![]() Some large species live up to several years and move to larger water bodies to overwinter. This takes place when the competition for food is too high, when looking for mates, or if conditions in the habitat dramatically change (becomes polluted, dries out, freezes). They use light reflections from the water surface to detect new habitats. Moreover, diving beetles kept the ability to fly and thus colonize new locations. It is advantage over other invertebrates, protecting the beetles from predators and mechanical damage. Head, thorax and bottom side of the abdomen are hardened (sclerotized) as well. Forewings are modified into hardened covering (elytra), which protects the top of abdomen and the second pair of membranous wings. These adaptations make dytiscids exceptionally efficient swimmers.Īs like in terrestrial beetles, all the body is well armored. Other four legs are trucked into grooves along the sides to preserve streamlined body shape. On the return stroke they bend in to reduce water resistance. The hairy fringes spread out on the power stroke, which increase the surface area. Hind legs are equipped with dense rows of swimming hairs. In general, the body is more streamlined in shape and flattened (compared to terrestrial beetles). Adults and larvae rely on atmospheric oxygen, therefore can be found even in habitats with low level of dissolved oxygen.ĭiving beetles may look very similar to their terrestrial relatives, but dytiscids have developed some modifications, which enable them to be so successful and diverse. The greatest diversity is reached in still waters such as ponds, wetlands, billabongs, or in slow flowing waters with lot of vegetation. Beetles entered aquatic environment after millions of years evolving on land, yet they can be found in almost any freshwater habitat. One third of all insects belongs to this single order.Įven though most beetles are terrestrial, many of them have colonized freshwater habitats and spend at least one of their life stages as aquatic. In diversity, Coleoptera is the largest order of insects (containing more than 400 000 described species) and one of the largest groups of animals on Earth. Most species produce one generation per year. Their life cycle includes four stages – egg, larva, pupa and adult. Size of the adult diving beetles varies from 2 mm to 45 mm.ĭiving beetles undergo complete metamorphosis. They are common in temporary pools, wetlands, marshes, ponds and slow sections of flowing waters. Although the site is protected from development, the quantity and quality of groundwater entering the inhabited stream is of greater concern for the beetle’s continued survival.Diving beetles can be found in almost any freshwater habitat. After pupating, the adult beetle is winged and can fly short distances but soon returns to water and loses the ability to fly. The larva possesses gills at the tip of its abdomen and may remain at this stage for 2-3 years. The rocks provide the surface area where it grazes on diatoms and periphyton. A short stretch of spring-fed stream is home to this diminutive beetle (0.1 inch length) which can be found clinging to rocks. The Scott optioservus riffle beetle lives in cool water with a high concentration of dissolved oxygen. Common Name: Scott Optioservus Riffle Beetleĭark Blue = Counties with designated critical habitatĬomments: The only known place in the world where the Scott optioservus riffle beetle can be found is at Scott State Park.
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