Dialectica imperialella (Zeller, 1847)

Dialectica imperialella: mine on Symphytum officinale

Symphytum officinale, Belgium, prov. Liège, Oreye: mine with youg, colourless, larva; © Jean-Yves Baugnée

Dialectica imperialella: mine on Symphytum officinale

Symphytum officinale, Nieuwendam; mine, upper side

Dialectica imperialella: mine on Symphytum officinale

same mine, lower side

Dialectica imperialella: mine on Symphytum officinale

same mine again, lighted from behind, with full grown larva

Dialectica imperialella: detail of  start of mine on Symphytum officinale

Symphytum officinale, Niewendam: detail detail of the start of the mine.

Dialectica imperialella: mine on Pentaglottis sempervirens

Pentaglottis sempervirens, Belgium, West Flanders, Wielsbeke; © Steve Wullaert

Dialectica imperialella: mine on Pentaglottis sempervirens

underside of the leaf; exceptionally heavy infestation

Dialectica imperialella: mine on Echium plantagineum

Echium plantagineum, Belgium, prov Antwerp, Mol; © Carina Van Steenwinkel

mine

A number of eggs are deposited over a wide area of the underside of a leaf. The larvae make very wide epidermal galleries, that are hardly discernable, but for the tread thin line of frass that is glued to the floor of the mine. Gradually the larvae come together, and the mine becomes deeper, and finally becoming locally full depth. Only then the mine is apparent from above as some disconnected brownish spots. At the underside the mine is quite larger, membraneous. Pupation usually is outside the mine.

hostplants

Boraginaceae, oligophagous

Aegonychon purpurocaeruleum; Lithospermum officinale; Pulmonaria angustifolia, officinalis; Symphytum officinale.

Found in 2012 by Steve Wullaert on Pentaglottis sempervirens, by Carina Van Steenwinkel on Echium plantagineum.

phenology

Larvae in August – September (Emmet, Watkinson & Wilson, 1985a).

BENELUX

BE recorded (Phegea, 2009).

NE recorded (Kuchlein & de Vos, 1999a; Microlepidoptera.nl, 2009).

LUX recorded (Fauna Europaea, 2009).

distribution within Europe

From Denmark to the Pyrenees, Italy, and Romania, and from the UK to Russia and Ukraine (Fauna Europaea, 2009).

larva

pupa

Described by Patočka (2001b), Patočka & Turčáni (2005a).

synonyms

Acrocercops, Gracillaria imperialella.

references

Beiger (1980a), Bengtsson & Johansson (2011a), Biesenbaum (2010a), Buszko (1987a, 1992b), Doets (1946a), Drăghia (1968a), Emmet, Watkinson & Wilson (1985a), Huisman, Koster, van Nieukerken & Ulenberg (2001a., 2003a), Kasy (1965a), Kuchlein & Donner (1993a), Klimesch (1950c), Kuchlein & Donner (1993a), Kuchlein & de Vos (1999a), van Nieukerken, Gielis, Huisman, Koster, Kuchlein, van der Wolf & Wolschrijn (1993a), Patočka (2001b), Patočka & Turčáni (2005a), De Prins (2010a), De Prins & Steeman (2013a), Starý (1930a), Szőcs (1977a), Wieser & Huemer (1999a).

04/04/2017

pub 4.iv.2017 · mod 18.vii.2017