Acronicta (Viminia) rumicis
- Subfamily: Acronictinae
- Wingspan: 30-40 mm
- Flight period: Apr - Sep
- Spread: Common
- Host plants: Polyphagus
The Acronicta rumicis also called Knot Grass is a moth of the Noctuidae family, Acronictinae subfamily, with a wingspan of 30-40 mm.
It is distributed in most of Europe, it is absent from Iceland.
In Italy it is also present in the islands. *
Its range extends into northwest Africa in Europe and part of Asia as well as in Japan.
The wings of the Acronicta rumicis are gray, marbled with variation of whitish points, lines and black shades; bounded external line by a white spot on the submedian fold; hind wings suffused with brown.
The evolution of the moth was influenced by the industrial melanism that occurred in Europe in the late 19th and early 20th centuries, causing a dramatic increase in two aberrations salicin and lugubris , which have darker gray wings.
in some of its variations it may resemble other Acronicta species, but this moth displays a curved white mark near the rear edge of the wing anterior, also in melanic samples.
bivoltine moth adults are in flight from late April to July, in the first generation and from August to September in the second. It overwinters at the pupa stage.
The eggs are lenticular with raised center, they are reddish gray with a dark red dot in the center. **
The larva is brown in color with a black head; it has oblique white spots on the sides of the dorsal line as well as a white lateral line with red spots, it also has hairs with varying color from white to reddish yellow.
The chrysalis is dark brown / brown in color with numerous appendages on the Cremaster.
The larva is polyphagous and feeds on both herbaceous plants and deciduous trees and shrubs such as Salix caprea, Urtica, Rumex obtusifolius, Rubus fruticosus, Euphorbia cyparissias, Calluna vulgaris, Plantago lanceolata, Centaurea jacea, Taraxacum thistle, mint as well as deciduous trees and shrubs.
* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/
*** Roland Robineau, Guide de papillons nocturne de France, Delachaux et Niestlé, 2011 p.112