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Genus Rhantus

predacious diving beetle - Rhantus gutticollis predacious diving beetle - Rhantus gutticollis Predaceous Diving Beetle- Rhantus binotatus - Rhantus binotatus - male Dytiscid - Rhantus consimilis - female water beetle - Rhantus gutticollis Predaceous Diving Beetle - Rhantus binotatus Water Far Away - Rhantus gutticollis Rhantus species? - Rhantus consimilis
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Adephaga (Ground and Water Beetles)
Family Dytiscidae (Predaceous Diving Beetles)
Subfamily Colymbetinae
Tribe Colymbetini
Genus Rhantus
Explanation of Names
Rhantus Dejean 1833
in our area, 10 spp., 7 of which are found in Canada and Alaska(1)
8.5-16 mm
eyes notched at antennal bases
no row of setae on ventral posteroapical angle of hind femur
hind tarsal claws unequal
elytra sculpture with various degrees of reticulation (in similar genus Colymbetes, elytra sculpture consists of transverse parallel grooves)
head and pronotum variously patterned with black markings/blotches; overall colour ranges from yellow brown to black
The individual species can be distinguished from each other by differences in the black maculation of the head and pronotum, absence/presence of pronotal spots and also colour of the elytron.
holarctic; throughout North America
wide range of habitats; in both standing and running water, also bogs, springs, and even saline ponds
Life Cycle
Univoltine; adults overwinter and breed in spring; larvae develop in spring and summer and emergent adults dispersing to overwintering sites in late summer and fall(1)
2 subgenera, of which Nartus is represented in NA by R. sinuatus(1)
Internet References
quality images of 4 spp. (pinned specimens)