Coleophoridae

37.062 Basil Thyme Case-bearer Coleophora tricolor Walsingham, 1899

pRDB2

Similar species:

Forewing: 7.5 to 9mm

Habitats: Breckland.

Habits: The diurnal moth flies over Basil Thyme, especially at dusk. It also comes to light. It appears to be rare in Europe as well as Britain.

Foodplant: The larva initially feeds on the developing seeds in a floret of Basil Thyme. When the floret is empty it is cut off and used as a case. It then feeds on other florets. In October it mines a blade of grass and cuts it out to make a case in which it overwinters. In April it resumes mining grass blades, feeding on Upright Brome, Yorkshire-fog, Cock's-foot, Smaller cat's-tail, Smooth Meadow-grass or Crested Hair-grass. Unlike Coleophora lixella, when it wants to expand its case it discards its old one after mining a new blade and cutting out a larger case. This final ochreous, bivalved case is 9mm long, m.o. at a 25° angle. It pupates low on a grass stem or on adjacent vegetation.