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
                        
                     Hydrophilidae
               
            genus
                        
                     Tropisternus
            
                  “Water Scavenger Beetles”
               
      Genus Overview
                  
               
                        This widespread genus includes 14 North American species. Adults and larvae occur in slow streams and lentic habitats. Adults are swimmers, divers, and climbers that feed as piercing herbivores and as collectors-gatherers of small bits of organic matter.
                  
               Characteristics
                  
               POLLUTION TOLERANCE
                        Southeast: 9.8 and higher
                                 Mid-Atlantic: 10 and higher
                              0 = least tolerant, 10 = most tolerant
                        FEEDING HABITS
                        
                                 Collector / Gatherer
Piercer / Herbivore
                        
                     Piercer / Herbivore
MOVEMENT
                        
                                 Climber
Diver
Swimmer
                        
                     Diver
Swimmer
DISTRIBUTION
                        
                                 Widespread (east of the Rocky Mtns.)
                        
                     HABITAT
                        
                                 Lentic-littoral
Lotic-depositional
                        
                     Lotic-depositional
Diagnostic Characters
               order
                         
                                       
                                       
                                    Elytra
                                 family
                         
                                       
                                       
                                    5 Segments Before Cupule
                                  
                                       
                                       
                                    Antenna Subequal To Head
                                  
                                       
                                       
                                    Antennal Segment Articulation
                                  
                                       
                                       
                                    Clubbed Antennae
                                  
                                       
                                       
                                    Long Maxillary Palpi
                                 
                  + Expanded Character List
                  
                     
               
            
                        Order:
                           Adults with hardened forewings (elytra) covering the hind wings. 
                     
                     
                        Family:
                           Maxillary palpi usually longer than antennae. Antennae about as long as head, with 2nd segment attached at apex of 1st (basal-most) segment; usually with 5 segments before cupule (cup-shaped, hairless, segment 6); segments 7–9 clubbed. Pronotum usually not narrower than elytra; if narrower, then scutellum long and triangular. Elytra concealing entire abdomen or exposing only part of 1 segment. Hind coxae not extending in the posterior direction to divide abdominal sternite 1. Metacoxae nearly touching. Ventrally, longitudinal keel narrow between coxae. Tarsal formula: 5-5-5 or 5-4-4. Ventrally, abdomen with 5 visible segments.
                     
                     
                        Genus:
                           Adults are usually less than 12 mm in length. The prosternum has a small longitudinal groove. The meso- and metasternum has a long, continuous, sharp spine extending between the hind coxae.
                     
                   
                   
            Dorsal
               Ventral
               


