Archive | December, 2011

Christmas Mystery Cocoon

25 Dec

In honor of Christmas and the season of giving I bring you this mystery stocking stuffer, encountered in Argentina.

First, the present all wrapped up and hung on the tree.

Peeking inside...

Removing the first layer of wrapping...

The mystery present all unwrapped.

Ta-dah!  Your present seems to be some kind of hymenopteran pupae.  And if you can tell me what they are, that will be my present.

…merry Christmas and happy holidays, y’all!

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Gruesome leafcutter ant battle

23 Dec
Fighting leafcutter ants

Leafcutter ants attempt to rend and intruder limb from limb.

While scoping out leafcutters in Argentina we came across this (eerily quiet) scene of devastation and carnage as two opposing colonies of leafcutter ants battled for control of a nesting site.  Since leafcutters lack stings and venom the tactics were straight forward.  Surround and isolate an opponent and then attempt to tear her limbs off.

Check out the gruesome footage below.

Lots and lots of leafcutters

19 Dec
Colony of leaf cutter ants

A busy crowd of polymorphic leaf cutter ants at a large nest entrance.

Leafcutters are one of the most striking ants I’ve encountered, with their giant spiky bodies and stilt legs.  Unlike most other ants, leafcutters no longer retain the ability to sting or spray venom.  These ants are specialized for doing what their name implies–cutting leaves–and this can be seen clearly in the powerfully-jawed major workers.  In fact, the jaws latch on so strongly, staying clenched even after death, that beheaded workers are sometimes used to close wounds.  While in Argentina, my labmate Paul tried this out on a papercut.  Cure possibly less pleasant than the ailment.  Very effective, though.

Leafcutter ant heads used to pinch a cut closed.

Leafcutter ant heads used to pinch a cut closed (Photo courtesy P. Lenhart).

In my occasional encounters with leafcutters of the genus Atta, I was particularly impressed by the truly gigantic, sweeping nests a single colony can make.  Although not particularly tall, these mounds can cover a lot of ground, littered with cast off plant material and abuzz with busily working ants.  Apparently the 10-15 foot mounds I’ve seen don’t even come brush the upper limits:  Wikipedia says the central mound can grow to more than 100 feet across.

Giant ant hill of leaf-cutter ants.

Paul Lenhart observing a large mound of Atta leaf cutter ants in Argentina.

I’ve hardly ever encountered leafcutters in my area of Texas, but there is one large colony of Texas leafcutter ants (Atta texana) deep inside our local Lick Creek Park if you know where to look.

Related posts:

Ant farmer – Leafcutter Ants

Leafcutters on Parade