Like some ants and termites, ambrosia beetles grow crops

People were not the first farmers. Several groups of ants, and one of termites, were tending fungal plantations for millions of years before Homo sapiens strode the planet. But ants and termites are social insects, able to spread the labour of running their estates among many pairs of jaws. Beetles, by contrast, are solitary. Yet work just published in the Proceedings of the Royal Society by Janina Diehl and Peter Biedermann of the University of Freiburg, in Germany, confirms the agricultural skills of at least one group of coleopterans.

The fruit-tree pinhole borer, as its name implies, bores holes in fruit trees. It lays its eggs and raises its young in the galleries thus created. Yet ambrosia beetles, of which this is a particularly pesky example, do not feed directly on the wood they bore into. Instead, they devour fungi which grow on the timber thus exposed.