Cockroaches

07 March, 2010

Common shining cockroach - <I>Drymaplaneta communis</I>.
Common shining cockroach - Drymaplaneta communis.
Image: Alan Henderson
Source: Museum Victoria

Question: What is this huge black cockroach in my house and is it a pest species?

Answer: If your cockroach is shiny black and wingless with a white stripe around the edge of the top half of the body you probably have a species from the genus Drymaplaneta.

Cockroaches from this genus like moist, dark places such as under bark or in deep leaf litter and they can be brought into peoples' homes under the bark of firewood. With all the years of drought that Melbourne has been experiencing and the drive to reduce water use, many of us have been mulching our gardens. This has provided excellent conditions for these insects. Native cockroaches are actually very important insects in the environment and assist in breaking down organic matter.

In Melbourne we have been getting quite a few reports of these cockroaches wandering into peoples’ homes in the last few years, (in fact I had one in my kitchen last night). They may be attracted to water in our homes or may just be increasing in numbers in suburbia. As opposed to the introduced pest species which are very adept at hiding this native species can often be found wandering around in our homes without any obvious concern for its welfare. Given the negative reaction that most people have to cockroaches their presence often causes alarm.

There are hundreds of species of cockroach found in Australia, ranging from very small species to brilliantly coloured species to very large burrowing species from Queensland, capable of hissing. There are a handful of cockroaches which are recognised as pest species; these are all introduced species. The native species of cockroaches shouldn’t cause any problems that we are aware of. 

To discourage pest species of cockroach from entering your home it is important to minimise the 3 things that they require, food, water and shelter. Try not to leave piles of newspapers or magazines around that may provide shelter. Avoid leaving crumbs, uneaten pet food or other sources of food and make sure that dripping taps are fixed.

Comments (10)

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Maya 28 August, 2014 06:53
do these cockroaches become more active in spring? I know they are always there and spot them occasionally, but in this nice warm weather, I've seen dozens! I just leave them, they don't worry me, is that ok? or should I really move them out? with a toddler around it's too hard to keep the house clean enough.
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Discovery Centre 30 August, 2014 12:58
Hi Maya, most species of insect increase activity as we move from winter into spring. If the cockroaches you are seeing are the large, shiny, black ones with the white stripe around the edge these native ones shouldn't be anything to be too concerned about. There are a handful of species which are introduced which are less desirable as they can come in from drains and pipes and bring germs. Probably the most common of these species in Melbourne would be the German Cockroach, Blatella germanica. Search online for this species by image and if that is what you are getting there are a number of websites which will offer general advice on minimising cockroach numbers. Or if you can catch one take some images and send them to discoverycentre@museum.vic.gov.au and we'll confirm for you.  
Kaye Oreilly 26 May, 2014 10:16
Thanks very much for your site, was freaked out when i found one of these and just put black and white cockroach in google and your picture and explanation came straight up. So thanks. I found one in Churchill walking across my kitchen floor.
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Shane 12 April, 2014 21:05
Just moved in to a house In cranebourne and lately there are heaps of cockroaches we just chatch them and put them out side should we kill them there's heap of them help me please we have two kids and we are pretty clean people don't no wat to do help
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Discovery Centre 14 April, 2014 12:15
Hi Shane - sorry, MV can't provide pest control advice. All I would say is reduce habitat or hiding areas for them as much as possible, and contact your local council or a reputable pest control company for further advice.
Maima 28 November, 2013 15:12
Hi I need help to find out what the species of a cockroache is
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Discovery Centre 28 November, 2013 16:15

Hi Maima,

As in the above comment, send us an image of your cockroach and we can identify it for you.

Louise 20 February, 2013 09:48
I live in Melbourne, Australia, and I have recently grown concerned about cockroaches, as I believe one was trying to bite my lips the other night when I was asleep - I cant be sure, but I woke feeling some sort of a nip near my lip x 2, freaked out, I brushed away the general area, and found a cockroach on the floor beside my bed; after researching cockroaches, I now know that they do rarely bite as they are scouring for food - uugh! gross! I live near a bush reserve and have the occasional cockroach siting in my house, and try to be vigilent with cupboard cleaning etc but otherwise haven't worried too much about them in the past; but now I am going to be really vigilent - I am not keen on pesticides,as I believe they are probably also harmful to humans. It was the common black cockroach found in this area, very similar to the one pictured however I haven't noticed a white stripe around the edge of the body.
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Discovery Centre 14 March, 2011 15:50
Hi Elizabeth, if you can get a good quality image of the cockroach please feel free to email it to discoverycentre@museum.vic.gov.au and we will try and identify it for you.
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elizabeth ferguson 14 March, 2011 12:28
We have a species here which is large,black with white spots down the side of its body. I believe this is a native species. Is this right?
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