specimens of D. ornata collected on Zanzibar. Later, Karsch (1889) described D. superba from the East Usambara Mountains, noting that the new species differed from Zanzibar specimens only in its color pattern. Ragge (1980) compared a large series of specimens from mainland Africa and Zanzibar and concluded that the differences between the two populations were only in color pattern, while other features such as stridulatory files, the 10th abdominal tergites in males, and general measurements were similar. Therefore, he synonymized D. superba with D. ornata .

However, since Ragge only examined dried specimens and did not see alive specimens from Zanzibar and various mainland areas, he may not have been aware of the significant differences in color pattern. Zanzibar populations are distinctly red and black, while mainland specimens never show any red in their color pattern but often have vivid turquoise stripes (see Fig. 35C, D View Figure 35 ). Generally, the color pattern in Dioncomena species, including the widespread D. ornata from various mountain ranges and along the coast, is highly stable, suggesting that subspecies status should be considered for mainland populations of D. ornata . Further studies on genetics and chromosomes are needed to clarify the status of the Zanzibar and mainland populations.