Spercheus stangli Schwarz & Barber, 1917

Hendrich, Lars & Balke, Michael, 2004, Aquatic Coleoptera Of Singapore: Species Richness, Ecology And Conservation #, Raffles Bulletin of Zoology 52 (1), pp. 97-145 : 123

Spercheus stangli Schwarz & Barber, 1917

( Fig. 26 )

Spercheus Stangli Schwarz & Barber, 1917: 133 .

Spercheus stangli Schwarz & Barber - D’Orchymont, 1919: 70; Hebauer, 1997: 22; Hansen, 1999: 67, and references therein.

Material examined. – 2 specimens - Other areas - 2 ex., Kranji fish pond near Neo Tiew Road, 12 Oct.1990, coll. C. M. Yang ( ZRC) .

Distribution. – Sri Lanka, Cambodia, Thailand, Brunei, Philippines [Luzon] ( Hebauer, 1997). First record for the Malaysian Peninsula and Singapore!

Ecology. – A lentic species which occurs in shallow and exposed swamps and ponds, rich in aquatic vegetation and plant debris.

FAMILY HYDROPHILIDAE

This rather large family comprises about 2400 described species. Around 400 species in 60 genera are reported from the Oriental realm ( Hansen, 1999). Adult and larval hydrophilids have very different habits; the former are phytophagous or saprophagous, while the latter are predacious. Most members of the subfamily Sphaeridiinae are strictly terrestrial (except for the aquatic genus Coelostoma ), living in decaying vegetable matter, dung, carrion, damp soil and ant or termite nests ( Hansen, 1999). Like the Dytiscidae , the aquatic hydrophilids inhabit all kinds of freshwater habitats. Most of the aquatic species are oval to globose, smooth and glabrous, often resembling Dytiscidae , from which they differ in having short and clubbed antennae and long maxillary palps. A ventral plastron, which communicates with a small subelytral air reservoir, is also present. When the beetle rises to the surface, it breaks the surface film using its specialised antennal club, allowing communication between atmosphere and plastron (Lawrence & Britton, 1991). The plastron is held by a fine, golden setation, or hydrofuge pubescence, which covers the major part of the beetle’s venter.

SUBFAMILY HYDROPHILINAE

TRIBE BEROSINI

Figures

Figs. 24-30. 24. Cybister sugillatus Erichsin, 1834 (Fam. Dytiscidae, 22.0 mm); 25 Hydrocanthus indicus Wehncke, 1876 (Fam. Noteridae, 4.5 mm); 26. Spercheus stangli Schwarz & Barber, 1917 (Fam. Spercheidae, 4.2 mm); 27. Berosus fairmairei Zaitzev, 1908 (Fam. Hydrophilidae, 4.5 mm); 28. Amphiops mater sumatrensis (Sharp, 1873) (Fam. Hydrophilidae, 3.5 mm); 29. Helochares pallens (MacLeay, 1825) (Fam. Hydrophilidae, 3.1 mm);30. Hydrophilus cavisternum Bedel, 1891 (Fam. Hydrophilidae, 32.0 mm).