Subject: What are these tiny bugs?
Location: Melbourne Australia
April 9, 2014 1:11 am
I noticed thousands of these tiny little bugs sheltering on an indigenous tree & a neighbouring fence bollard today. i’m guessing the very small red ones are the nymph stage of the slightly larger ( still only a couple of millimeters ) black and white ones. I’m not sure if they would normally be in the tree as we have had an unusually large amount of rain in the last few days and they might have been trying to get to higher and dryer ground. They look like they might be some kind of harlequin beetle to me but if they are they have a long way to get to the size of the ones I sometimes see around.
Hopefully they don’t all survive to adult stage if that is the case as I will have trouble getting through my front door!
Signature: Nick A
We have been researching this for some time now, and we believe we may have the correct answer for you. Our first stop with Australian identifications is often the Brisbane Insect website, and we found some images of individual bugs that look somewhat like the winged adults in your incredible aggregation images. They are identified on the Brisbane Insect website as Coon Bugs or Cottonseed Bugs in the family Oxycarenidae and this information is supplied: “Oxycarenus luctuosus or A. [we presume a misprint that should be O.] arctatus, body length 5mm. The Cottonseed Bugs are small in size. Their back is triangular-patterned in black and white colours. We found them on our hibiscus plants on early spring. The nymphs are black in colour with blood-red abdomens.” That description matches your images. We did find the family represented on BugGuide where it states: “formerly treated under Lygaeidae” and “worldwide, mostly Old World, esp. Palaearctic & Afrotropical(1); in NA, more diverse in the west.” BugGuide also notes: “seed-eaters; hosts include plants in a dozen families (there are cotton pests in this family, but not in NA).” The Atlas of Living Australia has sightings in South Australia including on the border of Victoria, your state, but none close to Melbourne. Furthermore, there are none in Queensland, the state where the Brisbane website originates. No reported sightings doesn’t mean that they are not found there, just that no sightings have been reported to the Atlas of Living Australia. FlickR has a nice set of images of closeups of Coon Bugs, but none show the incredible aggregation that you have documented. Biodiversity Snapshots indicates they are found “Throughout Australia, including across Victoria.” Finally, we located an image on FlickR that is identified as Coon Bug, Oxycarenus arctatus, and there is a link to a pdf that states: “Coon bug, Oxycarenus arctatus, and cottonseed bug, Oxycarenus luctuosus, which are seed and fruit feeders, live by preference on malvaceous plants, such as the weed marshmallow, and hibiscus and cotton. Occasionally they swarm on other cultivated plants, damaging their growth, and on fruit trees, especially stone fruits. They suck the juices of the ripening fruits, leaving dried discoloured patches. If younger fruits are attacked they shrivel and exude gum. These small bugs often swarm around fowl yards, on fences and around the bases of walls of houses and outbuildings. The two species look similar, about 3 mm long and black and white as adults. The nymphs are black with blood-red abdomens.”
We are creating a new category for your Coon Bugs in the family Oxycarenidae.
Hi there again,
Many thanks for your searching efforts and yes, I can confirm that the bugs were indeed coon bugs after checking your links.
The tree they were congregating on ( due to all the rain I think ) is on the edge of a park that has a lot of the mallow weed in it so that makes sense also.
Once again thanks for your work. I am greatly impressed with your site and the work you did for me.
Nick from Melbourne.