Discovering a hidden haven in the Latrobe Valley, Victoria, Australia

Posts tagged ‘rose pests’

Is the Harlequin Bug really the garden thug I should be worried about?

The William Shakespeare bloom that was the bud covered in Harlequin bugs a couple of days ago. It is quite unharmed, but...

I’ve been spending far too much time with the bugs. I was caught yesterday standing in the middle of a garden bed apparently staring, with great absorption, at nothing at all.

It was in fact a bug. I was watching its habits. It was very interesting.

Adult Dindymus versicolour 28th Jan 2010

I think I’ve confirmed that the shiny little red critters and multicoloured adult bug of my last post are Harlequin Bugs (Dindymus versicolour) which are a species of ‘true bugs’ related to Dysdercus cingulatus – the Cotton Stainer Bug and a member of the Pyrrhocoridae family.

The Australian Biological Resources Study which is a great resource on these bugs tells me this is a family of pentatomomorphan bugs. Now there’s a word. And here I was thinking that trying to work out botanical names was going to give me a headache*

Morwell National Park (which is not too far from where I live) has a great database of all the fauna and flora in the park and you can find a photo of the adult and young Dindymus versicolour bugs here. These photos confirmed that both the critters I was looking at were indeed the same bug.

My little friend ‘Dindy’ can be trouble as, according the The NSW Dept of Primary Industries:

“Harlequin bug, Dindymus versicolor, may attack a wide range of crop and ornamental plants, such as cotton, pome fruits, stone fruits, fig, grape, kurrajong, strawberry, vegetables, wisteria, dahlia and violet. When they are present in large numbers their feeding makes growing tips wilt or spoils fruit.”     Prime Facts – Sheet No 508, May 2007.  http://www.dpi.nsw.gov.au

My personal observations have revealed that:

a) They like to run around a lot.

b) They cluster together under leaves, adults seeming to babysit young.

c) They do a strange little ‘antenna dance’ when they meet each other doing their favourite activity, which is running around a lot.

d) They didn’t eat the first rose bud.

e) Nothing seems to be eating them.

f) The were found near the scene of the crime of this damaged rose bud…

Dindymus versicolour at the scene of the crime on a rose bud, but is he the true culprit, or has he been framed?

but then again so was this (hmm… more research ahead):

The real problem? I think it's a member of the leafhopper family and not sure if it's friend or foe.

and this…

The Passion Vine Hopper, which is a known sap sucker

In a nutshell it seems that Harlequin Bugs are a pest for commercial crops and the home garden. More bad news is that predators generally don’t find them to be a tasty snack as they smell and taste bad.

However some sources  suggest that they generally don’t do enough damage to be concerned about unless they appear in seriously large numbers, so there’s no need to panic and reach for the toxic spray. I do see the occasional badly damaged rose bud in my garden, but still have plenty of unharmed blooms to enjoy, and I haven’t yet seen with my own eyes who is actually doing the damage.  So I’m not risking killing hover flies and ladybugs to reduce the number of Harlequin bugs.

The Harlequin Bugs do have cousins in many parts of the world. I mentioned Bangchik’s  photo of red bugs on a Roselle from his ‘My Little Vegetable Garden’ Blog in Malaysia last time. Diana from Elephant’s Eye in South Africa also mentioned in the comments that she had a post recently on Shield bugs. Have a look at her amazing photos at Elephant’s Eye . Autumn Belle who keeps the wonderful  ‘My Nice Garden’ blog mentioned seeing them in her garden in Malaysia too.

I’d be very interested to know if you have them in your garden and if you have a photo to share. I’d be particularly interested to know if you have caught them in the act of eating one of your plants!

*I am pleased to announce that I now know my Brachyscombes from my Bracheantha. I think.

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