Ants are laying siege to the world’s chocolate supply – Ed Yong – Aeon
▻http://www.aeonmagazine.com/nature-and-cosmos/what-can-ants-teach-us-about-agriculture
Ants have been farming for millions of years longer than humans. These particular ants herd mealybugs — small, sap-sucking insects that look like woodlice dipped in flour. The ants shepherd and protect the mealybugs so they can ‘milk’ the sugary nutritious fluids in their waste. The bugs used to drink primarily from local rainforest trees, but when humans started clearing the forest to make way for cocoa, the ants adapted, by driving their livestock into the fresh cocoa pastures.
This strategy shift entangled the cocoa trees in a web of pests and pestilence. When mealybugs drink from trees, they inject them with a pathogen called cacao swollen shoot virus (CSSV). In local rainforest trees, the effects of CSSV are mild, but cocoa — a newcomer to these forests — hasn’t had a chance to evolve countermeasures. As a result, the virus pummels the trees, swelling their shoots and roots well beyond their usual size while draining the colour from their leaves. Before long, often only a few years, the trees die.