Biodiversity Data Journal :
Single Taxon Treatment
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Corresponding author: Analyn Anzano Cabras (ann.cabras24@umindanao.edu.ph)
Academic editor: Jennifer C. Girón Duque
Received: 04 Aug 2021 | Accepted: 19 Oct 2021 | Published: 02 Nov 2021
© 2021 Analyn Cabras, Chrestine Torrejos, Milton Norman Medina
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:
Cabras AA, Torrejos C, Medina MN (2021) Metapocyrtus dagtum sp. nov., a new flightless weevil from Davao de Oro, Mindanao Island, Philippines (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini). Biodiversity Data Journal 9: e72561. https://doi.org/10.3897/BDJ.9.e72561
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The genus Metapocyrtus Heller, 1912 is the most speciose and taxonomically complex genus in the tribe Pachyrhynchini. It is known to be endemic in the Philippines, with most species having a very narrow range of distribution. There are already more than 230 species of Metapocyrtus documented in the Philippines.
Metapocyrtus dagtum sp. nov., a new species of the genus Metapocyrtus Heller, 1912 from Davao de Oro, Mindanao Island, Philippines, is described with brief notes about its ecology. Its specific epithet is from the Cebuano word “dagtum” which means pitch black referring to the colour of the integument of the species.
beetles, biodiversity, new species, southern Mindanao, taxonomy
Davao de Oro, formerly Compostela Valley, is located in the eastern part of Davao Region, bounded by Agusan del Sur in the north, Davao Oriental in the east and the south, Davao Gulf in the southwest, and Davao del Norte in the west. It covers a total area of 4,666.93 km2, of which 3,135.96 km2 is classified as forestland. The terrain of the Province consists of flat, rolling, hilly, and mountainous portions, with its highest elevation reaching more than 2000m (i.e. Mabini, Maragusan, New Bataan and Pantukan) and the low elevation areas, at a height below 100m (i.e. Monkayo, Laak and Compostela) (
Metapocyrtus is the most speciose and taxonomically complex genus in the tribe Pachyrhynchini Schönherr, 1826 (
Prior to the field expedition, Gratuitous Permit was obtained from the Department of Environment and Natural Resources Region XI. The specimens deposited in the University of Mindanao Coleoptera Research Center were collected through sheet beating and handpicking. Vials containing 95% ethyl alcohol were used for initial storage immediately after collection. The specimens were examined under a Luxeo 4D and Nikon SMZ745T stereomicroscope for their description. The illustrations, as well as the treatment of the genitals, were identical to those described by
All measurements are in millimetres.
Codes of the collections:
Metapocyrtus Heller, 1912 =Metapocyrtus Kôno, 1942.
Type species: Apocyrtus rugicollis Chevrolat, 1881
Male
Dimensions (in mm): N=20. LB: 9.3–11.6 (holotype 9.3), LR: 1.9–2.7 (1.9), WR: 1.2–1.8 (1.2), LP: 3.0–3.9 (3.0), WP: 3.2–4.5 (3.2), LE: 7.2–7.7 (7.2), WE: 4.3–5.1 (4.3).
Habitus as shown in Fig.
Integument black. Body surface, rostrum, head and underside with weak lustre. Body subglabrous. Head subglabrous with pale-blue, lanceolate scales and adpressed white piliform scales on forehead and coloured setae on sides; forehead weakly depressed, rugose especially towards eyes, and with faint longitudinal groove not reaching vertex.
Rostrum moderately rugose, longer than wide (LR/WR: 1.58), bearing sparse and adpressed piliform scales on dorsum and long white piliform scales on lateral surface below antennal scrobe; anterolateral sides also covered with long white piliform scales; transverse basal groove distinct; longitudinal groove barely present, but replaced with weak depression; apical third of dorsum finely punctured; dorsal surface nearly flat. Eyes medium-sized and feebly convex. Antennal scape slightly longer than the funicle (scape/funicle: 2.0/1.6). Scape moderately covered with fine, white adpressed hairs and funicle with yellowish suberect hairs. Funicular antennomeres I and II nearly the same length, twice as long as wide; funicular antennomeres III–VII nearly as long as wide; club subellipsoidal, nearly three times longer than wide.
Prothorax subglobular, wider than long (LP/WP: 0.94), subglabrous, weakly punctured, weakly rugose near anterior and posterior margins, widest at mid-length, weakly convex, highest point at mid-length, lateral margins convexly rounded and posterior margin truncate. Pronotum covered with pale blue, pale yellow and bluish-green lanceolate scales and adpressed, coloured piliform scales, except along midline which is nearly bare; anterior margin with yellow-ochre and pale blue narrowly ovate scales, and lateral sides above coxae covered with yellow-ochre narrowly ovate scales.
Elytra narrowly subovate, moderately tapered towards apex (LE/WE: 1.67), slightly wider and nearly twice longer than prothorax (WE/WP: 1.34, LE/LP: 2.40), subglabrous and weakly convex; surface black, irregularly covered with pale blue, turquoise and dull yellow, round to ovate scales and coloured adpressed piliform scales; apex with very sparse, coloured, fine setae.
Legs with moderately clavate femora. Femora fairly covered with white adpressed piliform scales. Tibiae fairly covered with adpressed, white piliform scales; piliform scales longer along inner margin; weakly serrate along inner edge. Fore- and mid-tibiae bearing mucro at apex. Tarsomeres pubescent all throughout. Coxae pubescent all throughout with white piliform scales. Mesoventrite covered with white adpressed piliform scales. Metaventrite with concentration of long golden-yellow adpressed piliform scales on discs, and turquoise, light-blue and dull yellow, round scales at distal ends. Ventrite I depressed on disc, with concentration of long golden-yellow adpressed piliform scales. Ventrites II–V with concentration of golden yellow hair-like scales, but much shorter. Ventrite V flattened, apex with fine punctures and suberect white piliform scales.
Male genitalia as shown in Fig.
Female
Dimensions (in mm): N:11. LB: 9.6–11.1 (â: 10.3), LR: 2.2–2.3 (2.2), WR: 1.2–1.5 (1.3 mm), LP: 2.4–3.5 (2.8 mm), WP: 3.3–4.4 (3.7 mm), LE: 7.2–8.5 (7.6 mm), WE: 5.0–5.7 (5.2 mm).
Habitus as shown in Fig.
Females differ from males in the following: a) rostrum slightly shorter in females; b) pronotum slightly shorter than in male (LP/WP: 0.67–0.79: female, 0.94: male); c) pronotum subquadrate with widest point right after anterior margin and truncate towards posterior margin; d) pronotum rugose at middle of disc; e) absence of lanceolate and ovate scales (which are part of the variation of elytral scales of this species); f) elytra subovate (LE/WE: 1.44–1.49), wider than in male (WE/WP: 1.29–1.51, LE/LP 2.42–3.0), widest before mid-legth and less constricted towards apex, and g) elytra with minute pubescence. Other than those features, females are similar to males.
Metapocyrtus dagtum sp. nov. displays a striking variation in its elytral pattern, as well as the shape of its scale markings (Fig.
Metapocyrtus dagtum sp. nov. is readily distinguished from its congeners by the unique shape of the pronotum and body, as well as scaly markings. The new species resembles Metapocyrtus (Metapocyrtus) lindabonus Schultze, 1922 by the aedeagus and both having a glossy black body with slender and subovate elytra, and a subglobular pronotum which is truncated at the base. Metapocyrtus dagtum sp. nov. can be easily distinguished from M. (M.) lindabonus by its longer and slender rostrum, absence of two scaly spots on both sides of the disc, strongly truncate pronotum, tapered elytral apex, and the uniform presence of piliform or round scales on the elytra.
The specific epithet is from the Cebuano word “dagtum” which means pitch black, referring to the colour of the integument of the species.
The new species is known only from the type locality in Davao de Oro, Mindanao, Philippines at present. The type localities of Metapocyrtus dagtum sp. nov. are in Maragusan and New Bataan which are located in the south-eastern portion of Davao de Oro (Fig.
The new species was collected in the partially-shaded creek whose nearby ecotypes include agricultural and mixed secondary forests. The shallow creek’s vegetation includes various shrubs and ferns, such as Cyathea sp. (Cyatheaceae), Angiopteris evecta (Marattiaceae), and Diplazium esculentum (Woodsiaceae), amongst others. The new species was, however, collected on the plant Erechtites valerianifolius (Asteraceae), along the banks of the stream (Fig.
The authors express gratitude to Dr. Guillermo P. Torres Jr., Dr. Malen Arquiza and the University of Mindanao for the unwavering support towards the initiatives of the UM Coleoptera Research Center making the conduct of fieldworks to Mindanao’s unexplored forests possible, thereby paving the way for fruitful discoveries. The authors also acknowledge Mark John T. Pepito, Leslae Kay C. Mantilla and Jessa Mae B. Patalita, members of the UMCRC Team; Danny Tandang for the help in plant identification; Dr Arvids Barševskis for the continuous support, especially during our visit to Ilgas; Dr Hiraku Yoshitake during the first author’s visit to Institute for Agro-Environmental Sciences, NARO, Tsukuba, Japan; Dr Klaus-Dieter Klass and Olaf Jäger for their help during our visits to Senckenberg Natural History Collections, Dresden, Germany.