Coleoptera392 species

Family Predaceous Diving Beetles (Dytiscidae)

Dytiscidae is a family in the order Coleoptera. Browse 392 named species recorded in this family, or open an individual profile for its available identification and natural-history information.

Species in Dytiscidae (392)

Acilius abbreviatus

Identification: Similar to A. semisulcatus , differs in the appearance of the subapical white band, which is broadened laterally at the elytral suture (±complete arc in A. semisulcatus ). It is also the only Acilius reported from the far west. ―Tim L

Acilius confusus

Identification: Head rufous with indistinct black M-shaped macula

Acilius sulcatus

A large water beetle with considerable colour variation. Although it is a distinctively marked species, there are some very similar species and care is needed with identification. Length 15-18mm, broad oval shape. Pronotum pale with two transverse da

Agabetes acuductus

Identification: Elytra has dense, short longitudinal scratches (strioles). See Larson or Epler . Some adults may have non-functional flight muscles.

Agabus amnicola

member of uliginosus species-group that also contains the nearctic A. margareti Larson and 5 palæarctic spp.

Agabus antennatus

Identification: Males are most easily identified by the enlarged terminal antennal segments. Colour on both sexes identical- head and pronotum reddish to yellowish brown, elytra darker brown with pale lateral and basal margins. Ventral side of head r

Agabus anthracinus

Identification: mostly black, with lighter (rufous to piceous) legs, frontal spots, palpi, and lateral & basal borders of elytra and pronotum. Antennae pale basally. Elytra sculpture rather coarse, resembling scales. Prosternal process convex to angu

Agabus bipustulatus

9.5-11.5mm. A very common black diving beetle with pale brown antennae and brown front legs. It has a smoothly rounded outline with elongate microsculpture within which is a mesh pattern. Favours still or stagnant water or sluggish bays in running wa

Agabus canadensis

Identification: Shape broadly oval; Head and pronotum dark brown to almost black; elytron paler brown with basal and lateral margins yellow; A pair of reddish spots present on the frons; Sides of pronotum broadly red to reddish brown (width of the re

Agabus clavicornis

Identification: Sexually dimorphic- males with clubbed antennae.

Agabus crassipes

Identification: penultimate labial palpomere enlarged, triangular

Agabus didymus

7.5 to 8.0 mm. Can be identified by its bronze colour and characteristic pale ‘N’ shaped elytral markings. Found in rivers, brooks, streams and canals. Widespread and frequent in the southern half of Britain, but less well recorded further north. No

Disintegrated Diving Beetle

Agabus disintegratus

Identification: Holotype larvæ described in members of this group possess a stridulatory organ

Agabus erytropterus

The original description by Thomas Say in 1825 ( Pdf here p.95 stipulate Colymbetes erytropterus . Fall's publication in 1922, A review of the North American species of Agabus, on page 21, mention this insect as Agabus erythropterus .

Agabus guttatus

Length 8 or 9 mm. A dark brown/black diving beetle usually with pale spots on the elytra. Similar (but usually smaller) spots occur in other species. The elytra are covered in a fine mesh-like reticulated micro-sculpture. A row of fine punctures runs

Agabus nebulosus

A brown, sometimes mottled, medium-sized (7.5 to 8.3 mm) water beetle which may be very similar to Agabus conspersus. Agabus nebulosus differs mainly in having two dark spots on the pronotum which are visible in the field. It is only safe to conclude

Agabus paludosus

Length 6.5-8mm. Shiny brown elytra, dark head and pronotum. Photograph showing diagnostic features required. Widespread and fairly frequent in Britain. No additional images available for this species.

Agabus punctulatus

Identification: oval, small; rather shiny, dark reddish brown to almost black dorsally, often with a greenish sheen in life; lateral margins of pronotum and elytra paler; male protarsal claw with a subapical ventral tooth

Agabus sturmii

This predaceous diving beetle is similar to a number of others and specimens must be examined for a safe identification. No additional images available for this species.

Agabus taeniolatus

Identification: Very similar to A. disintegratus , with overlapping range. Distinguished by entirely reddish venter

Bidessonotus inconspicuus

Identification: B. pulicarius ≤2.0 mm; B. longovalis : elytral plicae distinctly longer than pronotal plicae

Celina angustata

Identification: fine microsculpture on central portion of pronotum, with some punctures distinct Det. Tim R. Moyer, 2010

Celina grossula

Identification: distinguished from the congeners in our area by large size (>6 mm), coarse pronotal punctation, and unmodified male mesotibia Type Locality: Louisiana not listed in

Celina hubbelli

Identification: Adult: body elongate, reddish-yellow to reddish-brown with basal one-fourth of elytra and pronotum paler. Pronotum with punctures large laterally, fine but evident on disc. Elytra coarsely irregularly punctate, each puncture with shor

Celina imitatrix

Identification: elytron with punctation coarse and irregular; pronotum dull with microsculpture meshes large and well impressed, disk with punctation fine and dense, laterally with larger punctures broadly distributed Type Locality: Gainesville, Alac

Clarkhydrus falli

Identification: Robust, ovate; outline of pronotum and elytron continuous Type Locality: Tucson, Ariz.

Clarkhydrus spectabilis

Clarkhydrus spectabilis (Clarkhydrus spectabilis) is a species in the family Dytiscidae, commonly known as predaceous diving beetles, belonging to the order Coleoptera (Beetles). It is classified within the subfamily Hydroporinae, tribe Hydroporini,

Colymbetes dahuricus

Identification: Ventral surface including legs entirely dark Color generally paler dorsally- pronotum rufous with a medial dark spot

Colymbetes densus

Identification: In this species, the frons is swollen (rather protruding) in front of the eyes (comments by Tim Loh here ).

Colymbetes exaratus

Identification: One of the members of the C. sculptilis species complex, which consists of 5-6 similar to identical species; species identification is only reliable from examination of male genitalia (length of adeagus)and in some cases subtle differ

Colymbetes fuscus

A large diving beetle (15-19 mm). Although this may look a dark species, the elytra are light straw brown and on close inspection have a network of black, transverse grooves. The beetle is darker brown underneath. The head and neck shield are also br

Comal Springs Diving Beetle

Comaldessus stygius

Identification: Diagnosis: Comaldessus stygius differs from all known North American bidessine species by the following combination of characters: Type Locality: TEXAS: Comal County, New Braunfels, Landa Park, Comal Spring 3, net near springhead, 10-

Copelatus caelatipennis

Identification: most specimens with base of elytron pale and contrasting with [slightly] darker color of pronotum and [much darker] remainder of elytron

Chevrolat's Dytiscid

Copelatus chevrolati

Identification: Unique pattern of elytral striae Det. B. Mathison, 2010 Readily comes to lights

Copelatus debilis

Identification: Elytron with 5 or 6 discal striae; elytral base distinctly paler than disc in most specimens

Copelatus distinctus

Identification: 10 discal striae and longitudinal strioles on lateral portion of pronotum; many striae are commonly reduced or absent, especially in males

Copelatus glyphicus

Identification: Adult: pale yellowish brown to reddish brown, ventral surface darker. Body with fine, moderately dense punctation dorsally. Pronotum with lateral bead complete. Each elytron with short sulcus near margin plus 10 complete sulci. Venter

Coptotomus longulus

Identification: reliably distinguished by broad metasternal wing (narrowest width between mesocoxa and edge of metacoxal plate) of 0.35 mm or greater

Coptotomus venustus

Identification: Labial and maxillary palpi notched apically; last abdominal sternite without a pair of medial parallel grooves; elytra without dense sculpture of irregular grooves

Desmopachria dispersa

Identification: Body broadly ovate, somewhat depressed; elytra and pronotum rather deeply and densely punctate; metacoxal plates relatively coarsely and densely punctate;

Desmopachria mexicana

Identification: Elytron with lateral dark spots separate from combined discal and sutural markings; pronotum with discal punctation distinctly finer than that of elytra; metacoxal plate relatively coarsely but shallowly punctate

Desmopachria seminola

Identification: Body more narrowly ovate and more convex; elytra and pronotum more finely and less densely punctate; metacoxal plates more finely and more sparsely punctate

Boreal Water Beetle

Dytiscus alaskanus

Identification: Relatively small for the genus; metacoxal lobes acuminate; abdominal sterna yellow with expanded black markings; sulcate (ridged) females with ridges separated by yellow striae, ridges 7 & 10 and 8 & 9 fused apically

Dytiscus circumcinctus

Identification: Large and elongate, sometimes with a greenish sheen; ventral surface mostly yellow without expanded black markings on abdominal sterna (margins of sterna narrowly black); metacoxal lobes acuminate (pointed); inner margins of the eyes

Dytiscus circumflexus

In this species the metacoxal plates are sharply pointed. It is 30 mm or more in length and the pronotum has narrow yellow borders front and back with the sides being only a little wider. Other distinguishing features are the underside of the beetle

Dytiscus cordieri

Identification: Moderate size; pronotum and elytra broadly lined with yellow laterally; ventral surface mostly yellow with few dark markings; hind coxal lobes rounded .

Understriped Diving Beetle

Dytiscus fasciventris

Identification: only the anterior and lateral margins of pronotum are bordered by a broad pale stripe (posterior margin not bordered); lateral margin of elytron bordered by broad pale stripe on basal half only remainder of dorsal surface brown, brown

Great Diving Beetle

Dytiscus marginalis

One of our largest beetles, this species has a dark, olive-brown, almond-shaped oval body, about three centimetres long. The pronotum is completely bordered by a yellow margin - one of the key features that enables this species to be recognised in th

Vertical Diving Beetle

Dytiscus verticalis

Identification: Adult: pronotum with yellow border on lateral margins only; yellow lateral margin of elytra continues as an oblique line across apex; two tibial spurs on hindleg are approximately equal in size North Carolina State U. has 7 specimens

Ereboporus naturaconservatus

three specimens collected in drift nets (300–500 µm) over two spring orifices of Caroline Springs, the headwaters of Independence Creek, Terrell County, Texas.

Eretes explicitus

Type Locality: Balmorhea State Park, Texas, VII-7-1963, P.J. Spangler

Graphoderus occidentalis

Identification: Diagnostic characters include: posterior black fascia of pronotum contiguous with hind margin and anterior black fascia of pronotum contiguous with anterior margin. The male mesotarsus is also not dilated (widened) in this species.

Graphoderus perplexus

Identification: Unlike G. occidentalis , the posterior black fascia on the pronotum (the black band at the bottom part of the pronotum) does not reach the hind margin. The black band is contiguous (unseparated) with the hind margin in G. occidentalis

Haideoporus texanus

Type Locality: Artesian well at the Aquatic Station, Texas State University, San Marcos, Hays County, Texas. Texas considers this a "Species of Greatest Conservation Need" (SGCN) This is the 1st blind, depigmented, aquifer-adapted Dytiscidae describe

Hornectes quadrimaculatus

Identification: color pattern distinctive ▪ Syntype

Hydaticus aruspex

Identification: body and frons black, yellow-reddish spots on frons, elytra with sharply delimited yellow margins (Larson et al. 2001) ( H. piceus is brownish, with frons brown-rufous and no yellow lateral margins on the elytra)

Hydaticus cinctipennis

Identification: characterized by brown body, rufous to brownish frons, and sharp yellow margins on the elytra (in H. piceus paler margins fade away)

Hydaticus piceus

Identification: Very similar in terms of body and frons colouration to H. cinctipennis but lacks the sharply defined yellow margin on the elytron seen in the latter species.

Hydrocolus paugus

Hydrocolus paugus (Hydrocolus paugus) is a species in the family Dytiscidae, commonly known as predaceous diving beetles, belonging to the order Coleoptera (Beetles). It is classified within the subfamily Hydroporinae, tribe Hydroporini, suborder Ade

Hydrodytes dodgei

Identification: resembles a diminutive Copelatus , distinguished by smaller size and lack of elytral and sternal striae

Hydroporus angustatus

A small (approx 3 mm) mid to dark brown water beetle. No additional images available for this species.

Hydroporus discretus

This is a small dark greeny black water beetle with orange brown legs and antennae. Widespread and fairly frequent in Britain. No additional images available for this species.

Hydroporus gossei

Identification: Similar to H. rectus, but more oval in shape, apexes of labial palps usually infuscated, and has coarser punctation.

Hydroporus incognitus

A small (3 to 3.5 mm) dark brownish water beetle with paler creamy orange coloured markings which vary from one specimen to another. In still water such as ponds and in slow moving water. No additional images available for this species.

Hydroporus memnonius

Length 3.8 to 4.3 mm. Sides more or less parallel. Colour may vary from rufous to almost black. Aedeagus with distinctive tongue-like process. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a mi

Hydroporus palustris

3.3 to 4.0 mm. Elongate oval; the elytral outline is smoothly curved from base to apex. Dark elytra with yellow patterning at the front and sides, though this can be variable. Head red at the front. Antennal segments darkened along the apical half. U

Hydroporus planus

3.8 to 4.8 mm. Black head and pronotum with dark red/brown elytra. The front corners of the elytra are a paler grey. It is generally covered in long, pale hairs. Hydroporus species are generally very hard to separate but the size, black head, grey fr

Hydroporus rectus

Identification: See Larson et al. for a detailed description.

Hydroporus sinuatipes

Identification: Relatively large species; protibia with ventral margin distinctly emarginate sub-basally, especially in the males • Holotype

Hydroporus tessellatus

Length 3.4-3.8mm. Whole of head and pronotum black. Elytra streaked and mottled, aedeagus blunt. No additional images available for this species.

Hygrotus inaequalis

This is a small (3 mm) water beetle. The dark brown elytra are marked with paler yellowish buff. In the water of well vegetated ponds and ditches.

Hygrotus lutescens

Identification: The only reliable character separating H. lutescens and H. sellatus is the sculpture of female abdominal sterna

Hygrotus marklini

Identification: A rather uniformly coloured Hygrotus- dorsally brown to piceous (Very dark reddish brown) in colour, ventrally mainly black; head dark with an isolated pale spot on the frons; pronotum pale yellow brown anteriorly, darkened posteriorl

Hygrotus nigrolineatus

Length ~4mm. Distinctive body pattern of dark longitudinal lines. Pronotum predominantly pale yellow but typically with a dark patch or smudge in the middle. First recorded in the UK on 1983. Unless identified by a recognised expert, a photo is requi

Hygrotus sellatus

Identification: Species can be easily identified from the distinctive patterning of the elytra- there is distal brown blotch and a subhumeral spot on a pale background, the sutural margin is also dark; pronotum is dark, with paler anterolateral borde

Hygrotus wardii

The only species of Hygrotus with its primary distribution in Mexico

Hyphydrus ovatus

Length around 4.5 mm. The small oval/globular form and dark red to brown colouration are distinctive. Some have vague elytral patterning at the margins, especially in teneral specimens. Hyphydrus aubei is a similar size and shape but has a much more

Ilybiosoma bjorkmanae

Identification: Color dark brown to black Pronotum constricted at the base, discontinuous in outline with the elytra.

Ilybius ater

A fairly large smooth blackish water beetle. Always associated with aquatic environments, but flies well and can be attracted to light. The typical habitat is emergent vegetation in shallow water at the edge of ponds, lakes ditches etc. All year roun

Ilybius discors

Identification: lectotype Externally similar to I. austrodiscors Larson, a n.CA endemic

Ilybius fenestratus

Length approx. 11 mm. This species has dark colouration and a broad-oval shape which is widest behind the middle. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box

Ilybius fuliginosus

A 10 to 12 mm long dark brown bronze diving beetle with pale yellow stripes along the margins of the elytra. Permanent water which is vegetated, including rivers, canals, drainage ditches, ponds and lakes. It flies well and may be attracted to light.

Ilybius subaeneus

This family of water beetles is related to the ground beetles, but are much modified for life in water. Adults and larvae are fiercely carnivorous. Fairly frequent and widespread in much of Britain except the extreme north. No additional images avail

Ilybius wasastjernae

Ilybius wasastjernae (Ilybius wasastjernae) is a species in the family Dytiscidae, commonly known as predaceous diving beetles, belonging to the order Coleoptera (Beetles). It is classified within the subfamily Agabinae, tribe Agabini, suborder Adeph

Laccophilus maculosus

Identification: Relatively large compared to other members of the genus; overall brownish in colour with elytra irrorate (freckled); the density of freckling varied, with the greatest around pale spots located along lateral, basal, and sutural margin

Laccophilus minutus

Length about 4.5 mm. A small green/brown diving beetle, the elytra can be dark but may have varied paler markings. Mainly found in ponds and pools but has occasionally been recorded from flowing water. Has been recorded in most months of the year. Wi

Laccophilus proximus

Identification: Elytral iorrations (freckling) more even in density without significant darkening around the pale sublateral spots. Most similar to L. maculosus but in maculosus , the pale spots are outlined/surrounded by denser, darker freckling; al

Laccornis conoideus

Identification: Antenna with outer antennomeres infuscate apically (show some degree of darkening); colour as described by Larson-reddish brown overall, head brown with reddish areas anteriorly, ventrally, pronotum dark brown with some red laterally,

Leconectes striatellus

Identification: Each elytron with at least a sutural stria and several discal striae; dorsum densely punctate, with punctures bearing yellowish to brown hairs/setae. Colouration from almost uniformly black to vittate.

Liodessus flavicollis

Identification: most distinct coloration of Liodessus with submedial and apical transverse pale fasciae

Liodessus obscurellus

Identification: Reliably separated from L. affinis by aedeagus only comes in numbers to lights

Meridiorhantus calidus

Identification: Pronotum dark medially with broad pale lateral margins; elytron variegated; ventral surface dark reddish brown ( 3 ) Adult's head dark brown to black, large eyes, front and top of head with brownish-yellow spot. Elytra with pale band

Nartus sinuatus

Identification: Black with dark rufous legs; posterior margin of pronotum arched just before hind angles ( 3 ) An uncommonly seen/collected species, most likely due to habitat inaccessibility.

Neobidessus youngi

Identification: The modified hind trochanters are distinctive. Otherwise, a lightly marked species similar to N. pulloides .

Neoporus arizonicus

Identification: possibly same species as N. dimidiatus

Neoporus pratus

Identification: iNaturalist Type Locality: Kansas, Douglas Co., Grant township, Scorpion Hill

Neoporus uniformis

Identification: Similar to N. lobatus , and possibly a southern form of this species. "Lighter in color, more coarsely punctate, and more shining and smaller than typical N. lobatus ."

Neoscutopterus hornii

Identification: Antennae and palpi entirely pale, with little or no darkening; metasternal wing narrow

Oreodytes scitulus

Identification: Epipleuron does not meet the humeral angle between pronotum and elytron (visible in the lateral view). Distinctive colour pattern on pronotum and elytra: with anterior and posterior black markings on the pronotum that are joined/conti

Psychopomporus felipi

Species description based on two specimens and three large fragments of additional specimens collected from two springs that discharge into the western side of San Felipe Creek in Del Rio, Val Verde County, Texas, USA (29.37234°N, 100.88602°W). Texas