A vocabulary of landscape — a landscape of words
1190 entries
truffle fly
A truffle fly is a small fly of the genus Suillia that finds truffles by smell and lays its eggs above them so the larvae can feed on the fungus. Hunters use it as an indicator: On a still afternoon, the flies hover in a loose column a foot or two above the ground and a column that holds position over one spot is a reasonable sign of something ripe underneath.
Etymology
The English name is for what the fly does. The method is old and is described in French and Italian truffle-hunting accounts long before anyone identified the species involved, and the flies were being watched as a locating tool for centuries before the biology was worked out.
Notes
The technique needs a windless day and good light, since the flies are small, and it is generally used to confirm ground rather than to search it.