Philippine Journal of Science 150 (4): 809-816, August 2021 ISSN 0031 - 7683 Date Received: 19 Jan 2021

Distribution of the Mindanao Spiky-helmed Pygmy Grasshopper Misythus echinatus (Stål, 1877) (: Cladonotini)

Romeo R. Patano Jr.1,2*, Alma B. Mohagan1,2, 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

Misythus Stål, 1877 (Tetrigidae: Cladonotinae) is a diverse genus of pygmy grasshoppers with 27 species and two subspecies, all of which are endemic to the islands of the Philippines. Here, the emphasis is put on the spiky wingless pygmy grasshopper, Misythus echinatus (Stål, 1877). The species is endemic to northern Mindanao and adjacent islands (Siargao Island, Bucas Island, Surigao, Iligan, and Butuan). The last published records originate from 1916 and most of the specimens hitherto reported lacked habitat descriptions and especially images of the species in its natural environment. In this study, we report the species for the first time from Bukidnon and Davao regions; we update its distribution in Mindanao and describe its natural habitat with supporting images. An updated distribution map for this species is provided, together with detailed measurements of male and female specimens, in order to make a comparison between different populations possible.

Keywords: endemic species, measurements, montane forest, Mt. Malimumu, pronotum, ultramafic substrate

INTRODUCTION by having high and warty pronotal projections and are wingless (Tumbrinck 2014). The Philippine endemic genus Misythus Stål, 1877 belongs to the family Tetrigidae, subfamily Cladonotinae The genus Misythus includes 27 species and two subspecies (Cigliano et al. 2021), tribe Cladonotini (Bhaskar et al. – all found in the Philippines. This genus is unique 2020; Tumbrinck et al. 2020). Formerly known from concerning the diversity of pronotum (Hebard 1923). genus Cladonotus Serville, 1838 endemic to Sri Lanka Misythus echinatus is a Mindanao-endemic species but (Stål 1877; Castro de Elera 1895). Members of this for its very holotype, no specified locality is known. The subfamily are characterized mainly by having widened specimen originated from the Semper’s collection (Stål scutellum (Tumbrinck 2014). There are more than 1,950 1877). Specimens with exact localities were first thoroughly known species within the family, and new species are studied by Hebard (1923) based on collections of W.F. discovered every year in Mindanao – for example, from Boettcher and C.F. Baker. Based on these collections, all the genus Cladonotella (Tan et al. 2019), Arulenus (Skejo specimens of the species were collected in Mindanao – and Caballero 2016), and Tegotettix (Patano et al. 2021). specifically from Siargao Island (1916), Bucas Island, Species under the genus Misythus are characterized Surigao, Butuan, and Iligan lacking exact coordinates, habitat descriptions, and supporting images. For a century, *Corresponding Author: [email protected] no more records were reported on the species.

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Thus, this short study updates the distribution and and random sampling methods was implemented in the describes the habitat of M. echinatus. This study study. The collection of specimens was conducted along an provides a new record of the species in the region where established 2-km transect in each site covering 10 m x 5 m Spartolus pugionatus, Diotarus verrucifer, and Arulenus on both sides. A study site is described accordingly through validispinus were recently recorded from the neighboring percentage estimations, in which dominant plant species in locality and mountain ranges (Mohagan et al. 2020a, b, c). the area were identified (VBA: one of the authors) using Co’s Digital Flora website (Pelser et al. 2011 onwards). Male and female specimens of Misythus echinatus were MATERIALS AND METHODS collected through handpicking whenever encountered during the diurnal (07:00–15:00h) and nocturnal (17:00– 22:00h) periods. They were then put in vials filled with Entry Protocol and Permits 95% ethyl alcohol for preservation. Specimens were air- Obligatory permits such as an approved gratuitous permit dried and mounted. Images of the species were taken using (GP) were obtained from the Department of Environment a DSLR Canon camera combined with a stereomicroscope. and Natural Resources in compliance with Republic Final images of the species were edited using licensed Act No. 9147 for the collection of the specimens and Adobe Photoshop CS software. The ocular micrometer Institutional Care and Use Committee (IACUC) and digital caliper were used to measure the specimens. permit for animal handling. The standard methodologies of Skejo and Bertner (2017), Tumbrinck and Skejo (2017), Skejo (2017), and finally Field Sampling, Collection of Specimens, Muhammad et al. (2018) in gathering measurements and Photography, and Measurements describing pronotal projections were employed. A male The study was conducted in the lower and upper specimen of the species from the Species File montane forest of Mount Malimumu, Sitio Nabangkal, was also measured for comparison. Barangay Magkalungay, San Fernando; Mt. Ulahingan, The following measurements were taken: body length Sitio Tagumpay, Barangay Datu Salumay; and Mount (BL) (from the anterior end of the pronotum to the Kitanglad Range, Kaatuan, Lantapan, Bukidnon (Figure posterior end of the subgenital plate), pronotum length 1). A combination of standard belt-transect, opportunistic,

Figure 1. Map of the Philippines (A) and Mindanao (B) showing the updated distribution of Misythus echinatus (Stål, 1877). Localities are also shown in Table 1.

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(PL), pronotum lobe width (PLW), pronotum height (PH), known not to include detailed labels (“Philippines” only). fore femur length (FFL), fore femur width (FFW), mid Thus, more species from the collection need to be studied femur length (MFL), mid femur width (MFW), hind femur in order to find out which region did Semper collected in length (HFL), hind femur width (HFW), vertex width (retrieved from the Orthoptera Species File). (VW), compound eye width (CEW), abdominal length (AL), and antennal length (AnL). The specimens collected Diagnosis of the species. The species can be easily and examined in this study are deposited in Central distinguished by its bulky appearance with irregular Mindanao University, University Museum, Zoological positions of heavy and stout spines scattered throughout Section, Tetrigidae Collection. All measurements are its pronotum (Figure 2), head (Figures 3A–D), and legs, shown in millimeters. especially femora (Figures 3E–G). Other species of the genus have different pronotal projections [compare with Hebard (1923)] – usually with long frontal part or compresso-elevated dorsum. RESULTS AND DISCUSSION Family Tetrigidae Rambur, 1838 Subfamily Cladonotinae Bolívar, 1887 Tribe Cladonotini Bolívar, 1887 Misythus echinatus (Stål, 1877) This species is originally known from the genus Cladonotus Sausurre, 1862 endemic to Sri Lanka (Stål 1877; Castro de Elera 1895). It was then moved to the genus Misythus Stål, 1877, which is a quite large genus with 27 species and two subspecies all known in the Philippines (Hebard 1923). Members of the genus are non-flyers and can be easily distinguished by having frontomedial projection considerably produced forward Figure 2. Misythus echinatus (Stål, 1877). Dorsal view and lateral and presence heavy and stout spines through their legs, view of male (A and B) and female (C and D). Scale pronotum, and head (Hebard 1923). bar: 10 mm. Misythus echinatus (Stål, 1877) is one of those spinose species. The species is recorded in the Philippines and some records might be in Luzon but still needs validation as more likely it was misidentified (Bruner 1915; Günther 1938; Blackith 1992). As being recorded almost a century ago, there is no known ecological and updated distribution of the species. Material examined. Philippines • (2/2) 1♂1♀ 1 and 2 – Bukidnon, San Fernando, Barangay Magkalungay, Sitio Nabangkal, Mount Malimumu, 7°52’50.58” N, 125°24’32.64” E, 1,074 masl, 22 Aug 2020, AM-011; (1/1) 1♂ 3 – Mt. Ulahingan, Sitio Tagumpay, Barangay Datu Salumay, 07°28’29.89”N, 125°16’36.77”E, 1,300 masl, February 2019, AM-010; (1/1) 1♀ 4 – Mount Kitanglad Range, Kaatuan, Lantapan, Bukidnon, 08°06’29.54”N, 124°56’0.61”E, 1,600 masl, September 2018, A.B. Mohagan, R.R. Patano Jr., and V.B. Amoroso, Central Mindanao University, University Museum, Zoological Section; (1/1) 1♂ (holotype) 5 – the Philippines with no Figure 3. Misythus echinatus (Stål, 1877): A) face in frontal view; specific locality (Semper’s collection). B) head in dorsal view; C) mouthparts in ventro-frontal view; D) head and anterior part of pronotum in lateral On the type locality. The Philippines is simply noted, as view; E) fore, F) middle, and G) hind femora in lateral there is no specified locality for the holotype label. The views; H) abdominal apex and subgenital plate in ventral holotype originated from Semper’s collection retrieved view; I) antennae; J) posterior tibia and tarsus in lateral at Orthoptera Species File website, and the collection is view. Scale bars: 1 mm.

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Brief morphological description. The body has an overall The median carina of the pronotum is elevated between the black color. The frontomedial projection (frontal process) shoulders and the lamellate; in dorsal view, it is strongly is laterally compressed. The frontomedial projection is undulate having the lateral outline of convex except before considerably produced forward and above far beyond the its narrow projection above the head. head; in lateral view, it is irregularly formed. Frontal costa, pronotum, and femora are supplied with many stout spines In comparison with Hebard (1923) specimens and the holotype, the present study collected and examined The abdomen is also colored black with a cone-like specimens with longer pronotum (longer for more than > subgenital plate (in females). The width of each of the 1.75 mm than hitherto reported) (Table 2). eight abdominal segments is about 0.8–0.9 mm (Figure 3H). Four lateral spines on the lateral margins of the external lateral carina near the apex are also much longer compared It has 16 segments of filiform antennae (Figure 3I). The with Hebard (1923) and the holotype. The colors of the hind tibiae are thinner compared to the femora bearing specimens collected in the study vary from brown to black, five stout spines in the distal parts (Figure 3J). while the holotype is clearly black. Living specimens have their more visible colors compared to those of museum The dorsal surface of the species’ pronotum is heavily collections. spinose (Figure 4), with 2nd and 3rd frontolateral spines that are almost the same in length (0.9 mm) (Figure Distribution. The species inhabits tropical upper 4A); the ventrolateral projection is composed of three mountainous rainforests of the island of Mindanao and spines, of which the middle is the longest (0.95 mm neighboring islands (the Philippines) at 1,074–1,600 long) (Figure 4B); others include two promedial and two masl: known from Dapa, Siargao Island, Bucas Islands, promediolateral spines (Figure 4C), metalateral spines (1.5 Surigao, Agusan, and Misamis by W. Boettcher and C.F. mm long) (Figure 4D), two metamediolateral spines (1.2 Baker (Hebard 1923); and Davao (Mount Ulahingan) mm long) (Figure 4E), four metamedial spines (Figure and Bukidnon Region (Mount Malimumu and Mount 4F), four small spines on lateral margins (Figure 4G), and Kitanglad) (present study) (Table 1). the caudal apex of the pronotum produced into two spines forming a V-shape (0.9–1.0 mm) (Figure 4H). Vernacular name proposal. There are no known local names reported on this species according to the local people of Marilog District in Davao City, Mt. Kitanglad in Lantapan (Bukidnon), and Mt. Malimumu in San Fernando (Bukidnon). With that, we propose the English name Mindanao spiky-helmed pygmy grasshopper. Spiky- helmed refers to the overall structure of the species that is covered with spines, helmed refers to the anterior structure of its pronotum, while Mindanao refers to the island the species is inhabiting. Habitat, ecology, distribution, and threats. The specimens were observed on the forest floor and some perching in leaf litters and fallen logs in the forest patches. Numerous specimens were recorded in mountainous areas of Marilog District in Davao City (Figure 5a), Mt. Kitanglad in Lantapan (Bukidnon), and Mt. Malimumu in San Fernando (Bukidnon) (Figure 5b). These areas are considered secondary forests. The most recent collection of the species was on Mount Malimumu in San Fernando, Bukidnon (Figure 6). This area is composed of tropical lowland evergreen rainforest from c. 700–850 masl dominated by Shorea spp. The trail to summit at 700–1000 masl is a forest over ultramafic soil mostly covered with gravel having a high composition (80%) of a very common sedge (Themeda gigantea); bryophyte density (20%); leaf Figure 4. Pronotal spines of Misythus echinatus (Stål, 1877) showing litter (40%); an abundance of Nepenthes (100%); fallen the frontolateral (A), ventrolateral (B), promedial and logs (20%); exposed rocks (80%); and very common promediolateral (C), metalateral (D), metamediolateral pteridophytes such as Pteridium aquilinum (L.) Kuhn, (E), metamedial (F), lateral (G), and caudal (H) spines. Gleichenia hirta Blume, Lycopodiella cernua (L.) Pic.

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Table 1. Localities where Misythus echinatus is known in Mindanao, together with information on coordinates, elevation, date of researches, and reference for each. Locality Coordinates Elevation Date Collector/s Reference 1a) Dapa, Siargao Island Unknown Unknown 30 Feb 1916 W. Boettcher Hebard (1923) 1b) Bucas Islands Unknown Unknown Unknown W. Boettcher Hebard (1923) 1c) Surigao Unknown Unknown Unknown W. Boettcher from C.F. Hebard (1923) Baker 1d) Butuan, Agusan Unknown Unknown Unknown C.F. Baker Hebard (1923) 1e) Iligan, Misamis Unknown Unknown Unknown C.F. Baker Hebard (1923) 2a) Mt. Malimumu, Sitio 07°52’50.58”N, 1,074 masl August 2020 R.R. Patano Jr., A.B. Present study Nabangkal, Barangay 125°24’32.64”E Mohagan, and V.B. Magkalungay, San Fernando, Amoroso Bukidnon 2b) Mt. Ulahingan, Sitio 07°28’29.89”N, 1,300 masl February 2019 R.R. Patano Jr., A.B. Present study Tagumpay, Barangay Datu 125°16’36.77”E Mohagan, and V.B. Salumay Amoroso 2c) Mount Kitanglad Range, 08°06’29.54”N, 1,600 masl September 2018 R.R. Patano Jr., A.B. Present study Kaatuan, Lantapan, Bukidnon 124°56’0.61”E Mohagan, and V.B. Amoroso

Table 2. Measurements of collected specimens of Misythus echinatus from Bukidnon (1 and 2 – Mount Malimumu; 3 – Mount Kitanglad) and Davao Region (4 – Mount Ulahingan), and the male holotype specimen (5) from Semper’s collection available in the Orthoptera Species File website. N/A signifies no available measurement, as some morphological trait of the specimen has been broken. Females (N = 2) Males (N = 2) Male: holotype Body parameters 1 4 2 3 5 BL 18.0 17.8 14.4 14.45 14 PL 14.0 13.9 13.2 13.3 11.5 PLW 12.7 12.5 7.0 6.9 7.3 PH 7.3 7.0 6.65 6.7 5.7 FFL 4.1 4.0 3.5 3.65 3.5 FFW 1.9 1.7 1.3 1.25 1.35 MFL 5.0 4.8 4.0 3.85 4.5 MFW 2.0 1.9 1.9 1.95 1.6 HFL 8.1 7.9 7.5 7.7 8.0 HFW 4.0 3.8 3.5 3.6 3.75 VW 1.8 1.75 1.6 1.75 1.68 CEW 1.05 1.0 1.0 1.0 0.9 AL 8.8 8.6 6.3 6.4 N/A AnL 4.2 4.0 3.3 3.4 N/A

Serm., Dipteris conjugata Reinw., and Dicranopteris (1254 masl) with 80–100% bryophyte cover, fallen logs, linearis (Burm.f.) Underw. The tropical lower montane and an abundance of Nepenthes. Potential threats to rainforest at 1,000–1,100 masl is dominated by Casuarina biodiversity observed in the site were human activities equisetifolia L., Dacrycarpus sp., Leptospermum sp., and exploitations, i.e. illegal logging, mining, and habitat Dacrydium sp., and Falcatifolium gruezoi de Laub. burning for agriculture and human settlement. Besides the with high bryophyte cover (60%), leaf litter (60%), an Misamis, Butuan, and Surigao regions (Hebard 1923), abundance of Nepenthes (100%), fallen logs (80%), here we report the species from the Bukidnon and Davao and exposed rocks (20%). The tropical upper montane region. rainforest is located from 1,100 masl to the summit

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Figure 5. Misythus echinatus (Stål, 1877) (A and B) in its natural habitat perching on logs and fallen litter.

Figure 6. Habitat of Misythus echinatus (Stål, 1877): A) view on Mt. Malimumu (1,074 masl) and B) tropical upper montane forest where the examined specimens were collected.

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ACKNOWLEDGMENTS HEBARD M. 1923. The Philippine genus Misythus (Orthoptera, Acrididae, Acrydiinae). Proceedings of This study would like to thank the Department of the Academy of Natural Sciences of Philadelphia 75: Science and Technology Grants-in-Aid program 323–257. entitled “Biodiversity in Selected Mountain Ecosystems of Mindanao for Conservation and Sustainable MOHAGAN AB, LEAŃO EP, MELENCION MG, Development,” as well as the Commission on Higher PATANO JR. RP, HONGCO AL, AMOROSO VB. Education as the funding agency of our research in 2020a. Yellow Striped Giraffehopper Spartolus Marilog District entitled “Saving Terrestrial Biodiversity: pugionatus Stål, 1877 comb. resurr. (Tetrigidae: Inventory, Assessment, Conservation, and Capability Ophiotettegini) inhabits Mindanao Island of the Building in Marilog Forest Reserve, Southern Mindanao, Philippines’ archipelago. Zootaxa 4722(6): 591–600. Philippines”; the Department of Environment and Natural MOHAGAN AB, PATANO JR. RP, LEAŃO EP, Resources for the issuance of the GP; and the College of MELENCION MG, CORITICO FP, AMOROSO VB. Veterinary Medicine of Central Mindanao University, 2020b. Morphology and Morphometrics of Diotarus Musuan, Bukidnon for the issuance of IACUC permit. verrucifer (Stål, 1877), a Pygmy Grasshopper endemic to The research would not be possible without the valuable Mindanao. Philippine Journal of Science 149(3): 571–579. support of our University President Dr. Jesus Antonio G. Derije in implementing our research. Finally, the authors MOHAGAN AB, PATANO JR. RP, ACOLA MS, AMPER would like also to show appreciation to Josip Skejo for DO, CORITICO FP, AMOROSO VB. 2020c. Presence the identification of the specimens and for sharing his of the Four-spined Pygmy Devil, Arulenus validispinus knowledge on pygmy grasshoppers. (Orthoptera: Tetrigidae) confirmed in Bukidnon region on the island of Mindanao. Journal of Orthoptera 29(2): 133–136. MUHAMMAD AA, TAN MK, ABDULLAH NA, REFERENCES AZIRUN MS, BHASKAR D, SKEJO J. 2018. An BHASKAR D, STERMŠEK S, EASA PS, FRANJEVIĆ annotated catalogue of the pygmy grasshoppers of D, SKEJO J. 2020. Wide-nosed pygmy grasshoppers the tribe Scelimenini Bolívar, 1887 (Orthoptera: (Cladonotinae: Cladonotini, Xerophyllini) of India and Tetrigidae) with two new Scelimena species from the Sri Lanka: catalogue with an identification key and Malay Peninsula and Sumatra. Zootaxa 4485(1): 1–5. description of a new species of the genus Tettilobus. PATANO JR. RR, MOHAGAN AB, TUMBRINCK J, Zootaxa 4894(3): 474–500. AMOROSO AB, SKEJO J. 2021. Horned and spiky: BLACKITH RE. 1992. Tetrigidae (Insecta: Orthoptera) Tegotettix derijei sp. n. (Orthoptera: Tetrigidae) is of South-East Asia: annotated catalogue with partial a peculiar new pygmy grasshopper species from translated keys and bibliography. Wicklow: JAPAGA Mindanao. Zootaxa 4933(2): 198–210. Press. 248p. PELSER PB, BARCELONA JF, NICKRENT DL eds. BRUNER L. 1915. Preliminary catalogue of the 2011 onwards. Co’s Digital Flora of the Philippines. Orthopteroid of the Philippine Islands. Retrieved from www.philippineplants.org University Studies 15(2): 195–281 [1–87]. SKEJO J. 2017. Taxonomic Revision of the Pygmy Devils CASTO DE ELERA RPF. 1895. Ortópteros. Catálogo (Tetrigidae: Discotettiginae) with Online Social Media sistemático de toda la fauna de Filipinas. Monograph as a New Tool for Discovering Hidden Diversity. 2: 189–223. DOI: http://dx.doi.org/10.5962/bhl. Masters (Diploma) Thesis, University of Zagreb, title.58548 Zagreb, Croatia. 246p. CIGLIANO MM, BRAUN H, EADES DC, OTTE SKEJO J, BERTNER P. 2017. No More Dust and D. 2021. Orthoptera Species File. Version 5.0/5.0. Exoskeletons—In Vivo Photographic Records Provide Retrieved on 13 Jan 2021 from http://orthoptera. New Data on Eufalconius pendleburyi Günther, 1938 speciesfile.org/ (Orthoptera: Tetrigidae) from the Titiwangsa Mts. In Annales Zoologici 67(4): 665–673. GÜNTHER K. 1938. Revision der Acrydiinae, I. Sectiones Tripetalocerae, Discotettigiae, Lophotettigiae, SKEJO J, CABALLERO JHS. 2016. A hidden pygmy Cleostratae, Bufonidae, Cladonotae, Scelimenae verae. devil from the Philippines: Arulenus miae sp. nov.—a Mitteilungen aus dem Zoologischen Museum in Berlin new species serendipitously discovered in an amateur 23(2): 299–437. Facebook post (Tetrigidae: Discotettiginae). Zootaxa 4067(3): 383–393.

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