Research Article |
Corresponding author: Jenő Kontschán ( jkontschan@gmail.com ) Academic editor: Farid Faraji
© 2023 Jenő Kontschán, Sergey G. Ermilov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kontschán J, Ermilov SG (2023) Remarks on the genus Phymatodiscus Berlese, 1917, with the description of Phymatodiscidae fam. nov. and Bardizon eotvosi gen. nov., sp. nov. from Indonesia (Acari, Mesostigmata). ZooKeys 1182: 223-235. https://doi.org/10.3897/zookeys.1182.109744
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Phymatodiscidae fam. nov. is diagnosed, with Phymatodiscus as the type genus. A new genus, Bardizon gen. nov., with Bardizon eotvosi sp. nov. (from Indonesia) as the type species, is erected to accommodate the Phymatodiscus species with an eye-like dorsal depression. Six Phymatodiscus species are reclassified as Bardizon: B. aokii (Hiramatsu, 1985), comb. nov., B. haradai (Hiramatsu, 1985), comb. nov., B. oculatus (Hirschmann, 1977), comb. nov., B. kuni (Kontschán & Starý, 2011), comb. nov., B. insolitus (Kontschán & Ripka, 2016), comb. nov., and B. malayicus (Kontschán & Starý, 2012), comb. nov. The new species differs from the previously described congeners in the sculptural pattern, the shapes of the dorsal and ventral setae, and the sculptural pattern of the sternal shield of the male and the genital shield of the female. A list of all known phymatodiscid species is presented. Phymatodiscus titanicus (Berlese, 1905) is moved to the genus Bostocktrachys: B. titanicus (Berlese, 1905), comb. nov. (family Trachyuropodidae).
Soil mites, South-East Asia, taxonomy
The genus Phymatodiscus was erected by
In recent years numerous contributions have added more than 30 new species to the Uropodina mite fauna of Southeast Asia (e.g.
The specimens of the new species were cleared in lactic acid for a week and afterwards, investigated on half-covered deep slides with a Leica 1000 microscope. Drawings were made with the aid of a drawing tube on a Leica 1000 microscope. Photographs were taken with Keyence 5000 digital microscope. All specimens are stored in 75% ethanol and deposited in the Natural History Museum in Geneva. All measurements and the scale bars of the figures are given in micrometres (μm).
Setae and pores: h = hypostomal setae, st = sternal setae, ad = adanal setae, ps = post-anal seta, p = pores, lf = lyriform fissures.
Phymatodiscidae Hirschmann, 1979: 69 (nomen nudum).
Phymatodiscidae
—
Phymatodiscus Berlese, 1917.
Idiosoma oval, dorsal shield fused with marginal shield in anterior area. Central area of dorsal shield elevated from neighbouring regions and subdivided with a transversal furrow in longer apical and shorter caudal parts. Transversal furrow forms a pair of eye-like depressions in some species. Genital shield of female scutiform; genital shield of male rounded and situated between coxae IV. Prestigmatid part of peritreme hooked. Corniculi horn-like; internal malae longer than corniculi and densely pilose. Gnathosomal setae in one longitudinal row; h1 near anterior margin of gnathosoma; setae h2, h3, and h4 far from setae h1 and near each other. Setae h1 smooth and needle-like; h2 short and robust; h3 long and smooth or serrate; h4 divided into two or three short, serrate branches. Chelicerae with 1–3 teeth on both digits; internal sclerotized pore associated with levantor tendon present. Setae v1 on palp trochanter long, pilose.
All known phymatodiscid species occur in New Guinea, Indonesia, Malaysia, Vietnam, and Singapore.
Discopoma (Phymatodiscus) Berlese, 1917: 12.
Discopoma miranda Berlese, 1905: 159, by original designation.
Phymatodiscid species lacking a pair of eye-like dorsal depressions. Margins of idiosoma with or without many prolongations.
Remarks. One species, Phymatodiscus titanicus (Berlese, 1905), is transferred here from the family Phymatodiscidae to the family Trachyuropodidae Berlese, 1917. According to the dorsal characteristics (only these were illustrated by
Phymatodiscus coniferus (Canestrini, 1897)
Discopoma conifera Canestrini, 1897: 461, 470.
Phymatodiscus coniferus—
Occurrence and biology. This species has been found in New Guinea, but its habitat is unknown (
Phymatodiscus ignesemovens Hirschmann, 1977
Phymatodiscus ignesemovens Hirschmann, 1977: 64.
Occurrence and biology. This species has been found in New Guinea, but its habitat is unknown (
Phymatodiscus iriomotensis Hiramatsu, 1979
Phymatodiscus iriomotensis Hiramatsu, 1979: 108–109.
Occurrence and biology. This species was described from leaf litter in Japan (
Phymatodiscus mirabilis Hirschmann, 1977
Phymatodiscus mirabilis Hirschmann, 1977: 64–65.
Occurrence and biology. This species has been found in New Guinea, but its habitat is unknown (
Phymatodiscus mirandus (Berlese, 1905)
Discopoma miranda Berlese, 1905: 159.
Discopoma (Phymatodiscus) miranda—
Trachyuropoda miranda—Hirschmann and Zirngiebl-Nicol 1967: 21.
Phymatodiscus mirandus—
Occurrence and biology. This species has been found in Java, Indonesia, but its habitat is unknown (
Phymatodiscus polyglottis Hirschmann, 1977
Phymatodiscus polyglottis Hirschmann, 1977: 63–64.
Occurrence and biology. This species has been found in New Guinea, but its habitat is unknown (
Phymatodiscid species with one pair of eye-like dorsal depressions.
Bardizon eotvosi sp. nov.
The name was suggested by the older son of the first author and derives from small chocolates, which are similar in shape to the idiosoma of these mites.
Male.
Bardizon aokii (Hiramatsu, 1985) comb. nov.
Phymatodiscus aokii Hiramatsu, 1985: 270–273.
Occurrence and biology. This species has been described from soil from Borneo (Indonesia) (
Bardizon haradai (Hiramatsu, 1985) comb. nov.
Phymatodiscus haradai Hiramatsu, 1985: 273–275.
Occurrence and biology. This species has been described from soil from Borneo (Indonesia) (
Bardizon oculatus (Hirschmann, 1977) comb. nov.
Phymatodiscus oculatus Hirschmann, 1977: 62–63.
Occurrence and biology. This species has been found in New Guinea, where its habitat is unknown (
Bardizon kuni (Kontschán & Starý, 2011) comb. nov.
Phymatodiscus kuni Kontschán & Starý, 2011: 15–16.
Occurrence and biology. This species was collected in Vietnam, in a tropical rain forest (
Bardizon insolitus (Kontschán & Ripka, 2016) comb. nov.
Phymatodiscus insolitus Kontschán & Ripka, 2016: 292–296.
Occurrence and biology. This species was found in Singapore, where it was collected from soil (
Bardizon malayicus (Kontschán & Starý, 2012) comb. nov.
Phymatodiscus malayicus Kontschán & Starý, 2012: 184–188.
Occurrence and biology. This species was collected in Malaysia from leaf litter (
Holotype. Female. Indonesia, East Kalimantan Prov., Berau Ditrict, 1 km off the Tanjungredeb–Tnajungselor road, ca 45 km N of Tanjungredebm 2°29.5'N, 117°28.766'E, 190 m elev., primary forest, 29 September 2008, P. Schwendinger leg. Paratypes. One female and eight males, with the same collection data as the holotype.
Dorsal shield bearing smooth setae except two pairs of apically pilose setae near caudal margin. Surface of dorsal shield smooth, but web-like sculptural pattern situated anterior and posterior to eye-like dorsal depressions. Male sternal shield anterior to genital opening, and female genital shield covered by web-like sculptural pattern.
Female (n = 2). Length of idiosoma 1570–1610, width at level of coxae IV 1130–1145, colour reddish-brown. Shape of idiosoma pentagonal, its caudal margin curved.
Dorsal idiosoma
(Figs
Ventral idiosoma
(Figs
Genital shield scutiform, length 430–440, basal width 300–315, situated between coxae II and IV; surface of genital shield covered by web-like structures. Stigmata situated between coxae II and III. Presitgmatid part of peritremes with two bends; postsigmatid part very short. Pedofossae deep, their surface smooth, with separate furrow for tarsi IV. Some oval pits situated outside margin of pedofossae. Tritosternum with narrow base; its laciniae subdivided into two pilose lateral branch and one smooth central branch (Fig.
Dorsal view of Bardizon eotvosi sp. nov., holotype, female A ventral view of gnathosoma B ventral view of palp (arrow shows the palp apothele) C leg I in ventral view D leg II in ventrolateral view E leg III in ventrolateral view F leg IV in ventrolateral view G intercoxal area of male paratype.
Gnathosoma
(Fig.
Legs
(Fig.
Male (n = 8). Body 1570–1610 long and 1090–1115 wide at level of coxae.
Dorsal idiosoma. As for the female.
Ventral idiosoma
(Figs
Other characters as in female.
Developmental stages. Unknown.
The new species is dedicated to Baron Loránd Eötvös (1848–1919), scientist, physicist, the president of the Hungarian Academy of Sciences (1889–1905) and Minister of the Culture (1894–1895) on the 125th anniversary of his birth.
The new species is most similar to B. akoii (Hiramatsu, 1985), the most important differences being summarized in Table
Most important differences between the species Bardizon aokii and B. eotvosi sp. nov.
B. aokii | B. eotvosi | |
---|---|---|
Majority of dorsal setae | finely pilose | smooth |
Surface of anterior area of dorsal shield | with oval pits | smooth |
Surface dorsal shield anterior and posterior to the eye-like depressions | smooth | with web-like sculptural pattern |
Oval pits posterior to coxae IV | absent | present |
Surface of male sternal shield anterior to genital opening | smooth | with web-like sculptural pattern |
Surface of male sternal shield posterior to genital opening | smooth | with oval pits |
Apical bend of peritreme | wide and angular | hooked |
1 | Dorsal idiosoma with one pair of eye-like depression (genus Bardizon) | 2 |
– | Dorsal idiosoma without eye-like depressions (genus Phymatodiscus) | 8 |
2 | Surface of female genital shield smooth, only bearing some pits | 3 |
– | Surface of female genital shield ornamented with web-like sculptural pattern | 7 |
3 | Eye-like transversal furrows large, visible, and bordered with long setae | 4 |
– | Eye-like transversal furrows small, hidden, and not bordered with setae | B. insolitus |
4 | Dorsal setae uniform in length | 5 |
– | Dorsal setae not uniform in length | 6 |
5 | Setae on marginal shield situated in multiple rows; two pairs of long and narrow setae on caudal area of dorsal shield | B. haradai |
– | Setae on marginal shield situated in only one row; two pairs of robust setae on caudal area of dorsal shield | B. oculatus |
6 | Setae h1 marginally serrate; setae on margin of eye-like transversal furrows smooth | B. kuni |
– | Setae h1 smooth; setae on margin of eye-like transversal furrows marginally pilose | B. malayicus |
7 | Surface of anterior area of dorsal shield without oval pits | B. eotvosi |
– | Surface of anterior area of dorsal shield with oval pits | B. aokii |
8 | Margin of idiosoma with several long prolongations | 9 |
– | Margin of idiosoma without prolongation | P. polyglottis |
9 | Marginal prolongations situated only on caudal margin | P. iriomotensis |
– | Marginal prolongations situated on entire margin | 10 |
10 | Prolongations cone-like | 11 |
– | Prolongations not cone-like | 12 |
11 | Margin with more than 14 prolongations | P. mirabilis |
– | With fewer than 14 prolongations | P. coniferus |
12 | Margin with more than 14 prolongations | P. mirandus |
– | With fewer than 14 prolongations | P. ignesemovens |
We are very grateful to Dr Peter Schwendinger (MHNG) for his kind hospitality during JK’s stay in Geneva. We would like to thank Dr Jason Dunlop for his linguistic correction of the manuscript.
The authors have declared that no competing interests exist.
No ethical statement was reported.
No funding was reported.
JK and SGE wrote the manuscript, JK did the illustration.
Jenő Kontschán https://orcid.org/0000-0001-8274-4238
Sergey G. Ermilov https://orcid.org/0000-0002-0913-131X
All of the data that support the findings of this study are available in the main text.