Species of Ireland – A series by Dr Amanda Greer – Black Slip Wasp to Hedgehog

Category : Dr. Amanda Greer, Species of Ireland

We are lucky to have a team that live and breathe their chosen profession. Not only are they subject matter experts from fresh water ecology to wellness in nature, the team are as passionate about the environment when they are off the clock as they are when they are working.  Our Head of Sustainability, Dr Amanda Greer has taken some of her down time to share with the people of LinkedIn a daily post about the species she has encountered in her back garden.  Thanks to Amanda’s generosity we are reproducing the posts here on a weekly basis.

The Back Slip Wasp

My son came running into me full of excitement yesterday about this new bug he’d just found with the enormous stinger! It turned out to be this lady – the black slip wasp – harmless to humans as that long appendage is actually for laying eggs (an oviposter), but a ridiculously scary sight if you happen to be a caterpillar. This species reproduces by laying its eggs INSIDE caterpillars, where they grow and feed happily until they burst out one day ‘alien-style’. Personally I feel that this is a rather macabre re-rendering of the normal metamorphosis these caterpillars can expect to go through.

Gruesome to be sure, but a critical part of Ireland’s ecosystem and a gardener’s friend as they provide natural pest control. One of their favoured victims is the large white butterfly which is very fond of cabbages and the subject of tomorrow’s post.

species The Black Slip Wasp

The Black Slip Wasp
Latin Name: Pimpla rufipes
Irish Name: unknown (by me/google anyway, please comment if you know of one)

The Large White

When I was growing up, all common white butterflies were referred to (in exasperated tones) as ‘Cabbage Whites’. We were actually talking about 3 different but closely-related species: the Large White, the Small White, and the Green-Veined White. I’m talking about the Large White today as it’s the only one of the three that I’ve found in my garden so far.

These butterflies are fond of laying their eggs on cultivated cabbages and sprouts. It’s not just a preference, Large White caterpillars actually need to eat the mustard oils that plants in the cabbage family (or brassicas) produce in their leaves. Without this mustard oil fix, they won’t get the nutrients they need to survive. However, this diet has another handy side effect – all this spice makes the caterpillars taste disgusting to the birds that would happily gobble them up otherwise. Actually the effects last all the way to adulthood and even the butterflies give off an unpleasant, mustardy smell to help protect themselves!

Tomorrow’s post is about one of our native brassicas – the Shepherd’s Purse.

The Large White
Latin Name: Pieris brassicae – note brassicae for cabbage is even in the Latin name here!
Irish Name: Bánóg mhór



Shepherd’s Purse

Do you recognise the plant in the photograph? Some will, some won’t (don’t feel bad). This is actually shepherd’s purse – supposedly, the second most common flowering plant in the world, so small wonder I found it growing in my garden. It is so named because its heart-shaped seed pods look like the little purses that medieval peasants used to carry. The purses were made out of a pair of ram’s testicles, so I imagine that’s where both the heart-shape and the shepherd part of the name come into the equation!

The most marvellous thing about shepherd’s purse, in my opinion, is a bizarre adaptation designed to give its seedlings a good head-start in life. When the seeds fall and get wet, as they do in the rain, they produce a sweet and sticky substance that attract micro-organisms over and then traps them in the ooze. The microorganisms perish of course and their mortal remains then enrich the soil, meaning the seedlings can grow more vigorously. Ta dah! This is known as protocarnivory and is pretty ingenious.

Nematodes (round worms) are one of the microorganisms that shepherd’s purse seeds frequently feast on, and are the subject of Monday’s post.

Shepherd’s Purse
Latin Name: Capsella bursa-pastoris
Irish Name: Lus an sparáin




I did say I would start off these posts by discussing only wildlife that I have found in my garden. Now, I have to say that I haven’t actually FOUND nematodes in my garden as they are rather small; however, I can say for certain that they are there because it has been estimated that there are a million individual nematodes per square meter of soil. I’ll just say that again… 1,000,000 per m2! Good Lord.

 Some nematodes are parasitic on animals, some on plants, others are just free-living, live-and-let-live kinds of nematodes. The species I want to discuss now, is definitely not one of the laid-back species. Phasmarhabditis hermaphrodita seeks out slugs to infect so that it can complete its parasitic lifecycle. I don’t feel like going into the gory details this morning about what happens next, so I’ll let you work that out for yourself, however, there is one part of the story that you might not expect. This parasite actually changes the behaviour of its slug host. It’s Mind Control Monday!

 Normally, slugs would avoid areas with high populations of parasitic worms, for obvious reasons. However, once infected, the slug is attracted to areas where there are lots of P. hermaphroditas hanging out. More parasites hop on, and the host slug dies more quickly, which allows the nematode to enter the next stage of its lifecycle when it consumes the slug’s body. Even more remarkable is that when an infected slug is close to death it finds a secluded place, deep within the soil layer to go to die, so there will be little competition from other animals for the slug’s body, and P. hermaphrodita can feast in peace.

 Naturally, tomorrow’s post is about one of our native slug species: the netted slug.

Phasmarhabditis hermaphrodita




Netted Slug

When you see a slug do you wonder what species it is? Probably not, unless you’re used to ID’ing species. Nevertheless, it might interest you to know that we actually have more than 30 types of slug in Ireland. The most common Irish species, the netted slug, is our subject for today. The reason for the ‘netted’ part of the name should be obvious from the photograph; however, they are also called the grey field slug, and the grey garden slug. I prefer ‘netted’, it seems more flattering somehow, and also more accurate as they are highly variable in colour.

Slugs as we all know, are slimy creatures, but not all slime is created equal. The slime produced by the foot actually has fibres in it to prevent the slug from slipping back down any surface it climbs up (I’ll bet you never thought about how that works before). The body slime is much thicker and has the dual function of keeping the animal moist and being particularly distasteful to most animals. The netted slug produces a milky white slime when irritated.

I have personal experience of this, having had the misfortune to have once picked up the beer I was enjoying on a balmy summer’s evening, and find a thirsty slug already attached when it reached my lips. Tomorrow we will consider the hedgehog, who finds slugs much more appetising than I do!

Netted Slug
Latin Name: Deroceras reticulatum
Irish Name: drúchtín mogallach
Photo Credit: Pete Hillman



What’s in a name? Consider the hedgehog – a snuffly, rather loud creature that is often found in a hedge. Hedge-Hog, a very descriptive moniker. The Irish name for a hedgehog is Gráinneog, which means ugly little thing – also very descriptive, but a little unfair I think. I mean, look at that face! Young hedgehogs are called hoglets, which ALWAYS makes me smile.

Hedgehogs are our only land mammal that hibernates for the winter. They are looking for resting places around now actually, and when they find somewhere suitable they will settle in and sink into a torpor. Here their body temperature drops down to match the surroundings and their heartrate slows to about 10% of normal. They will start reappearing around March, although they do wake up, grab a bite to eat, and switch to a new nesting place on especially balmy winter days.

Obviously, hedgehogs are also known for their particular defence mechanism – rolling up into spiky football when frightened. They have 5,000 spikes ALL of which can be suddenly erected at the same time. Now that’s got to be painful. There’s not much in Ireland that would tackle a fully grown hedgehog in defence mode, except the odd (perhaps mad) badger.

I’ll leave you with this today – hedgehogs are quite good climbers; however, they can easily get stuck at the top of things as they are much less adept at climbing back down. Happily, they are also quite good at falling, and when all else fails it seems that they can roll up and get back down the fast way!

Tomorrow will have to be something from the hedge really won’t it? Blackberry seems like a good idea.

European Hedgehog
Latin Name: Erinaceus europaeus
Irish Name: Gráinneog