Firstly, weaver ants are are the first recorded organism ever to be used in 'biocontrol', their use being recorded back in 304AD by Chinese farmers to protect their fruit orchards. The descendants of these farmers, and other farmers across Asia and Africa still use the ants in exactly the same way today. Studies have found that these predatory, arboreal ants are much better at keeping fruit trees clean of important pests than other ground nesting ant species, and that farmers who look after their ant colonies (by leaving the undergrowth rough to discourage the ground-nesting species that are dominant in the shorter-canopied orchards, and by preventing pruning of nesting colonies) currently use on average half the chemical control needed by their neighbours who don't do this, and a significant proportion (20%) don't need any additional chemical control at all. So they're rather handy things to have around.
|Weaver ant nest, Ushongo, July 2011|
|There's money in that nest!|
So, there you go, three pretty remarkable things about weaver ants. If you've not seen them before but have been in East Africa, believe me, it's only because you've not been looking hard enough. Now you know how interesting they are, hopefully you won't overlook them next time! And that's before we start talking about how important to the ecology of many ecosystems are ants in general. Stories for a future post, I think...
Van Mele, P. (2007). A historical review of research on the weaver ant Oecophylla in biological control Agricultural and Forest Entomology DOI: 10.1111/j.1461-9563.2007.00350.x
Lioni, A., & Deneubourg, J. (2004). Collective decision through self-assembling Naturwissenschaften, 91 (5), 237-241 DOI: 10.1007/s00114-004-0519-7
Offenberg, J. (2011). Oecophylla smaragdina food conversion efficiency: prospects for ant farming Journal of Applied Entomology, 135 (8), 575-581 DOI: 10.1111/j.1439-0418.2010.01588.x