Water Boatmen (Corixidae) - 109 Species, Identification & Facts

Callicorixa praeusta

7-8mm. This species is similar to several other species of water boatman and detailed examination is necessary for a sound id. As with other species it has a gold and black wave pattern on the pronotum and elytra. Both sexes have a black 'square' at

Corixa dentipes

The species is similar in size (12 to 15 mm.) and appearance to the more common Corixa punctata . C. dentipes is easily distinguished from other Corixa species by the indentation or notch in the tibia of the middle leg, where it joins the femur. Unle

Corixa panzeri

Corixa panzeri is 10 to 11 mm in length and has 10 to14 pale lines on the pronotum. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method u

Corixa punctata

12-15 mm. There are 15-20 lines on the pronotum. The dorsal surface is not keeled on this species and the middle and back legs are more or less the same length. The strigil of the male (on the left under the wings) has 9-10 ridges. Corixa dentipes is

Cymatia bonsdorffii

Length 6-6.5mm. Pronotum uniform colour (no stripes), eyes protruding, wings transversely patterned, pronotum length ≈ head length. Detailed photos and measurements required. No additional images available for this species.

Cymatia coleoptrata

3.4-4mm. One of the few Corixidae that can usually be identified from an image. It is usually brownish in colour with large eyes and a yellow face. It is the only corixid with pale and dark longitudinal lines. The pronotum is smaller than the head. W

Cymatia rogenhoferi

About 7.5 mm, and lacks lines on the pronotum and also transverse wrinkles on the rostrum. It has pale yellow patches at the top of the corium. There are three Cymatia species in the UK. The genus is characterised by the lack of lines on the pronotum

Hesperocorixa linnaei

7 to 8 mm. Six pale lines on the pronotum and the pattern of light lines on a dark background extending to the posterior apex of the corium. Please measure length and record dorsal patterning as described. Good quality photographs of dorsal and ventr

Hesperocorixa moesta

Length 5.2 mm. Mid legs with shorter claws, ≤ tarsus-length. Abdominal segment 7 upperside with middle of hind margin convex & bearing tuft of long hairs. Strigil broad, 6 combs. Photographs showing the key identification features required. In detrit

Hesperocorixa sahlbergi

7 to 8 mm with seven to nine pale lines on the pronotum. The pattern of light lines on a dark background fades to a pale patch near the apex of the corium. Unless identified by a recognised expert, photos of the dorsal and ventral surfaces are requir

Micronecta scholtzi

Micronecta scholtzi is a species of lesser water boatman. With a length of 2 to 2.5 mm Micronecta scholtzi is generally larger than the other species of Mirconecta and has a distinctive pattern of brown markings on the vertex, sometimes described as

Paracorixa concinna

Length 7 to 8 mm. Hind tarsus with small dark mark at apex of inner edge, opposite similar mark on base of claw; corium sharply wrinkled longitudinally, light dorsal markings fragmented. Good photographs showing key identifying features required. Fou

Sigara distincta

8-9mm. One of several very similar Corixidae species of water boatmen. Detailed examination is necessary for identification of species. Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscop

Sigara dorsalis

7.3mm, 6 pales lines on the pronotum. The lines on the hemielytra are more broken with yellow yellow patches at the top. Hesperocorixa linnaei is a similar size and also has 6 pale lines on pronotum - to distinguish check xiphus or male pala. Usually

Sigara falleni

One of the larger Sigara species (length 7 to 8 mm) with 7 or more pale lines on the pronotum. This is one of several very similar small water bugs. Detailed examination is needed to identify the species. Good quality photographs of dorsal and ventra

Sigara fossarum

Length = 6.1mm. 5-6 pale transverse lines on the thorax. There is a dark patch near inner angle of the corium and in middle of clavus. Male palae have base and upper margin relatively square and the pegs form a diagonal line to reach the upper margin

Sigara iactans

Very similar to Sigara falleni , can only be distinguished by male pala. Sparsely vegetated ponds with little organic matter. First recorded in the UK in Norfolk in 2005 but seems to be rapidly spreading west.

Sigara lateralis

5-6.5mm, the only species of the genus to have an entirely dark posterior claw. This is one of several very similar small water bugs. It has a pattern resembling a gold coloured wave effect on the elytra. Detailed examination is needed to identify th

Sigara limitata

Length = 5.8mm. Lateral angle of pronotum symmetrically rounded. Hair fringe on tarsus light brown. Male facial depression deep, reaching top of ‘face’, upper margin strongly rounded, ends at a transverse keel level with the bottom of the eyes. Male

Sigara nigrolineata

A smaller species, length 5–6.5mm, with 7-9 pale lines on the pronotum, a pala with a single row of pegs and a more or less triangular xiphus. The male of S. nigrolineata has a facial depression below a transverse keel (or ridge) that is level with t

Trichocorixa verticalis

inadvertently introduced to Europe (Portugal) ca. 2000, maybe with mosquitofish ( Gambusia sp.) --a rare example of such spread among aquatic bugs ; spread to Spain & N Africa