They have discovered that when the food plant, Wild Thyme, comes under attack from the host ants, M.sabuleti (who eat the roots), it actually attracts females to lay on these particular plants by emitting a chemical that the butterfly detects! This benefits the Thyme as the caterpillars then predate the ant grubs and gives the the plant chance to recover, It also helps the Large Blue detect the Thyme closest to the correct ant species as if the larvae are taken into the nests of other species they are normally predated themselves.
See http://t.co/A07sH9DbE4
Kind regards
Mark
