Ranatra stali Montandon, 1905
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publication ID |
https://doi.org/ 10.26107/RBZ-2021-0005 |
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publication LSID |
lsid:zoobank.org:pub:D63943BE-00B0-409E-BCE4-96942D33114E |
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DOI |
https://doi.org/10.5281/zenodo.5449953 |
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persistent identifier |
https://treatment.plazi.org/id/610CF11B-E00B-FFD0-FC32-23FAFC01F996 |
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treatment provided by |
Diego |
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scientific name |
Ranatra stali Montandon, 1905 |
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Ranatra stali Montandon, 1905 View in CoL
( Figs. 1A View Fig , 2 View Fig )
Ranatra parmata Stål, 1870: 707 View in CoL (misidentification).
Ranatra stali Montandon, 1905: 390–391 View in CoL (type locality: Mindanao, Philippines). — Lansbury, 1972: 296–298 (redescription).
Type material examined. Lectotype (female, NRMS, designated by Lansbury, 1972): “Mindanao.”, “collectio\ Haglund ”, “Type.”, “ Typus ” [red label], “ Ranatra \ Ståli Montandon \ Type 1903.” [handwritten, last line in red ink], “480\ 62” [red label, last line handwritten], “51\ 67” [red label, last line handwritten], “ Naturhistoriska \ Rijksmuseet \ Stockholm \ Loan no 251/01”, “14”.
Additional material examined. PHILIPPINES ( NHMW, UPLB, USC, ZCW, ZRC): Mindanao : 4 males, Bukidnon Province, Malaybalay, Kaamulan Site, 650 m a.s.l. ; 2 females, Agusan del Sur Province, San Francisco, Bayogan, Tagkunayai creek , 8°27′24″N, 125°58′12″E, 54 m a.s.l. GoogleMaps Samar: 4 males, 2 females, Northern Samar Province, Veriato, El Amigo, Veriato Falls ; 1 male, Northern Samar Province, San Joaquin, stream near sea ; 1 female, Western Samar Province, E Basey, Sohoton NP, creek ; 2 males, Western Samar, Basey .
Description of lectotype. Colour uniformly light brown, probably faded by light.
Measurements. Body length 39.6; respiratory siphon> 9.0 (apex broken); width of head 3.27; width of eye 1.05; interocular width 1.17; rostral segment 3: 0.72, segment 4: 0.52; anterior width of pronotum 2.75; posterior width of pronotum 3.40; length of pronotum 9.90; length of anterior lobe of pronotum 7.6; length of posterior lobe 3.5. Length of distal part of fore femur 4.0; proximal part of fore femur 6.1. Maximum width of fore femur at basal part 0.94, at median tooth 0.92. Lengths of leg segments: fore leg: coxa 6.7, femur 10.1, tibia 3.9, tarsus 0.8; middle leg: femur 16.8, tibia 15.6, tarsus broken off; hind leg: femur 16.7, tibia 19.6, tarsus 2.4.
Structural characteristics. Clypeus as high as lorum, clypeoloral sulcus shallow; vertex with prominent, high tubercle. Eye slightly narrower than interocular space. Anterior collar of pronotum raised to paired tubercles. Anterior lobe of pronotum 2.2× as long as posterior lobe, sublateral swellings caudally on pronotum distinct. Mesoscutellum 1.9× as long as broad, dorsal surface smooth, with paired grooves on caudal half. Prosternum with paired broad, shallow longitudinal depressions separated by low and blunt median carina; median carina rather indistinct on posterior half. Mesosternum invisible in lectotype. Metasternum anteromedially depressed, posterior twothirds with low median carina, posterior margin angularly emarginated, with sublateral grooves. Smallest distance between hind coxae ca. 0.8× distance between middle coxae. Hemelytra posteriorly reaching to anterior third of abdominal tergum VI. Hind femur not reaching operculum. Operculum projecting beyond apex of abdomen.
Measurement of additional specimens. Males: body length 35–38; length of siphon 12.9–15.9; width of head 3.00–3.41; interocular width 1.04–1.27; width of eye 0.97–1.07; pronotal length 9.12, anterior pronotal length 7.3; posterior pronotal length 3.0; anterior width of pronotum 2.49; posterior width of pronotum 2.91. Females: body length 39–43; length of siphon 14.1–15.2.
Diagnosis. Body length: males 35–38, females 39–43; ratio of siphon length: body length ca. 0.35–0.42; lorum higher than clypeus and with a nodule dorsally; ratio of eye width: interocular width ca. 0.84–1.00; pronotal length ca. 1.34–1.52× fore coxa length; hemelytra reaching about anterior third of abdominal tergum VI; posterior margin of metasternum angularly emarginated, with sublateral grooves ( Fig. 2F View Fig ); flexor side of fore femur with a tooth and a carina at ca. 0.4 distal part, pre-apical part with a pair of small teeth on either side of flexor side ( Fig. 2D, E View Fig ); hind femur, when folded back parallel to body at most reaching posterior margin of abdominal sternum VI (in males) or just surpassing midlength of sternum VI (in females). Male paramere: thickest at basal third, constricted at ca. distal third, distal third bent downwards; ventral margin gradually tapering from middle part towards the constricted part, then followed by a small, obtuse, trapezoidal process bearing tuft of setae; from inner view, pre-apical process appearing sub-rectangular due to a small round projection shorter than tuft of setae; apical hook thick, curved with rounded tip; gap between hook and pre-apical hook narrow ( Fig. 2H, I View Fig ).
Remarks. Montandon (1905) noted that the “ Ranatra parmata ” from the Philippines reported by Stål (1870) was actually a new species and described it as Ranatra stali . He also included two specimens from Borneo and from Moluccas as Ranatra stali , but subsequently, he separated those as another taxon, Ranatra spinifrons (see Montandon, 1910b, 1914, also see Tran & Poggi, 2019 for further discussion).
The identity of Ranatra stali was fixed by Lansbury (1972), who designated a female syntype from Mindanao as the lectotype and described it (the interpretation of R. stali is based on this specimen; see description above and Figs. 1A View Fig , 2 View Fig ). Lansbury (1972) also included and treated specimens from Zamboanga (western Mindanao), Leyte, and northern Luzon (Mountain Province) as conspecific to R stali . Subsequently, J. Polhemus & Reisen (1976) also reported R. stali from Luzon, but based on only nymphs. After comparative study of numerous specimens from various major islands of the Philippines, we recognise five distinct and related species. One is Ranatra stali , with its distribution restricted to the biogeographic subregion of Greater Mindanao (records from Mindanao and Samar). The other four are new to science. Based on extensive samples from major islands of the Philippines, we conclude that the specimens from Luzon studied by Lansbury (1972) and Polhemus & Reisen (1976) were not R. stali , but a new species.
Lansbury (1972) noted that R. stali was rarely represented in collections. The main reason seems to be that in earlier times more attention was paid to collecting in stagnant water bodies than in streams. However, all species of the R. stali complex live at the edges of lentic sections of running waters. Rarely, specimens are also found in pools of intermittent streams, too. Shaded habitats are generally preferred. Often specimens sit hidden at undercuts of banks or between the roots of trees hanging into the water (Zettel, pers. obs.).
For further comparative notes, see Remarks under R. pangantihoni , new species.
Distribution. Philippines: Greater Mindanao Region: Mindanao and Samar. Lansbury’s (1972) record from Leyte needs verification.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
