Water scavenger beetles

Code QC110000

Morphologically, the Hydrophilidae are quite diverse, and include several groups previously regarded as separate families (Georissinae ( Georissus ), Berosinae, Spercheinae and the remainder).

Larval hydrophilid body forms range from elongate and parallel sided to ovate, body size ranging from 1.5mm to 60mm when mature. The antennae are moderate to very long, with 3-4 segments. All hydrophilids have 5 segmented legs with a single claw (tarsungulus), except for Georissinae which have three segmented legs, which readily distinguishes them from dytiscid, carabid and other grossly similar adephagan larvae which have six segmented legs with paired claws. Abdominal terga 8 and 9 form a spiracular chamber housing the enlarged 8th spiracles in all hydrophilids except Berosinae and Georissinae, which also distinguishes them from other Coleoptera. Berosinae possess paired gills on abdominal segments 1-7, Spercheinae possess conical gill-like projections on abdominal segments 1-8, the remaining hydrophilid groups lack gills or other lateral abdominal projections. Urogomphi are long and slender to short and stout.

Most larval hydrophilids (Polyphaga: Hydrophiloidea) are fully aquatic, occurring in a wide range of lentic and lotic habitats, though shallow weedy margins of ponds, stream banks and lakes are most favoured. Some are more semi-aquatic, occurring in riparian habitats. In contrast with the adults, which are phytophagous or saprophagous, larval hydrophilids are mostly voracious predators. Hydrophilids occur in all Australian states, with approximately 175 species currently recognised.

References:

Lawrence, J.F. and Britton, E.B. (1991) Coleoptera. pp. 543-683. In: CSIRO, Insects of Australia. Volume 2. Melbourne University Press, Carlton, Victoria.

Spangler, P.J. (1991a) Hydrophilidae (Hydrophiloidea) pp. 355-358. In: Stehr, F.W. (ed.) Immature Insects. Volume 2. Kendall/Hunt Publishing Company, Dubuque, Iowa.

Spangler, P.J. (1991b) Georyssidae (Hydrophiloidea) pp. 358-359. In: Stehr, F. W. (ed.) Immature Insects. Volume 2. Kendall/Hunt Publishing Company, Dubuque, Iowa.