Schedorhinotermes medioobscurus ( Holmgren, 1914 )

Takematsu, Yoko & Vongkaluang, Charunee, 2012, A taxonomic review of the Rhinotermitidae (Isoptera) of Thailand, Journal of Natural History 46 (17 - 18), pp. 1079-1109 : 1101-1103

Schedorhinotermes medioobscurus ( Holmgren, 1914)

( Figures 11A–J , 14E )

Rhinotermes (Schedorhinotermes) brevialatus f. medioobscurus Holmgren, 1914: 241 .

Schedorhinotermes medioobscurus, Snyder, 1949: 94 .

Rhinotermes (Schedorhinotermes) tarakanensis Oshima, 1914: 564 , pl.10, fig.2.

Schedorhinotermes tarakanensis, Roonwal and Maiti, 1966: 91 . Synonymized by Gathorne-Hardy, 2004: 92.

Schedorhinotermes javanicus Kemner, 1934: 51–54 , fig.7. Synonymized by Gathorne- Hardy, 2004: 92–93.

Material examined

THAILAND: Chiang Mai: two series, Doi Inthanon National Park , 1100 m alt., 5 September 1997, Y. Takematsu coll. ; Petchabun: Tung Salang Luang Nationak Park , 8 April 1962, M. Ahmad coll. [NHML]; Sakhon Nakhorn: Phu Phan National Park , 550 m alt., 23 August 2003, Y. Takematsu coll. ; Nakhorn Ratchasima: Nakhorn Ratchasima , 1 November 1999, Y. Takematsu coll. ; three series, Sakaerat Environmental Research Station , 20 August 1997, Y. Takematsu coll. ; Sakaerat Environmental Research Station, 21 Jaunary 1998, I. Tayasu coll. ; five series, Khao Yai National Park , 700 m alt., 1 December 1998, Y. Takematsu coll. ; Trat: Koh Kood , 14 March 1997, Y. Sornnuwat coll. ; Prachuap Khiri Khan: Namtok Huai Yang National Park , 300 m alt., 7 November 2002, Y. Takematsu coll. ; Surat Thani: four series, Khao Sok National Park , 400 m alt., 4 November 2002, Y. Takematsu coll. ; Phuket: two series, Bang Kanoon , Phuket Is., 11 November 1998, Y. Sornnuwat coll. ; Bang Kanoon , Phuket Is., 3 November 2002, Y. Takematsu coll. ; Narathiwat: three series, Hara Bara Wildlife Sanctuary , 300 m alt., 29 May 1997, Y. Takematsu coll. ; Phu To Deang , 31 May 1997, Y. Takematsu coll. ; Narathiwat , 25 September 1995, Y. Sornnuwat coll.

Diagnosis

Major soldier. Small species. Head subtriangular to subrectangular, widest at posterior third and moderately narrowed anteriorly, sparsely hairy on head capsule. Eyes present, but small and whitish. Inner edge of apical tooth of left mandible convex; the basal part of the right mandible with a distinct step. Antennae with 15–17 segments.

Minor soldier. Small species. Head widest at posterolateral end of antennal sockets and slightly narrowed posteriorly, with several hairs on head capsule. Eyes present, oval, but whitish and faint. Apical tooth short and weakly incurved, DAM1 / DM1M2 1.13–1.27 (1.21). Antennae with 15–16 segments. Postmentum without a projection, smoothly arched in lateral view.

Measurements (mm)

Major soldier. 40 soldiers from 20 series: HL, 1.28–1.82 (1.56); mHW, 1.26–1.68 (1.47); LML, 0.99–1.08 (1.03); PL, 0.50–0.60 (0.57); PW, 0.90–1.10 (0.96); PosL, 1.06–1.20 (1.10); PosW, 0.44–0.52 (0.48) .

Minor soldier. 15 soldiers from five series: HL, 0.82–0.87 (0.83); mHW, 0.69–0.78 (0.74); LML, 0.56–0.65 (0.61); PL, 0.37–0.42 (0.40); PW, 0.54–0.67 (0.59); PosL, 0.54–0.63 (0.60); PosW, 0.29–0.33 (0.31) .

Distribution

Thailand, Cambodia, Vietnam, India, Peninsular Malaysia, Sumatra, Borneo, Java.

Remarks

This species is widely distributed in Southeast Asia including throughout Thailand. The Schedorhinotermes species in the Indomalayan region have been separated by size, head shape and the number of antennal segments. However, these characters are variable and overlap. Gathorne-Hardy (2004) observed many specimens and concluded that javanicus and tarakanensis were junior synonyms of S. medioobscurus .

This species is similar to rectangularis in size, but easily distinguished by the sparsely hairy head of the major soldier, and shorter apical teeth on the minor soldier.

Figures

Figure 11. Soldier of Schedorhinotermes medioobscurus (Holmgren). (A) Head of major soldier, dorsal view; (B) head of major soldier, lateral view; (C) pronotum of major soldier; (D) postmentum of major soldier; (E) mandibles of major soldier; (F) head of minor soldier, dorsal view; (G) head of minor soldier, lateral view; (H) pronotum of minor soldier; (I) postmentum of minor soldier; (J) mandibles of minor soldier. Scale bar 0.5 mm.

Figure 14. Distribution of Parrhinotermes, Prorhinotermes and Schedorhinotermes in Thailand. (A) Parrhinotermes buttelreepeni; (B) Parrhinotermes microdentiformisoides; (C) Prorhinotermes flavus; (D) Schedorhinotermes malaccensis; (E) Schedorhinotermes medioobscurus; (F) Schedorhinotermes rectangularis.