order
![](/images/illustrations/illustration_coleoptera_adult_v_160.png)
Coleoptera
“Adult Beetles”
![](/images/illustrations/illustration_coleoptera_larva_v_160.png)
Coleoptera
“Larval Beetles”
![](/images/illustrations/illustration_diptera_larva_v_160.png)
Diptera
“True Flies”
![](/images/illustrations/illustration_ephemeroptera_larva_v_160.png)
Ephemeroptera
“Mayflies”
![](/images/illustrations/illustration_hemiptera_adult_v_160.png)
Hemiptera
“True Bugs”
![](/images/illustrations/illustration_lepidoptera_larva_v_160.png)
Lepidoptera
“Aquatic Caterpillars, Snout Moths”
![](/images/illustrations/illustration_megaloptera_larva_v_160.png)
Megaloptera
“Alderflies, Dobsonflies, and Fishflies”
![](/images/illustrations/illustration_odonata_larva_v_160.png)
Odonata
“Dragonflies and Damselflies”
![](/images/illustrations/illustration_plecoptera_larva_v_160.png)
Plecoptera
“Stoneflies”
![](/images/illustrations/illustration_trichoptera_larva_v_160.png)
Trichoptera
“Caddisflies”
family
Dytiscidae
“Predacious Diving Beetles”
Genus Overview
Larvae and adults occur in slow-moving streams and among rooted plants of lentic habitats; both life stages are piercing predators. Adults are efficient swimmers and divers.
Characteristics
POLLUTION TOLERANCE
Southeast: 9.1 and higher
Midwest: 5 and higher
Mid-Atlantic: 5 and higher
0 = least tolerant, 10 = most tolerant
FEEDING HABITS
Piercer / Predator
MOVEMENT
Diver
Swimmer
Swimmer
DISTRIBUTION
Widespread (east of the Rocky Mtns.)
HABITAT
Lentic-littoral
Lotic-depositional
Lotic-depositional
Diagnostic Characters
Order
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-120x120-3477-8910-870-6303.jpg)
Elytra
Family
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-120x120-3452-8146-1611-6304.jpg)
Coxal Plate Not Wedge-like
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-120x120-3452-8146-1611-6304.jpg)
Extended Hind Coxae
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-120x120-1720-9365-0-7645.jpg)
Large Spurs Absent
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-120x120-2883-4140-2969-4226.jpg)
Scutellum Usually Visible
+ Expanded Character List
Order:
Adults with hardened forewings (elytra) covering the hind wings.
Family:
Ventrally, pronotum with conspicuous curved lines near each lateral margin (notopleural sutures). Metasternum without transverse sutures. Elytra covering entire abdomen or exposing only part of 1 tergite. Hind coxae each with median portion extending in posterior direction, dividing abdominal segment 1 into lateral sclerites, but not expanding into broad plates. Without large spur on end of each front tibia. Dyticidae without broad wedge-like hind coxal plate. Scutellum usually visible; if hidden, then front and middle tarsi apparently 4-segmented and hind tarsi each with 1 claw. Hind tarsi and usually tibiae flattened, streamlined, and bearing long, stiff swimming bristles. Body usually 3–25 mm long.
Genus:
Smaller beetles 3.5-5.0 mm long. Elytra with longitudinal striae. Metacoxal lines strongly convergent and almost contacting medial line anterior of metacoxal lobes, then diverging anteriorly. Metafemora lacking groups of setae at posteroapical angles.
![](https://static.macroinvertebrates.org/gigapans/198542/images.ec3fa3c356c7b57baad3a5f2e918faad/198542-348x240.jpg)
Dorsal