Argentine Ants: conquering new niches thru peace and aphid-herding

This image was extremely fun to work on.  It was for an article for Natural History magazine about the triumphant success of so called Argentine Ants. I chose the “pioneer” theme of the wagon, bonnet, cowboy hat, aphid-oxen etc.  to make it a very easy to grasp visual metaphor.

After I had done it, I wondered if it would have been better to have the same main wagon but instead of the other following wagons, it would ride through a vast expanse of thousands of dead ants, (as the one in the foreground).  It perhaps would better suggest the unlikely success of “sweepstakes dispersal”.  Such an image would pay homage to  all the other ants that didn’t make it!

But I digress.  I am quite happy with the image, which is a combination of watercolor and digital coloring.

Back to the ants:  they are known scientifically as Linepithema humile and they have a tendency to become successful at exploiting niches at whatever hostile shore a soft pregnant queen at the brink of death happens to wash up on.

In short, they spend their efforts on food, (not warring with other militant ants), have a propensity to herd scale insects and aphids, and perhaps most importantly have an uncanny ability to intermingle amongst other “colonists”.  Here is a fascinating excerpt from wikipedia:

“They have been extraordinarily successful, in part, because different nests of the introduced Argentine ants seldom attack or compete with each other, unlike most other species of ant. In their introduced range, their genetic makeup is so uniform that individuals from one nest can mingle in a neighboring nest without being attacked. Thus, in most of their introduced range they form “supercolonies”. “Some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests.

In contrast, native populations are more genetically diverse, genetically differentiated (among colonies and across space), and form colonies that are much smaller than the supercolonies that dominate the introduced range. Argentine ants in their native South America also co-exist with many other species of ants, and do not attain the high population densities that characterize introduced populations.

I hope other illustrations like this one will come my way.

I hope you like it, let me know what you think.

how do aquatic insects use the surface of water?

illustration showing how 3 aquatic insects use the surface tension in water

I love the fact that many insects pass through an aquatic stage on their way towards maturity.  And those that spend their whole lives either in water, or never more than metatarsal-length away from it…fascinating!

The myriad different paths of evolution that those insects, (and arachnids for that matter) have evolved to make a go of it full time are just amazing to ponder.  I did this project to explore (just) 3 ways that 2 hemipterans and 1 coleopteran use surface tension differently.

The gerrid, (“water skeeter”) seems to hover on the water’s surface, propped up on its legtips inside concave cups of unpierced surface tension.  Its mindboggling to watch how quickly they beat their way across a body of water.

The gyrinid has a 2 pairs of eyes!  One to monitor what is going on above the surface, and one to track the comings and goings below.  It beats its paddle-like legs and rests “within” the surface…meaning a waterline bisects its gorgeous hydrodynamic curves.

The Notonectid is something like the Gerrid but in an inverse paradigm…it rests what we think of as upside down with its leg tips resting on the surface tension…but from below!  How cool is that?

the ratios of these insects to one another have been modified slightly to allow them to mingle comfortably on the page.  you can check out this image in greater resolution in my portfolio.