Initially it feeds on the seeds of thyme and then uses the seedhead as a case. It overwinters in this case and starts feeding again in March on grass spp. It then makes a case from the mined blade of grass (British
The larva initially feeds on the seeds of thyme, feeding within
a floret and using this as its case. After overwintering, it changes
foodplants to grass, and eventually forms an elongated case from
two grass blade portions sewn together (UKMoths).
larva begins its life by eating out the ripe fruit of a thyme floret.
The emptied and dried calyx functions as its first case, in which
it hibernates. After hibernation the larva switches to grasses,
initially in its original thyme case. Later a new case is made out
of a mined grass leaf. This final case is about 11 mm long, two-valved,
straw-coloured, has a mouth angle of 25°, and bears a striking
resemblance to a grass spikelet (Bladmineerders van Europa).
Larva: The larvae of moths have a head capsule and chewing mouthparts with opposable mandibles (see video of a gracillarid larva feeding), six thoracic legs and abdominal legs (see examples).
Described by Suire (1961a) and Emmet et al. (1993a) (Bladmineerders van Europa).
Pupa: The pupae of moths have visible head appendages, wings and legs which lie in sheaths (see examples).
The adult is illustrated in UKMoths by Jon Baker.
and female genitalia are illustrated by the Lepidoptera Dissection Group.
Hosts in Great Britain & Ireland:
of year - larvae: August - May.
of year - adults: The adult moths fly in July and August, and
can be found on the wing in the afternoon as well as after dark
in Great Britain & Ireland: Widespread in Britain including Anglesey (VC52),
Bedfordshire (VC30), Caernarvonshire (VC49), Denbighshire (VC50), Derbyshire (VC57), East Sussex (VC14),
Glamorganshire (VC41), Kincardineshire (VC91), North Hampshire (VC12), North Somerset (VC6), South Wiltshire
and Surrey (NBN
Gateway) and the Channel Is. (Karsholt and van Nieukerken
in Fauna Europaea).
recorded in the Republic of Ireland (Karsholt and van Nieukerken
in Fauna Europaea). See also Ireland's NBDC interactive map.
NBN Grid Map:
elsewhere: Widespread in continental Europe including Albania,
Austria, Belgium, Croatia, Czech Republic, Danish mainland, Estonia,
Finland, French mainland, Germany, Hungary, Italian mainland, Latvia,
Liechtenstein, Lithuania, Luxembourg, Poland, Romania, Russia -
South, Slovakia, Spanish mainland, Sweden, Switzerland, The Netherlands,
Ukraine and Yugoslavia, Also recorded in Near East (Karsholt and
van Nieukerken in Fauna Europaea).
NBN Interactive Grid Maps of known host species:
British and Irish Parasitoids in Britain and elsewhere: Currently unknown.