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 Beetles”
               
      Genus Overview
                  
               
                        This is a large and widespread genus with 41 species in North America. Adults are swimmers on the water surface (neuston) and divers in lentic habitats and slower parts of streams, scavengers and predators of small insects. 
Adult members of the genus Gyrinus often emit a bad smell and taste in order to deter predators.
               Adult members of the genus Gyrinus often emit a bad smell and taste in order to deter predators.
Characteristics
                  
               POLLUTION TOLERANCE
                        Southeast: 6.3 and higher
                                 Midwest: 3.6 and higher
                                 Mid-Atlantic: 4 and higher
                              0 = least tolerant, 10 = most tolerant
                        FEEDING HABITS
                        
                                 Engulfer / Predator
                        
                     MOVEMENT
                        
                                 Diver
Swimmer
                        
                     Swimmer
DISTRIBUTION
                        
                                 Widespread (east of the Rocky Mtns.)
                        
                     HABITAT
                        
                                 Lentic-littoral
Lotic-depositional
                        
                     Lotic-depositional
Diagnostic Characters
               order
                         
                                       
                                       
                                    Elytra
                                 family
                         
                                       
                                       
                                    4 Eyes
                                 genus
                         
                                       
                                       
                                    Scutellum
                                 
                  + Expanded Character List
                  
                     
               
            
                        Order:
                           Adults with hardened forewings (elytra) covering the hind wings. 
                     
                     
                        Family:
                           Short antennae with clubbed apices. Compound eyes divided into separate dorsal and ventral portions ("4-eyed" appearance). 
                     
                     
                        Genus:
                           Dorsal and ventral compound eyes divided (“four-eyed” appearance). Upper eyes are separated from lateral margin of head by a distance equal to half the width of eye or more. Pronotum and elytron entirely glabrous (without hair). Each elytron with 11 conspicuous striae. Scutellum exposed, not covered or obscured. Meso- and metatarsal segments 2, 3, and 4 are much wider than long. Body relatively small, about 4-7 mm in length.
                     
                   
                   
                   
            Dorsal
               Lateral
               Ventral
               


