''Helophorus'' is the only genus in the

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

family Helophoridae (traditionally included within

Hydrophilidae Hydrophilidae, also known colloquially as water scavenger beetles, is a family of beetles. Aquatic hydrophilids are notable for their long maxillary palps, which are longer than their antennae. Several of the former subfamilies of Hydrophilidae ...

as the subfamily Helophorinae) within the

Hydrophiloidea Hydrophiloidea, known as water scavenger beetles, is a Taxonomic rank, superfamily of beetles. Until recently it included only a single family, the Hydrophilidae (water scavenger beetles), but several of the subfamilies have been removed and rais ...

. They are small insects, found mainly in the

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

region (150 occur in

Palearctic The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. Th ...

and 41 species in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

), but two or three species also live in the

Afrotropical The Afrotropical realm is one of the Earth's eight biogeographic realms. It includes Sub-Saharan Africa, the southern Arabian Peninsula, the island of Madagascar, and the islands of the western Indian Ocean. It was formerly known as the Ethiopi ...

region,

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

and one in the

Indomalayan The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia. Also called the Oriental realm by biogeographers, Indomalaya spreads all over the Ind ...

region (northern India).

Characteristics

Length about 2–9 mm. Body elongate with outline more or less interrupted between

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

and

elytra An elytron (; ; : elytra, ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometime ...

. On pronotum they have granulate sculpture and unique pattern of 7 longitudinal grooves. Ventral surface is with fine microsculpture, pubescent. Larvae are with long 3 segmented urogomphi and simple (non lobate) 8th tergum. They have four-segmented legs and a 10 segmented abdomen (with the 10th segment being a bit reduced).

Ecology

The majority of ''Helophorus'' species adults are aquatic live on the periphery of rivers and streams as well as stagnant bodies of water or pools, though a number are also terrestrial. Adults generally feed on decaying plant material, though some are known to feed on living plant tissue, with several species noted as pests of

turnips The turnip or white turnip ('' Brassica rapa'' subsp. ''rapa'') is a root vegetable commonly grown in temperate climates worldwide for its white, fleshy taproot. Small, tender varieties are grown for human consumption, while larger varieties a ...

. The larvae are terrestrial and are predominantly carnivores, though in some species are herviorous, and are pests of turnips,

rutabaga Rutabaga (; North American English) or swede (British English and some Commonwealth English) is a root vegetable, a form of ''Brassica napus'' (which also includes rapeseed). Other names include Swedish turnip, neep (Scots language, Scots), an ...

, and

wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...

Systematics and evolution

Helophoridae belong to the superfamily

, and may be the sister taxon of

Hydrochidae ''Hydrochus'' is the only living genus of beetle in the family Hydrochidae, which belongs to the superfamily Hydrophiloidea, and was formerly treated as a subfamily of Hydrophilidae. ''Hydrochus'' includes about 180 species, which are found worldw ...

, or a clade comprising

and

Spercheidae ''Spercheus'' is a genus of aquatic beetles which are placed in a family of their own, Spercheidae within the Hydrophiloidea. About 20 species are known from around the world except the Nearctic with the majority being from the Oriental and Afro ...

Georissidae ''Georissus'', also called minute mud-loving beetles, is the only genus in the beetle family Georissidae (or Georyssidae). They are tiny insects living in wet soil, often near water. They are found on every continent except Antarctica. Character ...

and

Epimetopidae Epimetopidae is a family of semi-aquatic beetles belonging to the Hydrophiloidea. They are found in sand and gravel at the edges of streams, rivers and shallow freshwater ponds. These beetles are shorter than half a centimeter long and have a pro ...

Helophorus oregonus ''Helophorus'' is the only genus in the beetle family Helophoridae (traditionally included within Hydrophilidae as the subfamily Helophorinae) within the Hydrophiloidea. They are small insects, found mainly in the Holarctic region (150 occur in ...

'' *'' Helophorus orientalis'' *'' Helophorus pallidipennis'' *'' Helophorus pallidus'' *'' Helophorus parajacutus'' *'' Helophorus paraminutus'' *'' Helophorus paramontanus'' *'' Helophorus paraspelendidus'' *'' Helophorus pitcheri'' *'' Helophorus ponticus'' *'' Helophorus poppii'' *'' Helophorus porculus'' *'' Helophorus pumilio'' *'' Helophorus redtenbacheri'' *'' Helophorus rinki'' *'' Helophorus robertsi'' *'' Helophorus rufipes'' *'' Helophorus schoedli'' *'' Helophorus schuhi'' *'' Helophorus sempervarians'' *'' Helophorus sibiricus'' *'' Helophorus similes'' *'' Helophorus smetanai'' *'' Helophorus splendidus'' *'' Helophorus strandi'' *'' Helophorus strigifrons'' *'' Helophorus subarcuatus'' *'' Helophorus subcarinatus'' *'' Helophorus syriacus'' *'' Helophorus terminassianae'' *'' Helophorus tuberculatus'' *'' Helophorus tumidus'' *'' Helophorus uvarovi'' *'' Helophorus zagrosicus''

References

{{Taxonbar, from=Q675909 Hydrophiloidea Staphyliniformia genera