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
                        
                     Dytiscidae
               
            
                  “Predacious Diving Beetle Larvae”
               
      Genus Overview
                  
               
                        This large genus includes 106 species in North America. Adults and larvae inhabit both fast and slow streams and littoral zones of lentic habitats. They are piercing predators.
                  
               Characteristics
                  
               POLLUTION TOLERANCE
                        Mid-Atlantic: 8 and higher
                              0 = least tolerant, 10 = most tolerant
                        FEEDING HABITS
                        
                                 Piercer / Predator
                        
                     MOVEMENT
                        
                                 Sprawler
Swimmer
                        
                     Swimmer
DISTRIBUTION
                        
                                 Widespread (east of the Rocky Mtns.)
                        
                     HABITAT
                        
                                 Lentic-littoral
Lotic-depositional
Lotic-erosional
                        
                     Lotic-depositional
Lotic-erosional
Diagnostic Characters
               order
                         
                                       
                                       
                                    Eye Spots
                                  
                                       
                                       
                                    Lateral Gills USUALLY Absent
                                  
                                       
                                       
                                    USUALLY 4-5-Segmented Legs
                                 family
                         
                                       
                                       
                                    5-Segmented Swimming Legs
                                  
                                       
                                       
                                    8-Segmented Abdomen
                                  
                                       
                                       
                                    Sickle-Shaped Mandibles
                                 
                  + 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:
                           Larvae approximately 5–70 mm long. Sickle-shaped mandibles without mola (grinding surface). Long, slender swimming legs 5-segmented, excluding 2 claws. Abdomen 8-segmented, lacking hooks on terminal segment, usually without gills. Roughly cylindrical thorax and abdomen tapered to anterior and posterior ends. Cerci (urogomphi) usually 2-segmented, slender and longer than abdominal segment 1, but can be stout, short, inconspicuous, or absent. 
                     
                     
                        Genus:
                           Mandibles without large and distinct teeth along inner margins. Maxillary galea finger-like. Urogomphi each usually 2-segmented. Tibiae and tarsi with or without swimming hairs.
                     
                   
                   
            Dorsal
               Ventral
               


