The Gyrinidae (Coleoptera) fauna of Thailand: Key to tribes and genera, with new records and keys to species of Dineutini and Gyrinini
Suksai, Benjamart
Gustafson, Grey T.
Sites, Robert W.
Sangpradub, Narumon
Zootaxa
2021
2021-11-22
5071
1
97
117
(Fabricius, 1775)
Fabricius
1775
[151,593,223,250]
Insecta
Gyrinidae
Dineutus
Animalia
Coleoptera
6
103
Arthropoda
species
australis
( Figs. 1C–D, 4A, 5A–E, 7C, 8A)
Material examined. THAILAND: Chiang Mai Province: Doi Inthanon Natl. Park, Mae Klang Waterfall, 18°29'N 98°40'E, 415 ma.s.l., 3.IV.2002, leg. CMU Team, 1 female( GTGC). Khon Kaen Province: Chum Pae District, 16°34.585'N 102°01.668'E, 415 ma.s.l., 3.V.2004, leg. A. Vitheepradit, L-660, 1 female( GTGC). Nakhon Ratchasima Province: Sakaerat Environmental Research Station, Bonweir, U-dom Sap Subdistrict, Wang Nam Khiao District, 14°29'49.2"N 101°54'55.5"E, 472 ma.s.l., 22.II.2014, leg. B. Suksai, 1 male( KKU); same locality except for, 29.III.2018, leg. P. Chanteenok, 1 female( KKU); same locality except for, 8.IV.2018, leg. B. Suksai, O. Pornsophon, T. Jantaranakee& S. Phengsalung, 2 males, 2 females( THNHM). Phang Nga Province: Ban Bang Klag Klang, Koag Kien Subdistrict, Takua Pa District, 8°52.469'N 98°22.679'E, 17 ma.s.l., 4.I.2006, leg. A. Vitheepradit, R.W. Sites& T. Prommi, L-881, 1 male( UMC). Prachuap Khiri Khan Province: Ban Fah Pa Tarn, Hua Hin District, 12°31.810'N 99°32.062'E, 149 ma.s.l., 28.V.2004, leg. A. Vitheepradit& T. Prommi, L-723, 1 male( UMC); same locality except for, Bue Sawan Stream, Huay Yang Subdistrict, Thap Sakae District, 11°40'29.4"N 99°36'02.4"E, 208 ma.s.l., 23.V.2017, leg. B. Suksai& C. Yatfung, 1 female( THNHM).
Diagnosis.Male ( Fig. 1C): Size: 7.6–8.2 mm. Body form oval; apex of flagellomere VI darkly colored; elytral apices obliquely truncate with epipleural spines and serrations present ( Figs. 1C, 5A); lateral marginal of pronotum and elytron black to brown; protrochanter apically with patch of thick setae on ventral surface ( Fig. 4A); profemur without sub-apicoventral tooth; protibia wedge-shaped; venter black, epipleura brownish; aedeagus ( Figs. 5C–D) with median lobe slightly shorter than parameres, swollen in basal 1/9, strongly narrowed after basal 1/9, apex with tip strongly pointed, weakly curved ventrally in lateral view. Female ( Fig. 1D): Similar to male except for size: 8.1–8.2 mm; elytral apices truncate without epipleural spines ( Figs. 1D, 5B), protrochanter apically without patch of thick setae on ventral surface; gonocoxae ( Fig. 5E) elongate, lateral margin expanded and weakly rounded, apex nearly straight. Differential diagnosis. Dineutus australisis closest to D. unidentatus, which also is found in Thailand, and can be distinguished from all other species of Dineutusin this country by the protrochanter of the male having a distinct patch of setae. Both sexes of D. australiscan be distinguished from those of D. unidentatusby the oval body form and larger size, whereas in D. unidentatusthe body is narrowly oval ( Fig. 1G) and smaller (6.0– 6.9 mm). The elytral apices of males of D. australishave weak epipleural spines, whereas in the males of D. unidentatusthese are longer and more developed ( Fig. 6A). In dorsal view, the aedeagus of D. australisis distinct from that of D. unidentatus, as the median lobe is very narrow and without a constricted apex ( Fig. 5C), in comparison to the broader, more parallel-sided median lobe of D. unidentatus, which is abruptly constricted at its apex ( Fig. 6B). The females of D. australiscan be distinguished from those of D. unidentatusby the elytral apices lacking epipleural spines, which are presented in D. unidentatus. The reproductive tract of D. australishas broader gonocoxae with the apex nearly straight, whereas in D. unidentatusthe gonocoxae are more elongate, with the apex obliquely truncate and the lateral angle acuminate.
Distribution. This species is widely distributed in the Oriental and Australian Regions. It has been recorded from China, Taiwan( Mazzoldi 1995); the Philippines( Ochs 1924; Freitag et al.2016); Japan( Takizawa 1931); Indonesia( Ochs 1949, 1953): Java, Bali, Lombok, Sumba, Sulawesi, Buru; New Guinea( Ochs 1955), Australia( Ochs 1949; Watts & Hamon 2010); New Caledonia( Satô 1966; Mazzoldi 2010); and the Pacific Islands: Vanuatu( Watts & Hamon 2010) and Fiji( Ochs 1949). This is the first time it has been recorded in Thailand. Habitat.In Australia, D. australishas been found in reservoirs, swamps, and pools in rivers and streams ( Watts & Hamon 2010). In the present study, BS collected D. australison the water surface of ponds in the forest ( Fig. 7C) where it occurred among aquatic plants in shallow water. Additionally, it was found in shallow, stagnant streams.
Discussion.Within Thailand, it was found in the northern, northeastern, western, and southern regions ( Fig. 8A) and was collected at low elevations ranging from 17–472 ma.s.l. It co-occurred with D. unidentatusand D. spinosusin ponds.
3411799381
2002-04-03
GTGC
Team
Thailand
415
18.483334
Mae Klang Waterfall
1275
98.666664
Doi Inthanon Natl. Park
6
103
1
1
Chiang Mai
3411799410
2004-05-03
GTGC
A. Vitheepradit
Thailand
415
16.576416
Chum Pae District
1
102.0278
6
103
1
1
Khon Kaen
3411799353
2014-02-22
KKU
B. Suksai
Thailand
Sakaerat Environmental Research Station
472
14.497001
Sap Subdistrict
1
101.91542
Bon
6
103
1
1
Nakhon Ratchasima
3411799360
2018-03-29
KKU
P. Chanteenok
Thailand
Sakaerat Environmental Research Station
472
14.497001
Sap Subdistrict
1
101.91542
Bon
6
103
1
1
Nakhon Ratchasima
3411799345
2018-04-08
THNHM
B. Suksai & O. Pornsophon & T. Jantaranakee & S. Phengsalung
Thailand
Sakaerat Environmental Research Station
472
14.497001
Sap Subdistrict
1
101.91542
Bon
6
103
4
2
2
Nakhon Ratchasima
3411799406
2006-01-04
UMC
A. Vitheepradit & R. W. Sites & T. Prommi
Thailand
Ban Bang Klag Klang
17
8.874483
Takua Pa District
1
98.37798
Koag Kien Subdistrict
6
103
1
1
Phangnga
3411799347
2004-05-28
UMC
A. Vitheepradit & T. Prommi
Thailand
149
12.530167
Hua Hin District
1
99.53437
Ban Fah Pa Tarn
6
103
1
1
Prachuap Khiri Khan
3411799436
2017-05-23
THNHM
B. Suksai & C. Yatfung
Thailand
Bue Sawan Stream
208
11.674833
Thap Sakae District
1
99.60066
Huay Yang Subdistrict
6
103
1
1
Prachuap Khiri Khan