Queen green-ants

North Queenslanders know green-ants very well. Their nests of woven leaves are common in our trees, and we learn to be cautious about pushing through shrubbery because the workers drop on intruders and bite quite painfully. But there is one stage of the life cycle we rarely see: the winged queen.

Large winged green ant
Winged queen green-ant

Unmated queens-to-be fly from existing colonies in the wet season and, if they are lucky, mate with winged males released at the same time and then establish their own new colonies.

We visited Magnetic Island yesterday and saw dozens of the winged queens. They looked like wasps but were clumsy fliers, often crash-landing into plants or people, and in spite of their powerful jaws they were not at all aggressive.

Green-ant queen
Another, sitting on my finger

The queen, like all flying ants, soon loses her wings. She will find a likely spot for a nest, and start laying eggs, and her children/workers will build the nest around her.

More pics: Worker and Nest construction  on Flickr.

All you ever wanted to know about Green-ants: A masterpiece of evolution – Oecophylla weaver ants by Ross H. CROZIER†, Philip S. NEWEY, Ellen A. SCHLÜNS & Simon K.A. ROBSON, Myrmecological News, 13, 57-71, Vienna, April 2010 (pdf)

Mimicry again – ant-spider

Small red and black insect
Ant? No, spider – Jumping Spider, in fact

A few days ago I showed a fly pretending to be a wasp (at bottom of previous post). On almost the same day I saw a little insect 5-6 mm long scurrying around on the broad strap-like leaf of a lily. It looked like an ant, but somehow not quite right. The camera let me stop it and magnify it, and see that it was in fact a spider.

Merely counting  the legs is enough to make that judgement, but we can go further. Looking at the eye pattern (you may need to click on the image to see the detail) puts it into the large family of Jumping Spiders, Salticidae. As roaming hunters, salticids depend totally on good eyesight and their upper central eyes are very large and face forward.

I was quite puzzled the first time I saw one (the one below), almost exactly a year ago: the body is very ant-like and the front end is … bizarre. We expect spiders to have two distinct sections, head (technically ‘cephalothorax’) and body (abdomen) but this one seems to be in three sections, with two fat rods sticking out in front of the head – as big as the head, too. They are actually its jaws, enormously enlarged to give it more of a three-part ant profile.

black ant-mimicking spider
Another ant-mimicking Jumping Spider

I haven’t been able to completely identify either of these two. I am fairly confident they are Myrmarachne species but haven’t found any just like them on the web. I don’t feel too guilty about that because there are ‘nearly 80 described species and more to come’ according to the experts. There’s a user-friendly introduction to them here, on the excellent Brisbane Insects site, and another here, on Arachne.org.