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Green-headed ant (Rhytidoponera metallica)

10 Sep

The Green-headed ants (not to be confused with the Green Tree Ant-Oecophylla smaragdina) although beautiful close up, are not a lot of fun for people like me. I’m allergic to all sorts of things from antibiotics, to some plants, to apparently ant bites! Although I don’t get full anaphylaxis with ant bites (like I do with antibiotics), I do react to them more than the average person. Especially these guys.

I’ve been bitten on three different occasions by them, and every time a tiny little bite turns into a huge, swollen ordeal.

image

Back of my thigh from one bite.

This time, while walking through the front yard, I got two bites on my foot. One I actually felt, and when I looked down an ant was in another spot on my foot still biting.
image

So, I decided to investigate what it is about these guys that make me react so badly to them.

First of all, these ants don’t actually cause reaction from their bite. They have a stinger in their abdomen, which injects a
venom. Most of what I read, aside from the Queensland Museum site, made the effects from the sting seem very benign, with reaction lasting at most a day. My foot was swollen for at least 3 days, and even now (9 days later) it still itches near the stings.

The pain I would liken to a shot from a needle, than a burning sensation. It feels similar to a bee sting. After that, it’s painful with the swelling, feels very hot, and the true itching starts when the healing starts… and boy is it bad.

So, what in the venom causes all of this drama? Formic acid-a naturally occuring organic acid used in many applications. But most notably, the main ingredient in ant venom. 🐜

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Formic acid

These ants are common in yards,
so (needless to say) I’m going to be a lot more careful going shoeless, or sitting, in the grass from now on.

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So, what was it?

8 Aug

So, did you have a guess?

Now, before I give you the answer, let me explain a few things.  First, the creature (and I’m being careful not to give it away by choosing that word) in the picture is a mimic.  There are two reasons for mimicry (myrmecomorphy); to either fool predators or to fool prey.

Gum Leaf Katydid resemble ants in their early development.

 

There are four types of mimicry (more on those in a later post) but this particular guy is employing the Batesian Mimicry.  Batesian mimicry is when a there is a resemblance between one insect or spider that is unprotected and palatable (our guy) to another species that is unpalatable and protected (what he is mimicking).

So, what is this guy mimicking?

The Golden black ant.  And not only do they resemble them in appearance, but these guys go so far as to hang out with the ants, undetected!  And here’s how I figured out what it was — they also take their front two legs and wave them around like they’re antennae. and I noticed this guy suddenly walk on his ‘antennae’! What? Wait, let me count those legs…

1, 2, 3, 4, 5, 6… 7… 8!

What has eight legs?

Now you’re with me.

(Drum roll, please)

Introducing…the Golden Ant-mimicking Jumping Spider!

golden ant mimic

Yes! A spider.  And when I took him outside to get a better shot, he dropped off the bowl and hung from some web…which I was not able to capture.  Bummer.

To see my personal favourite example of mimicry, check out the post I did on the Bird-dropping Spider.