This month’s blog comes to us courtesy of Dawid Martyniuk, a Zoology student at the University of Reading.
Lifting a log or stone, you may have noticed a centipede quickly scurrying away and squeezing itself into a crevice or under leaves, disappearing from sight. Since they are so fast, the only observations you may be able to make is that they are brownish, with long bodies, antennae, and many legs. But centipedes are much more than multi-legged, scurrying creatures; they have a diverse range of shapes or sizes and possess many interesting and complex structures seen only up-close. Although fierce and vicious predators to other small organisms they share their habitat with, they (British species) are harmless to humans and fascinating to observe.
I have always shown some slight interest in centipedes, but after taking a Centipede Identification course with the FSC (Field Studies Council), my centipede Identification skills have considerably improved, as has my interest in them, and I hope that you will be able to say the same after reading this short guide that I have put together on some of the most common centipede species on Campus.
The most common species on Campus, Lithobius variegatus is quite large and very distinct. It has Yellowish-brown colouration with a faint pattern and paler legs. The main way to distinguish this species from others is to look at the rear legs which are distinctly banded with pale and dark bands. This species also has larger forcipules (jaws) compared to other species.
Lithobius forficatus is also very common and arguably the largest species on Campus. It is brown and has distinct eyes and 15 pairs of legs (adult), typical characteristics of Lithobiomorph centipedes. the main difference separating it from other brown species is its large size of up to 3cm and the sharp projections on the edges of the 9th, 11th, and 13th tergites (segment plates).
This species is brown like Lithobius forficatus, but much smaller, to a maximum of 1cm long. The legs also appear slightly shorter, and its eyes are made up of only 3 ocelli (lenses) each, making it seem like the centipede has a row of 3 eyes on either side of the head, although this is very tricky to see, even with a microscope/hand lens. The antennae of this centipede are made up of 23-27 segments each
Like other members of the Order Scolopendromorpha ,it is relatively long, orange with long hind legs, and no eyes. Cryptops hortensis has a ‘prefemoral groove’, a distinct dent or depression along the underside of the first segments of the last pair of legs. This structure distinguishes it from other Cryptops species found in the UK and can be seen by temporarily putting the centipede into a clear, flat plastic bag, and looking at its underside through a hand lens or microscope. They tend to lose a hind leg when threatened, so finding individuals missing a hind leg or two is normal.
This species is very long and blind, characteristics typical of the Order Geophilomorpha. It has a reddish head and yellowish body that can grow to a modest 2cm in length. Individuals have 37-43 pairs of legs and 4 ‘coxal pores’ (holes located on the underside, behind the last pair of legs) which can only be viewed with a good hand lens or microscope. A very similar species, Geophilus truncorum also exists on Campus, but it has 37-41 pairs of legs and its hind legs have a claw at the end, whereas the hind legs of Schendyla nemorensis have no claw and appear more ‘swollen’.
Another Geophilomorph with a reddish head and yellow body like Schendyla nemorensis, but this species is much larger, reaching lengths of up to 4.5cm. It has a claw at the end of its hind legs like Geophilus truncorum but has 49-57 pairs of legs. Another useful characteristic is the long antennae which are almost 5 times the length of the head.
The longest centipede on Campus, growing to a huge 7cm, and one with the most legs too, boasting 77-83 pairs of legs. The hind legs are thin, claw-less, curving outwards, and there are many small coxal pores present. Like other Geophilomorphs, they can be found under logs and stones, but also underground, pushing their way through the soil in search of prey. This species seems to stay deeper underground during winter but is common under wood in spring and summer.
Now that you have read this guide, maybe the next time you see a centipede you will be curious enough to have a closer look and try and give a go at identifying it (If you can catch it!). This guide is relatively basic, so if you would like to read about other species and more features useful in centipede identification, I highly recommend the AIDGAP Key to British Centipedes available at: https://www.field-studies-council.org/shop/publications/centipedes-aidgap/
or just a look at the BMIG species list: https://www.bmig.org.uk/checklist/centipede-checklist.
Findings can be submitted to irecord.org.uk to improve current distribution maps and aid researchers.
Many thanks to Dawid! If you’re interested in contributing to the Whiteknights blog, please get in tough with Vicky Boult: v.l.boult(at)reading.ac.uk.