Food Plant: Symphytum officiniale (Common comfrey), Pulmonaria longifolia (narrow-leaved Lungwort)

Egg: underside, near to the rib

Mine: August-September

Notes: Formerly Acrocercops imperialella. A very rare miner in the UK, found in damp woodland and fens. Known from four fenland sites in the UK in Cambridgeshire, Huntingdonshire and recently (Barton, 2018) in Suffolk. Rediscovered in the Isle of Wight (Beavan, 2021).The initial gallery is soon absorbed into a blotch. The blotch is squarish as the larva eats through the leaf parenchyma to the upper epidermis. The blotch turns brown and care must be taken to distinguish these mines from diptera - which can form blackish blotches. Pupation can occur inside or on the leaf surface - this was the case with on S.officinale and P sempervivens.whereas with E. plantagineum pupation took place inside the leaf (Carina van Steenwinkel pers.comm.). In Southern Britain the foodplant is Pulmonaria longifolia (narrow-leaved Lungwort) notPulmonaria officinalis (Lungwort) (Beavan, 2021), whereas in Eastern England it is Symphytum officiniale (Common comfrey).

National Status: pRDB1

Bradley No: 311

Data: 26.vi.2005, Amsterdam, Netherlands

Image:© Willem Ellis

References:
Barton I (2018), Dialectica imperialella (Zeller, 1847) (Lep.: Gracillariidae) in VC28; new to Suffolk. Ent Rec J Var, 130, p24-28
Beavan SD (2021), Dialectica imperialella (Zeller,1847)(Lepidoptera: Gracillariidae) rediscovered on the Isle of Wight after 45 years and consideration of one of its larval foodplants, Entomologist's Gazette 72,4 p221-228
Langmaid J R, Palmer S M, Young M R (2018), A Field Guide to the Smalller Moths of Great Britain and Ireland