order
Coleoptera
“Adult Beetles”
Coleoptera
“Larval Beetles”
Diptera
“True Flies”
Ephemeroptera
“Mayflies”
Hemiptera
“True Bugs”
Lepidoptera
“Aquatic Caterpillars, Snout Moths”
Megaloptera
“Alderflies, Dobsonflies, and Fishflies”
Odonata
“Dragonflies and Damselflies”
Plecoptera
“Stoneflies”
Trichoptera
“Caddisflies”
family
Gyrinidae
“Whirligig Beetle Larvae”
Genus Overview
This genus includes about 41 species in North America North of Mexico, and is widespread across eastern Noth America. Gyrinus includes most of the smaller species in the Gyrinidae family, while Dineutus contains the larger species. In order to deter predators, members of the genus Gyrinus often give off a foul smell and taste when disturbed. Adults and larvae prefer lotic-depositional habitats along the margins and pools of flowing water. Both larvae and adults are engulfing predators, and scavengers of small organisms, however, unlike the larvae, the adults usually hunt at the water’s surface.
Characteristics
POLLUTION TOLERANCE
Southeast: 6.3 and higher
Midwest: 3.6 and higher
Mid-Atlantic: 4 and higher
FEEDING HABITS
Engulfer / Predator
MOVEMENT
Climber
Sprawler
Swimmer
Sprawler
Swimmer
DISTRIBUTION
Widespread (east of the Rocky Mtns.)
HABITAT
Lentic-littoral
Lotic-depositional
Lotic-depositional
Diagnostic Characters
Order
Eye Spots
Lateral Gills USUALLY Absent
USUALLY 4-5-Segmented Legs
Family
4 Posterior Hooks
5-Segmented Legs + Claws
Lateral Gills
Genus
Head without a collar
+ Expanded Character List
Order:
Larvae: Usually without lateral abdominal gills. If gills present, then 4 hooks clustered on segment 10. Thoracic legs each usually with 4 or 5 segments and with 1 or 2 claws; if without legs, head distinctly sclerotized and posterior body (thorax and abdomen) simple, without gills, hair brushes, suckers, or breathing tube. Eye spots usually present, but compound eyes absent.
Family:
Legs 5-segmented plus 2 tarsal claws. Abdominal segments 1–9 with lateral gills. Abdominal segment 10 (posterior-most segment) with 4 stout hooks.
Genus:
Nasale (anterior most margin of the face) with 2-4 teeth measly along margin. Head elongate, with the collum (neck) nearly as wide as rest of head.
Dorsal
Ventral