Lamington NP: A crazy dancer on the forest floor
On the second day of our Lamington trip we came across a strange phenomenon on the forest floor beside one of the paths through the rainforest. Something really was behaving like a mad thing.
It appeared to be performing a crazy dance, but was moving so fast that it was just a blur. It was only by looking at my photos later that I was able to identify it as a crane fly.
My photos in sequence showed the long-legged fly in flight, then very briefly touching the end of its abdomen to the ground, then flying up again. It repeated this process over and over again. I have to assume that it was laying eggs in the leaf litter, and that every descent to the ground meant another egg was deposited.
The whole process was very rapid. It was only on the ground for a second, and then two seconds later was in another position depositing another egg.
Most of my photos were very blurry, due to the rapid movement, small size, and lack of light, but I have put together a little sequence of three successive photos, so that you can see what was happening. The white arrows show the position of the fly in the photos.
I only really managed one more or less, clear shot (see below).
As you can see, craneflies look like very large mosquitoes, but although they are both in the fly Order (Diptera) they belong to different groups. Crane flies belong to the Family Tipulidae. Unlike mosquitoes, they are not parasitic and do not suck blood. Like all flies, crane flies only have one pair of wings. People generally encounter them helplessly trapped by their long legs in spiders' webs around the house somewhere.
Most crane flies deposit their eggs in water but some lay eggs in damp places including leaf litter. There, the maggot-like larvae develop, mostly eating decaying plant matter, and pupate before becoming, for a very short time, an adult.
I wasn't able to identify the species. It doesn't seem to be amongst the species shown for the Brisbane area, at this website:
http://www.brisbaneinsects.com/brisbane_flies/TIPULIDAE.htm
