Crustaceans at the bottom of the garden!

Not all the small critters crawling about on little legs in suburban gardens are insects. Some are crustaceans. Like insects, crustaceans have a hard skeleton on the outside of their bodies and jointed legs. Crustaceans, however, have more than three pairs of legs (insects have three pairs), two pairs of antennae or feelers (insects have only one pair), and never have wings.

In fact, the crustaceans in the garden are more closely related to prawns, lobsters and crabs than they are to insects. Their closest relatives live in the sea, which is where the vast majority of the thousands of species of crustaceans live.

If you live in the damper eastern outskirts of Melbourne you may be lucky enough to have small yabbies burrowing in your lawn (see Information Sheet: Who’s digging in my lawn?). These are more familiar crustaceans than their smaller relatives and neighbours.

Three kinds of small crustaceans are common in suburban gardens in southern Australian cities.

Woodlice are oval, flat, dull-grey, segmented animals growing up to 17 mm long. The head has a pair of compound eyes and each of the first seven body segments supports a pair of short legs. Segments closer to the tail don’t have legs, but have shorter limbs underneath that act as ‘lungs’.

Woodlice dry out and die unless they remain sheltered from the direct sunlight. They spend most of their life hiding under logs, stones or pots, where they feed on rotting vegetation.

‘Woodlice’ is a plural word – the singular ‘woodlouse’ is rarely used. They are also called slaters – because they are the colour of slate.


Garden Slater, Porcellio scaber
Photographer: Alan Henderson / Source: Museum Victoria

They belong to the large group of crustaceans called Isopoda. The most common species in Australian gardens is the Garden Slater, Porcellio scaber, a name which means ‘rough little pig’ in Latin.

Pillbugs are oval, deep-bodied, shiny-grey and segmented. They grow to 18 mm long. Pillbugs are isopods like woodlice, so they have a similar arrangement of segments and legs. Unlike woodlice, they are able to roll into a tight ball when alarmed. Pillbugs also spend most of their time hiding in the grass, but occasionally are seen wandering in the sun.


Pillbug, Armadillidium vulgare
Photographer: Alan Henderson / Source Museum Victoria

The scientific name of the pillbug found in suburban gardens is Armadillidium vulgare, alluding to its similarity to an armadillo. Australians also call them ‘butcher-boys’.

Land hoppers are segmented, shiny, grey-brown crustaceans that are taller than they are wide. The seven pairs of legs are obvious, especially the longer ones near the back on which they can walk in a clumsy manner.


Land hopper, Arcitalitrus sylvaticus
Photographer: David Staples / Source: Museum Victoria

Land hoppers are usually seen when they hop, apparently in a hysterical manner, when they are disturbed from their preferred home in damp leaf-litter or under pot-plants in the garden. The common species can grow up to 9 mm long. Sometimes large numbers of land hoppers find their way indoors, where they quickly dry out to shrimp-coloured crisps.

Land hoppers belong to one of the most abundant groups of Crustacea, the Amphipoda. The common species in gardens in Melbourne and Sydney is called Arcitalitrus sylvaticus.

Native or foreign crustaceans?

The common woodlice and pillbugs in suburban gardens are not native Australian species. Both have been introduced to this country from Europe with the many garden plants brought here, probably starting in the 19th century. The two examples mentioned are among at least nine European species now in Australia.

The northern hemisphere species of isopods now dominate in gardens full of hundreds of other exotic species. Roses, camellias, hydrangeas and cabbages have all been imported to Australia. Just as these foreigners have replaced native plants in cities, so have exotic isopods replaced some of the 300 species of native terrestrial Australian isopods. Luckily most of these survive elsewhere, in forest and grassland litter, in just the sorts of places that woodlice and pillbugs usually inhabit.

Curiously, the reverse has happened with the Australian land hopper. Arcitalitrus sylvaticus is a native Australian species that is successful in most gardens. The same species has been imported to California and the UK, probably with Australian native plants taken overseas to beautify northern gardens.

Comments (38)

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Kirsten Mackintosh 20 October, 2010 20:04
What do pillbugs eat?
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Discovery Centre 22 October, 2010 09:41
Hi Kirsten, pillbugs feed on decaying organic matter.They are important in the environment in helping to breakdown organic matter and aiding the return of nutrients to the system.
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zo101 31 October, 2010 15:29
I did not know pillbugs and slaters where diferent breeds
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Corie 11 November, 2010 12:49
how do you control slaters and pillbugs? i don't want to completely removed them from my vegetable garden but i don't want them taking over either
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Tiffy Girl 9 February, 2011 17:07
Why dont slaters and pillbugs come out at daytime??????????????????????????????????
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Discovery Centre 18 February, 2011 15:03

Hi Tiffy, as it notes in the information above woodlice dry out and die unless they remain sheltered from the direct sunlight. To avoid becoming desiccated they spend most of their life hiding under logs, stones or pots, where they feed on rotting vegetation.

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Wendy 8 March, 2011 18:30
Hi - Could you please tell me the name of the Native slater(s). I am around the kinglake area and am trying to familarise myself with the native & imported slaters. Kind regards.
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Anita 15 March, 2011 21:53
Hi. Can you please tell me how the land hoppers are coming indoors in large numbers and what I can do to deter them? Thanks
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Discovery Centre 16 March, 2011 16:44

Hi Anita, it can sometimes be difficult keeping them out. Just bear in mind that they don't bite people and while they may come inside after heavy rain they usually dry out quite quickly and die. They can then just be swept up and thrown out. The links here and here will provide you with information on these creatures.

 

 

 

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Discovery Centre 20 March, 2011 14:51
Hi Wendy, unfortunately we don't have a staff member at the Museum with expertise in native terrestrial isopods to be able to provide the species list you are after. Australia does have a native fauna as you can see from this link looking at Lord Howe Island.   
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Nerida 29 May, 2011 15:48
Hi there, my daughter is doing a report on slaters/pillbugs and we want to know how long do they live for? Can't seem to find this info anywhere easily. Thanks.
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Joanne Brierley 24 September, 2013 15:50
Woodlouse usually live fr 1-2 years. Source from Wikipedia.
Ellie 4 August, 2011 01:49
I have a frog in this tank and I have a little pond in there with him. There is an air tube pumping little bubbles to the pond because I put a few tadpoles in it. Well, I put some wood shavings and plant decay in the pond for the tadpoles to eat and I have noticed that there are small, shrimp-like things swimming around. I did some reasearch and still have no idea what it is. I think it came in with the stuff I put in the cage. They are kinda see through so you can see their dark brown spine. I got one and put it under the microscope. The closest thing I came to was land hoppers but I think they are only in the UK. I live in Texas. If you have any ideas on what these things are I would really appreciate it. Thanks.
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Discovery Centre 6 August, 2011 15:35
Hi Ellie, the Discovery Centre would be very happy to identify your "land hoppers" for you. However, we would need to see either a photograph or the creature itself (as you live in Texas, a photo would be the best option).
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Gail 18 August, 2011 12:20
Hi, I have lawn shrimps in my outdoor inground spa. I have read that they can't survive in water and drown but these seem very healthy. I scoop out dozens of both live dark coloured ones and dead orange coloured ones daily. Do you think they fall in or can they breed in the water? Thanks.
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George 25 August, 2011 16:18
Are they safe for children? I'm having a new born and in my apartment, i find all these dead bugs but i don't want my child eating these bugs, but I'm sure he'll come across a few of them and eat them.
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Discovery Centre 27 August, 2011 16:18
Hi George, I wouldn't be too concerned about the possibility of a child eating some of these invertebrates. None of the things shown on this page are considered poisonous and I would imagine if your child does manage to grab a few, he or she will soon find they don't taste good and probably given them a wide berth. 
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Joseph 24 October, 2011 21:53
Hey guys, I just wanted to put this as a reference in a paper I'm doing and just wanted know who wrote this piece. Thanks :)
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Discovery Centre 27 October, 2011 11:49
Hi Joesph, thanks for checking, you don't need to cite any particular author in this case, just say Museum Victoria.
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shareen 15 February, 2012 11:46
i have managed to keep breeding albino slaters they look really cool. 4 very pink ones and two white ones
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Carol 8 March, 2012 14:03
Why are they classified as crustaceans and not myriapods (or something else) given that they have more walking legs than lobsters and crabs? They also have only one pair of antennae visible not two?
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Discovery Centre 17 March, 2012 12:30
Hi Carol, the slaters do have two pairs of antennae, but the second pair can be very hard to see. According to the book 'Worms to Wasps' by Mark Harvey and Alan Yen, crustaceans differ from myriapods in that they possess two-branched limbs while the myriapods possess limbs with only a single branch. In addition crustaceans have two pairs of antennae while the myriapods have only one pair. This book notes that due to the presence of many pairs of legs, Chilopoda, Symphyla, Diplopoda and Pauropoda are often referred to as myriapods, an informal grouping that has no taxonomic significance.  
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Ian 19 March, 2012 14:35
I have many mounds of clay/mud in my lawn. We have lived here for 40 years and havent had them before. Looking under them, there is a land hopper. I did import some yabbies for the pond, could theat have introduced them?
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Discovery Centre 19 March, 2012 16:22

Hello Ian,

To find out what species of hopper you have in your garden the Discovery Centre would be very happy to identify your 'hoppers' for you. However, we would need to see either a photograph or the creature itself. Please follow out identification guidelines here

Graeme 19 March, 2012 14:56
We have noticed many of these hoppers in the garden beds lately. Curious to know what they eat and if they bite humans or pets?
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Discovery Centre 23 March, 2012 14:32
Hi Graeme, these terrestrial amphipods generally feed on decaying plant matter; they do not bite people or pets. This link will provide you with some information on them.
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bailey 2 April, 2012 16:47
how long do the live for? cheers just wanna now please respond to me thanks so so so much
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Ashley 18 April, 2012 19:44
Hi, I keep both woodlice and pillbugs in a tank. Both have reproduced and I have over 100 now. I find them facinaiting and have noticed some of the woodlice are red. At first I thought that maybe it was a juvenile age related thing but only a few are red and they are a varying stages of life. Why is this? Are they albino? Or is it a recessive colour trait? If you could help me answer this question I would really appriciate it. Thankyou so much :) Vic, Australia
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Discovery Centre 19 April, 2012 13:17
Hi Ashley, our Live Exhibits staff have said the woodlice you have is undoubtedly Porcellio scaber, the common introduced species that is flatter than the pillbug. This species does occasionally throw up an orange-red form which appears to be genetically determined, but we’re not sure why it appears. It doesn’t seem to be a beneficial trait, as orange-red forms only occur as rarities but they do persist in populations over time.
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Ashley 19 April, 2012 17:25
Thankyou for your reply, I now know a little more about my woodlice ;) I was also wondering if there are a variety of woodlice and pillbugs found in victoria? Thankyou for all your help and response.
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Discovery Centre 30 April, 2012 13:16
Hi Ashley, unfortunately the Museum doesn't have an expert on staff in this area. Please see the response to Wendy on the 20th March 2011.  
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Iosif 6 July, 2012 16:18
I am from Costa Rica, and we have land hoppers in our garden. Is it possible that they belong to the same species mentiones in this article, or do they belong to another one? ..They look exactly the same and the description matches.
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do pill bugs or slaters roll into balls 21 October, 2012 18:59
do pill bugs or slaters roll into ballsdo pill bugs or slaters roll into ballsdo pill bugs or slaters roll into balls
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Discovery Centre 20 November, 2012 10:06

Hi Katie, woodlice are one of the easiest animals to rear and breed in large numbers. In fact if you keep skinks or any other animals in an enclosure with logs and leaves, woodlice will quickly appear out of nowhere. A terrarium with a soil substrate, bits of bark and leaf litter, will be an excellent home for them. Keep it relatively moist with a spray of water every couple of days, and add a small dish (such as a milk bottle lid) of cut vegetables or fish flakes.

Collect woodlice from under logs or stones and add them to the terrarium, and they should continue to breed in there as long as you maintain it.

 

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Sonya 10 April, 2013 22:13
If I were to collect some slaters and start a breeding colony would they be safe to use as feeders for reptiles? I'm assuming they would be.
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Discovery Centre 14 April, 2013 11:45

Hi Sonya,

Slaters are fine to feed to reptiles. They can be bred in large numbers as long as their environment is kept relatively moist - as land crustaceans, they need to breathe through gills. Slaters are also useful in a reptile enclosure as they help to keep it clean, consuming all the tiny bits of detritus and fungal spores that might otherwise accumulate.

Nicole 26 October, 2013 17:21
Hi there, I have had a very successful vegie garden in the last couple of years. But this year when i put my pumpkin seeds in as soon as they popped up the next day they were gone. I couldnt work out what was eating them. I then went for seedlings and the day after i put them in i returned to find them half eaten. I have now worked out they are pill bugs and they are definately eating them. There are there during the day and they were all around the base of the seedlings eating them. Just wondering what is the best way to get rid of them so i can have some pumpkins this year.
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Gower Street Kindergarten Blue Group 26 November, 2014 16:23
Hi, we are very interested in Butcher/Butchy Boys at kindergarten (There are lots in our vegie patch) and were wondering if you know why they are called that. Our teacher, Catriona has tried to find out but can't find any information anywhere. Thank You
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