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Section J

Most of the beetles here are from (unless otherwise stated) the group Cantharidae, known as the Soldier beetles. I've listed a few of the more common ones and a brief pictorial guide (with the aid of Cantharid queen Steph Skipp) to the often less-covered smaller species. 

She would love it if you can send her any records via iRecord

There are many similar species and for the larger, brightly coloured species there are some excellent free guides already available.


If you like pictures try Mark Gurneys picture guide

If you like something a bit less colourful then Kieth Alexander & Martin Harveys field guide is HERE

For a key to all of the UK's species, there's also The Fitton Key


Cantharis decepiens 

A very common species found throughout Britain in a range of habitats


ID Features

7.5-8.5 mm

sandy tan colour

Pronotum tan with dark 'Phallus' shaped marking

black head 

Shiny tan elytra completely covering wings  covered in short hairs


Rhagonycha fulva

Often occur in large numbers towards the end of the summer, known as 'blood sucker' or 'bonking beetles'.

Despite frequently being seen 'bonking' they have never been documented sucking blood and instead feed on pollen and smaller insects.


ID Features

8- 10 mm

sandy tanelytra with black tips

red and black legs 

red head 

steve french rhagfulv.jpg

S. French

Rhag fulv
canth rust.png

Cantharis rustica 

Probably the most frequently encountered large species of soldier beetle in the UK


ID Features

9.0 - 13.0 mm

Black wing cases

Black legs with red (femora) bases

Red pronotum with central heart-shaped dark mark

Canth rustica

Malthodes/ Malthinus

Small (under 5mm) black and yellow soldier beetles, often beaten from deciduous trees but occasionally turn up in moth traps.

They usually have black elytra with distinctive yellow tips They can be a bit of a pain to separate, but if you can separate the 2 Genera, you are already halfway there.

It is possible to split the 4 Malthinus species fairly simply (see below guide) however Malthodes are another kettle of fish and may require genitalia dissection.

For a key to all of the UK s soldier beetles, including genitalia diagrams

Try here 


Malthodes flaveolus

Splitting the Two


Malthinus sp. 

More boggle 'eyed' 

roughly triangular head


mandibles with a tooth

Bell shaped pronotum

Head and/or pronotum more course with rough punctures 

Pale legs

Malthodes sp.

Less boggle-eyed in comparison (although some males do buck this trend)

rounder head 


mandibles without a tooth

A more square-shaped pronotum

Head and/or pronotum smooth, at most finely punctured

Darker legs

Malthinus- 4 species 

Cantharid whizz, Steph Skipp showed me the easiest way, by far, to split the 4 British species was through pronotum patterns.

Be aware that often these markings can merge (in the case M. flaveolus particularly) and can be pretty variable, but its a great way to begin to split them, when used in conjunction with other ID characteristics 



M. seriepunctatus


Pronotum patterns in UK Malthinus species 


M. flaveolus 


M. balteatus


M. frontalis


ID Features

Punctures in rows 

Pronotum with Black' hourglass marking 

Scutellum with at least apex yellow


ID Features

random punctures

Pronotum with  2 lines, may merge to form a 'V' shape  


ID Features

Pronotum with thick vertical band with parallel sides 

Scutellum entirely 'dingy brown' (fuscous)

Elytra have a horizontal(transverse) white line across it 


ID Features

Entirely black pronotum ​



M. seriepunctatus


M. flaveolus 


M. balteatus


M. frontalis

Malthodes- 12 species 

Of the 12 Uk species, I feel only one ID easilly recognisable in the field IF it is a typical example.

Personally  I would recommend keying any other suspect Malthodes out properly.

Be aware there are completely dark forms that do occur and that they can be incredibly variable.

Malthodes marginatus



ID Features (of a typical specimen)

Pronotum with a lateral border when viewed dorsally (left)

Pronotum with all 4 corners  paler​, often forming a 'blurred' cross shape

Male with bulbous eyes and abnormally long antennae 

Male (Left) & Female (Right) Malthodes marginalis)

Malthodes mar

The odd ones out 

These beetles are not soldier beetles, (Cantharidae) and simply superfiscially resemble them, for ease of identification I have put them here.

Malachius bipustulatus




ID Features

approx 5.5-6.0 mm

metallic green body and legs 

2 pink, well defined spots on elytra ends

Transverse pronotum (Wider than long)

Second antennomere strongly serrate


Only likely to be confused with the smaller Cordylepherus viridis which has smaller spots on the elytral ends, is overall smaller (4.0-5.5mm), quadrate pronotum (as long as wide) and with a less serrated second antennomere.

The Malachite beetle, incredibly common throughout the spring and summer months 

image via: Wikicommons

Malachi bi
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