Philippine Journal of Science 149 (3): 571-579, September 2020 ISSN 0031 - 7683 Date Received: 15 Apr 2020 Morphology and Morphometrics of Diotarus verrucifer (Stål, 1877), a Pygmy Grasshopper Endemic to Mindanao Alma B. Mohagan1,2, Romeo R. Patano Jr.1,2*, Emmanuel P. Leaño1,2, Merced G. Melencion1,2, Fulgent P. Coritico1,2, and Victor B. Amoroso1,2 1Center for Biodiversity Research and Extension in Mindanao 2Department of Biology, College of Arts and Sciences Central Mindanao University, Musuan, Maramag, Bukidnon 8710 Philippines Diotarus Stål, 1887 (Tetrigidae: Cladonotinae) is a genus of pygmy grasshoppers with four species, all of which are inhabiting the Philippines with one species known also from Sulawesi. Diotarus verrucifer Stål, 1877 was originally described from Semper’s collection and from an unknown location from the Philippines. The species has been reported once since the description by Gůnther in 1938. In this study, we report species diagnostic characteristics and describe its natural habitat. The brief morphological description and, more importantly, the updated distribution map are firsts for this species. The species is similar to Diotarus galeatus and is still not clear if they represent separate species. We present detailed measurements of our specimens in order to make comparison in the future possible. Keywords: Diotarus verrucifer, groundhopper, Marilog District, measurements, Mt. Agad-agad, pronotum, tectiform INTRODUCTION the head (Tumbrinck 2014). Those species have crested, tectiform pronotum with truncated apex, giving the The genus Diotarus Stål, 1877 belongs to the family animal a leaf-like pattern. This is only one of the genera Tetrigidae and subfamily Cladonotinae. Members of this with leaf-like mimicry (Skejo et al. 2019). The holotype family are characterized mainly by having filiform or originated from the Semper’s collection, and most of thicker antennae, and the medial ocellus is situated below the grasshoppers’ material lack detailed locality data the lower margin of the eyes. The dorsal margin of the (Stål 1877; Bolívar 1887; Tumbrinck and Skejo 2017; anterior and middle femora has a well-developed carina, Muhammad et al. 2018). with the facial carina of the frontal costa considerably widened in which they enclose a widened scutellum Based on Semper’s collections as shown by Tumbrinck (wider than the scapus) (Tumbrinck 2014). However, (2014), except for D. verrucifer, some specimens of the subfamily seems not to be monophyletic (Tumbrinck species from the genus Diotarus were collected in Luzon – 2014; Skejo et al. 2019). The genus includes four species, specifically from Norzagaray, Bulacan and Mount Bulusan three of which are endemic in the country while Diotarus in Sorsogon (D. galeatus) – while other species were pupus is also known from Sulawesi. The genus Diotarus collected in Camarines Sur (D. pupus) and Los Baños, is unique through its pronotum by having semicircular to Laguna (D. ikonnikovi). truncated apex and elevated anterior margin in relation to New distribution records and habitat of D. verrucifer are *Corresponding Author: [email protected] described in this paper. We aim to provide its morphological 571 Philippine Journal of Science Mohagan et al.: Morphology and Morphometrics of Vol. 149 No. 3, September 2020 Diotarus verrucifer description, as we have observed a lack of actual images in – number of outer spine on hind tibia; 1stTL – first tarsal its natural environment online or in literature. The specific segment (basal) length; 3rdTL – third tarsal segment localities on which this species can be found were also (apical) length (without claws); SGPL – subgenital illustrated. We provide habitat description with supporting plate length; SGPW – subgenital plate width; OVDL – images. This study provides new pygmy grasshoppers ovipositor dorsal valve length; OVDW – ovipositor dorsal records from the area in which we recently recorded valve width (maximum, including denticle); OVVL – Spartolus pugionatus (Mohagan et al. 2020). ovipositor ventral valve length; and OVVW – ovipositor ventral valve width (maximum, including denticle). All measurements are shown in millimeters. All of the MATERIALS AND METHODS collected specimens examined in the study were mounted and then deposited to the Central Mindanao University, University Museum, Zoological Section, Tetrigidae Entry Protocol and Permits Collection. Necessary permits such as an approved gratuitous permit (GP) from the Department of Environment and Natural Studied area. The study was conducted in Mt. Agad-agad, Resources, in compliance with the Philippine Republic Sitio Langinlanon, Barangay Pugaan, Iligan City, Lanao Act No. 9147 for the collection of the specimens, and del Norte and Marilog District, Davao City Philippines – the Institutional Animal Care and Use Committee permit as shown in Figure 1 and are listed in Table 1. Other than for animal handling were obtained prior to the conduct these localities, there are no other georeferenced localities of the research project. for this species. We give approximate coordinates for Davao and Zamboanga, the localities for which Günther reported this species. Table 1 shows all the known Photography and Measurements (published) localities together with their accompanying Documentation of the specimens was conducted using a references, as well as new localities present in this study. Canon™ digital single-lens reflex camera with the use of a stereomicroscope. Small body parts such as the antennae were measured using an ocular micrometer. The studies of Skejo and Berner (2017), Tan and Artchawakom (2015), RESULTS AND DISCUSSION Tumbrinck and Skejo (2017), and Muhammad et al. (2018) were used as guides for the measurements. The following measurements were taken: Family Tetrigidae Rambur, 1838 Subfamily Cladonotinae Bolívar, 1887 BL – body length (length from vertex of head to apical Genus Diotarus Stål, 1877 margin of subgenital plate); PL – pronotum length (from the anterior margin (FM included if present) to the tip); Species included: Diotarus galeatus Bolívar, 1887, PW – pronotum lobe width (in its widest part); PH – endemic to Luzon (Angat and Norzagaray); Diotarus pronotum height (from the lowest part of the lateral lobes ikonnikovi Bey-Bienko, 1935, also endemic to Luzon to the highest part of dorsum); FFL – fore femur length; (Los Baños); Diotarus pupus Bolívar, 1887, known from FFW – fore femur width (in the middle); MFL – mid the Philippines and with records from Sulawesi that need femur length; MFW – mid femur width (in the middle); to be checked. HFL – hind femur length (from the base to the tip of the Species verrucifer Stål, 1877 by original monotypy. knee); HFW – hind femur width (in its widest parts); VW – vertex width; EW – compound eye width (in Type locality: Philippines, no specified type locality in frontal view between the eyes, or in dorsal view between Semper’s collection. the place of the supraocular lobes); SW – scutellum (or Distribution: Philippines. Mindanao: Lanao del Norte: frontal ridge) width (between the facial carinae); and IAH Iligan City (new locality record); Davao Region: Marilog – infrascapular area height (in its highest part). District (new locality record) The following measurements were also made: Material examined in this study. Philippines, Mindanao MAL – middle segment of antenna length (7th or 8th Island, Lanao del Norte, Iligan City, 08°27’31.30”N, segment); MAW – middle segment of antenna width (7th 125°35’43.20”E; 325 masl, 24-ii-2020, 1 male and 2 or 8th segment); 1stAW – first antennal segment width females, coll. A.B. Mohagan, R.R. Patano, F.P. Coritico, (in the middle of the segment) or the scapus width; HTL and V.B. Amoroso [repository (CMU-UM)]; 1 male and – hind tibia length (from knee to base of apical spine); 5 females, same locality: Davao del Sur: Davao City, n(HTIS) – number of inner spine on hind tibia; n(HTOS) Marilog District, Marilog Forest Reserve, 07°27’13.74”N, 572 Philippine Journal of Science Mohagan et al.: Morphology and Morphometrics of Vol. 149 No. 3, September 2020 Diotarus verrucifer Figure 1. Map of the Philippines (A) and Mindanao (B) showing the distribution of Diotarus verrucifer Stal, 1877. The study was conducted from months of February 2018 to February 2020. Localities are shown in Figure 1 and in Table 1. Table 1. Localities in from which Diotarus verrucifer is known, together with information on coordinates, elevation, date of research, and reference for each. Locality Coordinates Elevation Date Reference Unknown region, Philippines Unknown Unknown 1887 Stål 1877 Mindanao: Davao* 07°11’26.55”N, Unknown 1938 Günther 1938 125°27’19.23”E Mindanao: Zamboanga* 06°55’17.19”N, Unknown 1938 Günther 1938 122°04’44.45”E Mt. Agad-agad, Sitio Langinlanon, Barangay 08°27’31.30”N, 216–420 masl February 2020 Present study Pugaan, Iligan City, Lanao del Norte 125°35’43.20”E Lawi-lawi Forest Reserve, Sitio Maharlika and 07°27’13.74”N, 1220–1240 masl February 2018 – July Present study Sitio Calinan, Barangay Baganihan 125°15’1.12”E 2019 Mt. Malambo, Barangay Datu Salumay 07°29’87”N, 1,151–1,178 February 2018 – July Present study 125°15’22.23”E masl 2019 Lola Mommy’s Rainforest, Sitio Epol, Barangay 07°27’19.73”N, 1,197–1,345 February 2018 – July Present study Baganihan 125°14’33.37”E masl 2019 Mt. Ulahingan, Sitio Tagumpay, Barangay Datu 07°28’29.89”N, 1,280–1,320 February 2018 – July Present study Salumay 125°16’36.77”E masl 2019 *Günther’s records were identified with uncertainty, but they likely belong to D. verrucifer, as D. galeatus seems to endemic to Luzon Island. 573 Philippine Journal of Science Mohagan et al.: Morphology and Morphometrics of Vol. 149 No. 3, September 2020 Diotarus verrucifer 125°15’1.12”E, 1,171 masl, 18-ii-2020, coll. A.B. morphology is very similar, if not the same between the Mohagan, R.R. Patano Jr., E.P. Leaňo, M.G. Melencion, two. D. verrucifer has a somewhat stouter pronotum, and and V.B. Amoroso [repository (CMU-UM)].