Section A
Affectionately known as Carabids, these beetles are hailed as ‘a beginner group’ as a result there are lots of marvelous in depth ID guides for in-depth identification.
This group is characterised by long thread-like antennae (filiform), generally having a smooth flattened wing case (elytra) and tending to have a ‘generalised beetle shape’. Most species found in traps tend to possess the ability of flight, although some species have fused wing cases and lack this ability. Despite this due to their free-roaming inquisitive nature will still find themselves in a moth trap from time to time.
Loricera pillicornis
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ID Features
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Metallic black or brown
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Pronotum edges with strong, even curve
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6 very obvious ‘dents’ in the elytra (2 rows of 3)
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Antennae with very long protruding hairs
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6-8mm
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Pronotum edges with strong, even curve
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April – September
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Widespread in woodland, gardens and near water
Pterostichus madidus
A large, generic-looking beetle, is probably one of the most common species in the UK. This one has 2 colour forms, one with red legs and one with black legs.
There are 19, very similar species. They have a fairly elongated, yet chunky-looking head and flared-out front legs (tibiae).
John Walters has done a very good key for them here.
ID Features
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Rounded hind angles of pronotum
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Red or black legs
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14mm
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Single puncture on 3rd elytral interval
Note: This species of Pterostichus is very easy to ID from a decent dorsal view, however similar species may need dissection or an in focus underneath shot to look for pubescence (a light coating of hair).
Taking Photos
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Rounded pronotal hind angles
(with no tooth or sharp edge) of P.madidus
Bradycellus sp.
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Small brown to black beetles, Usually appearing in large numbers. There are 7 UK species but B. verbasci and B. harpalinus both come to light.
It is possible to split the two with differences in pronotum shape, however, they can be slight and this doesn’t rule out any other species that may occur.
Dissection of the male reproductive organs (Adeagus) is strongly recommended for 100% certainty.
B.harpalinus is incredibly variable in colour, so dissection and examination is recommended.
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For genitalia diagrams I recommend page 26 onwards of Mike Hackstons key.
ID Features
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Bradycellus verbasci
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Pale brown to dark black
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Tends to have more ‘wobbly edge’ to strong pronotal hind angles
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4.0-5.5mm
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Jan– Dec
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Widespread​
Bradycellus harpalinus
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Pale brown to dark black
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Tends to have more evenly curved pronotal hind angles
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3.8-5mm
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Jan-Dec
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Widespread
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Harpalus rufipes
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ID Features
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Large beetle 11.0-16.0mm
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Black body
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Red legs
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A golden sheen of hairs on wing cases (you have to catch this in the right light to really appreciate it)
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Sharp pronotal hind angles
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Abdominal sternites with pubescence
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Mar-Nov
Image: Ryszard CC BY NC 2.0
Image: Donald Hobern CC BY 2.0
Harpalus griseus
Watch out for smaller-looking specimens, which may actually be the recently introduce Harpalus griseus which is separated by a less sinuate side to the base of the pronotum and has a stripe of pubescence down the center of the abdominal tergites (Whereas H. rufipes has pubescence only at the sides).
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Probably one of the most common large beetle species found in moth traps mid to late summer, their large size, red legs, and a golden sheen to the wing cases caused by their hairs are their main tell.
Chlaenius vestitus
There are 3 other species of Chlaenius in the UK but the all lack the sandy yellow elytral apex and sides of vestitus.
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All of the UK Chlaenius are associated with wetland areas.
ID Features
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Bright green, medium sized beetle, often with a golden tint (pictured)
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Sharp pronotal hind angles
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April—August
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9-11mm
Cychrus caraboides
ID Features
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Large elongate beetle with a large booty
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Long face with protruding mandibles
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Long legs
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Matt black, granulated elytra
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14-19mm
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June– Nov
A common ground beetle I usually encounter during early spring and Autumn under logs or in leaf litter.
They specialise in hunting snails, which is why they have a long head to poke into the shells of their prey.
Image: Ryszard CC BY NC 2.0
Carabus violaceus/ problematicus
Two very similar species both appropriately referred to as ‘violet ground beetles’. Both are large, leggy species that actively hunt at night.
The differences between them are subtle and incredible comparative but are outlined incredibly well here
Carabus violaceus
ID Features
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20-30 mm
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Black with purple metallic edges
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Elytra with shorter, irregular granules (Right)
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Less elongate compaired to C. problematicus
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In woodlands and grasslands
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August—Sept
Carabus problematicus
ID Features
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20-28mm
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Black with purple metallic edges
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Elytra with long granules, almost giving a striped appearance (Right)
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More elongate when compared to C.violaceus
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May– Aug
Image: Udo Schmidt CC BY SA 2.0
Image: Udo Schmidt CC BY SA 2.0
Image: Vlad Proklov CC BY NC 2.0
Image: Frank Vassen CC BY 2.0
Panagaeus cruxmajor
An incredibly rare, yet obvious beetle, that famously caused Charles Darwin some grief when collecting.
There are two species of Pangagaeus in the UK, however the other
(P. bipustulatus) has a pronotum that is as wide as long (quadrate) , is associated with dry sandy/gravelly soils, is on average smaller (6.5-7.5mm) and has 2 different puncture sizes on the pronotum
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ID Features
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7.4-8.8mm
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pronotum wider that long (transverse) with rounded sides
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small head in comparison to the body and pronotum
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Antennae long and thread like (filliform)
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black head and pronotum
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Elytra with 4 clear, square, orange markings
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Pronotum with punctures of one size
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March - April, August, October
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On soft soils near fresh water
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VERY RARE- please iRecord
Ophonus sp.
ID Features
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heavily punctured pronotum
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extensively pin pricked appearance to elytra
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Fine hairs on pronotum and elytra
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One long hair (setae) over each eye
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Black, reddish brown or metallic blue
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If its large (10-14mm) with a blue sheen and red legs (pictured left) it is likely to be Ophonus ardosiacus
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The smaller redder species commonly found at light are O. rufibarbis and O. puncticeps although
O. melletii has also been found in moth traps. For the smaller species microscopic examination is required for an accurate identification.
There are several similar species of Ophonus in the UK, most feed on seed heads of unbeliefers and are typically encountered mid to late summer, they look similiar to the closely related Harpalus species but differ by being punctured extensively on the pronotum and elytra.
Dyschirius sp.
Family: Carabidae
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11 British species , with only 7 found in Ireland (Luff 2007) . Small beetles with an obvious pinched in waist that look superficially like Clivina spp.(which can be separated by continuous obvious punctures around the edge of the elytra and a complete border on the edge of the pronotum).
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These are associated with burrows of other species and are actually fossorial in nature, so will likely be a fairly uncommon visitor to moth traps.
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ID Features
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Dark brown to brassy black
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Pronged front tibae
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Obvious thin waist
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Almost spherical pronotum
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3.1-4.9 mm
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May - July
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The odd one out
Family: Tenebrionidae
This cheeky little beetle always tricks people into thinking it's one of the Carabidae (ground beetles), with a similar body shape and antennal features. I usually find it on drier sites but is a very active beetle at night.
ID Features
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average 12mm
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evenly rounded body
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Dull brown to reddish, almost purple black
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evenly punctured elytra in clear rows (stria)
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Trochanter less than a third of the femora
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Have enlarged genae cutting into the front margin of the eye
(see below)
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Nalassus Laevoconstriatus
Tenebrionidae - it's all in the cheeks
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Tenebrionidae are very varied in appearance and it can be a pain to separate them from very similar-looking beetles. In most instances, they can be split by looking at the Gena, effectively the cheeks of the beetle. In Tenebrionidae the gena protrude across the front of the eye, giving them almost cartoon-like cheek features. It certainly works for splitting Nalassus from other UK Carabidae.
Typical Tenebrionid head showing expanded genae marked in red via: Wikicommons
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