Task 7

Carabidae

For this task I was asked to curate a mini-collection of Carabidae (ground-beetles). I was provided with a container of 10 numbered specimens that were pinned/glued to card.

I was provided with a key: "The Carabidae (Ground Beetles) of Britain and Ireland" (Luff, 2011) for use in identifying the specimens.

Each specimen was identified using the key and microscopes provided by Oxford Brookes University.

Photographs were taken and the steps taken in the key to identify each specimen are shown below.

In a collection each specimen will have a number of labels providing information. These will typically be:

Identification/Determination ('Det') label:

Containing the Species, who determined it and the year of determination.

Specimen number label:

The specimen number of the collection.

Locality label(s):

Date and place of collection, who collected the specimen, the habitat and other collection details.

An example, for specimen 1, is shown on the right, with the location taken from a real example from NBN atlas (National Biodiversity Network Trust (NBN Trust), 2023):

Identification/Determination ('Det') label:

Carabus nemoralis Müller, 1764

Adam Ixer, 2023

Locality label (1):

30 Oct 2023, Adam Ixer

Foxcote Wood, 52.025, -0.963

Specimen number label:

1

Locality label (2):

Woodland, pitfall nr. beech

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 -> 2 -> 3 -> 4 -> Carabini p.38

1 -> hind angles backwards, so Carabus Linnaeus p.39

1 -> 3 -> 5? -> 7 -> 8 -> Elytra with … 3 rows of fine punctures

= Carabus nemoralis Müller

Specimen 1

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 -> 2 -> 6 -> 7 -> 9 -> 10? (unsure) -> 11 -> 13 -> 14 -> 24 -> 25 -> 26 -? Lebrini (didn’t think so)

Went back and restarted at step 14 -> 15 -> 16 -> 17 -> 18 -> 19 -> Sphodrini + Platynini p.116

1 -> p.122 Sphodrus leucophthalmus (Linnaeus) NO, checked with Darren Mann, Collections Manager at Oxford University Museum of Natural History (OUMNH),  and this was incorrect.

Went back and started at step 19 -> p.105 Pterostichini tribe

1 -> 2 -> 3 -> p.107 Pterostichus Bonelli

1 Hind angles sharp? -> 4 Scutellary stria well developed -> 6 Length more than 8mm -> 7 No setae beneath tarsi -> 9 Length more than 15mm

= Pterostichus niger  Schaller

Specimen 2

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 Short setae -> 2 Looks like fig. 15 -> 6 Eyes normal -> 7 Scutellum not on waist -> 9 Feature not present on the specimen! -> 10 No frontal furrows-> 11 No puncture -> 13 Mandibles not truncate -> 14 Gradually rounded, sinuate -> 15 2 setiferous punctures behind eye -> 16 Not these features -> 17 Not these features -> 18 Labial palp broken but does not look to have any setae? -> 19 Elytral margin is simple -> Sphodrini and Platynini p116

1 Less than 18mm -> 2 Tarsi not pubescent -> 3 Claws smooth -> 5 Fovea indistinct? x -> 6 Doesn’t look like any of these plates! NO, so, back to step 5

5 Doesn’t look like plate 88! NO

So, back to step 18 (on p37)

18 Labial palpi with 3 or more setae? Can’t see but check Zabrini p133

1 2 setiferous punctures -> 2 No sinuate -> Amara Bonelli p134

1 Apical spur with 3 teeth -> Zezea Csiki p135

1 Less than 8mm (hard to tell exact length!)

Check the description: Femora and most of tarsi black, tibiae red/light brown. Antennae black, 3 basal segments clear red. Elytral striae hardly punctured. Widespread, v abundant.

= Amara plebeja Gyllenhal

Specimen 5

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 Short pubescence -> 2 Single spur -> 6 Eyes normal -> 7 Scutellum in line, forming wedge (fig. 23) -> 9 Segment not shorter than penultimate -> 10 No furrows -> 11 No setiferous puncture on mandible? Hard to tell due to glue! -> 13 Mandibles not notched -> 14 Apex gradually rounded -> 15 2 setiferous punctures behind eyes -> 16 Not these features -> 17 Not these features -> 18 Can’t see setae on palpi. Doesn’t look like Zabrini, so go to 19 -> 19 Elytral margin simple -> Sphodrini and Platynini p116

1 Length less than 15 mm -> 2 Tarsi not pubescent above -> 3 Claws smooth -> 5 Pronotum not rectangular -> 6 Sides of pronotum sinuate, sharp hind angles -> 7 3rd antennal segment not pubescent, pronotum black -> 8 Not entirely dark -> 9 Head black, darker than pronotum (just!) and elytra. Apex of antennae darker than base -> Oxypselaphus Chaudoi p124

= Oxypselaphus obscurus (Herbst)

Specimen 9

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 Antennae with short pubescence -> 2 Notched/incision -> 6 Eyes normal -> 7 Scutellum on waist or peduncle -> 8 Front legs fossorial, with strong internal teeth -> Scaritini p57

1 Elytral interval punctured? -> Clivina Latreille p57

1 Unicolorous dark brown

= Clivina fossor Linnaeus

Specimen 10

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Not as described -> Carabinae p.33

1 Short pubescence -> 2 Single spur? Flat incision (hard to see because of glue!) -> 6 Eyes normal -> 7 Scutellum forming wedge -> 9 Apical segment not shorter than penultimate segment -> 10 No furrows? Looks to be next to eye, not all the way around? -> 11 No puncture on mandible? -> At this point, I noticed that on the palps the apical segment was much narrower than the penultimate one, so go back to step 9!

9 Apical segment narrower/shorter than penultimate segment -> Bembidini p69

1 Only has 2 pale spots but more diffuse, so go to 3 -> 3 Head not punctured -> 6 Sides of pronotum rounded, hind angles not protruding -> 7 Hind margin straight? Elytra with heel from 5th stria -> Phyla Motschulsky p99. Checked and doesn’t look to be this!

Try 7 again… -> 7 Hind margin is sinuate -> Philochthus Stephens p100

1 7th stria missing -> 2 Legs pale brown -> 3 Strongly protruding? -> 4 At most 4mm. Check description: Subapical spot present, legs brown, strongly rounded prenatal sides, elytra with 7 strongly punctured striae which fade out apically.

= Bembidion lunulatum Geoffroy in Fourcroy

Specimen 16

Unfortunately this is INCORRECT. At the time I noted that there were a few from the Philochthus subgenus it could have been but I felt the above description matched it best. The 7th stria should have row of distinct punctures, so it is actually:

Bembidion biguttatum Fabricius

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Colour not as described -> Carabinae p.33

1 Short pubescence -> 2 Can’t see feature as it’s glued to the card! Probably not 2 spurs, so go to 6 -> 6 Eyes very large. Together wider than frons -> Elaphrini (p54)

1 Elytra with irregular sculpturing -> Elaphrus (p54)

1 Think it is less than 7.5mm. Think it has a single mirror?. After checking other candidates in Elaphrus:

NOT cupreus as tibiae are same colour

NOT lapponicus as appendages are not black

NOT uliginosus as appendages are not black with green reflection, also very scarce

= Elaphrus riparius Linnaeus

Unfortunately, this was INCORRECT. It is actually:

= Asaphidion flavipes Linnaeus

Specimen 20

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Colour not as described -> Carabinae p.33

1 Antennae look long but not twice as long – also does not look like the plate for Loricerini -> 2 Tibiae with sub-apical notch -> 6 Front tibiae with sub-apical notch, eyes normal -> 7 Scutellum not on a waist -> 9 Doesn’t look to have narrower apical segment of palpi? Hard to see because of glue! -> 10 No furrow -> 11 Can’t see any setiferous puncture? But the length is < 10mm… -> 13 Mandibles sharp, not notched -> 14 Elytra gradually rounded -> 15 2 setiferous punctures?? -> 16 Not these features -> 17 Not these features -> 18 Penultimate segment of labial palpi -> can’t see these because of glue! Doesn’t look like a Zabrini though. So, pick 2 or fewer setae and go to 19 -> 19 More parallel sided tibia, simple elytral margin -> Sphodrini and Platynini p116

1 Length less than 18mm (is about 5mm) -> 2 Tarsi not pubescent above -> 3 Claws smooth -> 5 Rectangular pronotum? Linear, sharp fovea? -> After checking and discarding the other options -> Platyderus p118

After checking description:

Lenth 6-8.5mm (is measured approx. 5mm), body reddish-brown, appendages pale red-brown (although look yellow-brown?). Transverse basal border of elytra extending inwards to meet scutellum, striae not punctured, hind angles rounded and distinct. Therefore:

= Platyderus depressus Audinet-Serville

Specimen 23

Unfortunately this is INCORRECT, it is actually:

= Bradycellus harpalinus Audinet-Serville

Identification

(steps in key / notes):

1 Visible -> 2 Antenna lateral -> 3 Colour not as described -> Carabinae p.33

1 Antennae setae shorter -> 2 Tibia with notch/incision -> 6 Eyes normal size -> 7 Scutellum forming a wedge between elytral bases -> 9 Narrows to a point but not obviously a separate, shorter narrower segment. So go to 10? -> 10 No furrows, stria simple -> 11 setiferous puncture on mandible, <10mm? (is approx.. 5mm) -> Doesn’t look like Pogonini or Patrobini, so go back to 11

11 without setiferous puncture on mandible -> 13 Apex of mandible not truncate (not notched) -> 14 Apex of elytra gradually rounded -> 15 Looks like 1 setiferous puncture? -> 20 3rd antennal segment less pubescence than 4 -> 22 8th elytral stria simple -> 23 Dorsal surface unpunctured and glabrous -> Zabrini p 133 – NO, not the same shape as those shown in plates for Zabrini

So, go back to step 15

15 2 setiferous punctures? -> 16 Not these features -> 17 Not these features -> 18 cant see, but not Zabrini so go to 19 -> 19 Elytral margin simple, apex of tibia more parallel sided -> Sphodrini and Platynini p 116

1 Length <18mm -> 2 Tarsi not pubescent above? -> 2 Claws smooth -> 5 Fovea indistinct? -> 6 Pronotum sides not sinuate -> 10 Non-foveate punctures -> 11 cant see mentam as glued! BUT it is uniform reddish-bronze, pale yellow legs, pronotum almost as wide as elytra, strongly rounded sides and hind angles not really evident -> Olisthopus p123

Description: body reddish brown-bronze reflection, antennae segments 4-11 darker (it is, just?) Yellow appendages BUT tarsi not darkened!

= Olisthopus rotundatus Paykull ?

Specimen 29

Unfortunately this is INCORRECT. It is actually the same as specimen 23:

= Bradycellus harpalinus Audinet-Serville

Identification

(steps in key / notes):

Initial thoughts on viewing the specimen was that looks like a ‘devil’s coach-horse’ / ‘devil’s coach-man’ (which is a rove beetle).

So, using ‘Family Staphylinidae key to UK subfamilies’ (Hackston, 2019):

This states that if over 10mm then it is probably in subfamily Staphylininae -> 11 Antennae further from each other, elytra meet but don’t over-lap.

So, using the ‘Key to the British genera of subfamily Staphylininae’ (Hackston, 2022) :

1. Hind tarsi with elongated 1st segment, antennae closer to eyes than each other -> tribe: Staphylinini

1 Sides of pronotum visible in side view -> 8 Over 9mm long -> 16 punctured and hairy -> 17 Antennae longer and more slender -> 18 Front angles rounded -> 19 Head oval/rounded 4 sides? -> 20 Head and pronotum hairy, background colour black -> 21 Abdomen without yellow hairs on sides, so:

genera = Ocypus and Tasgius, but no key to get any further. Turns out I was correct in my first thought and this was in fact:

= Ocypus olens Müller

Specimen A1

Grouping

How to organise?

Part of curation is ensuring specimens are arranged and organised in a sensible manner. For the specimens selected here I have ordered them in alphabetical order of Family/Sub-Family/Tribe/Genus and grouped them in Tribes.

Justification

A defence of the statement:

"Carabids are potentially an important faunal group to be able to identify"

It can be important to be able to identify carabids as they can be used as model organisms to test hypotheses. As argued by Koivula (2011) they also have potential to be used as ecosystem health, dominance, keystone or early warning, e.g. climate change, indicators. This is provided knowledge of biodiversity covariation and large scale sampling networks can be established to assess their ability to function as indicators. Due to the fact that insects, such as carabids, can be difficult to sample and identify at scale, they may continue to be discounted in monitoring programmes (Andersen 1999). Being able to identify them may go someway towards rectifying this gap.

Reflection

This activity proved quite tricky in terms of identifying the species that I was provided with. The quality of specimen and mounting really do play an important role in how easy (or not!) it is to find features to allow you to follow a key. There were numerous occasions where the feature described was just not visible e.g. due to glue or placement which meant some guesswork was involved! I have learned that for this type of task, guidance and help from experts would be extremely useful. 

It was also useful gaining an understanding of how time consuming identifying individual specimens can be.

References

Koivula, M. (2011) 'Useful model organisms, indicators, or both? Ground beetles (Coleoptera, Carabidae) reflecting environmental conditions', ZooKeys, 100. Available at: https://doi.org/10.3897/zookeys.100.1533.

Luff M. L. (2007) The Carabidae (Ground Beetles) of Britain and Ireland. Handbooks for the Identification of British Insects, Vol. 4, Part 2, 2nd edition. Published for the Royal Entomological Society by the Field Studies Council.

National Biodiversity Network Trust (NBN Trust) (2023) About the NBN Atlas. Available at: https://nbnatlas.org/about-nbn-atlas/ (Accessed: 4 March 2024).

These references were used for the Carabidae mini-collection activity.

Andersen, A. N. (1999) 'Editorial', Journal of Insect Conservation, 3(2), pp. 61-64. Available at: https://doi.org/10.1023/A:1017202329114.

Hackston, M. (2019) Family Staphylinidae key to UK subfamilies. Keys for the identification of British Staphylinidae Available at: https://sites.google.com/view/mikes-insect-keys/mikes-insect-keys/keys-for-the-identification-of-british-beetles-coleoptera/keys-for-the-identification-of-british-staphylinidae (Accessed: 7 March 2024).

Hackston, M. (2022) Key to the British genera of subfamily Staphylininae. Keys for the identification of British Staphylinidae Available at: https://sites.google.com/view/mikes-insect-keys/mikes-insect-keys/keys-for-the-identification-of-british-beetles-coleoptera/keys-for-the-identification-of-british-staphylinidae (Accessed: 7 March 2024).