Yponomeuta cf. malinellus

• Subfamily:
• Wingspan: 16-20 mm
• Flight period: Jun - Aug
• Spread: Common
• Host plants: Rosaceae

Information

The Yponomeuta malinellus also know as Apple Ermine is a moth of the Yponomeutidae family with a wingspan of 16-20 mm.
Moth widespread throughout Europe with the exception of Portugal, Slovenia and Croatia. *
Its range includes the temperate Palearctic ecozone and North America. ***
In Italy it is absent from the islands. *

The front wings of Yponomeuta malinellus are generally pure white and are spotted with black dots, usually 12 to 16, the hind wings are greyish and fringed.
Difficult to distinguish from related species except with genital dissection. In this case, the identification is almost certain, but not sure as the discovery was made in the vicinity of an apple orchard, a host plant of the species.

It has only one generation per year. Of mainly crepuscular activity, the adults are visible from July to the end of August. It overwinters in the larva stage inside the egg plaques.

The eggs are in groups from 20 to 95 by deposition, are arranged in convex, oval or elongated ooplaces, measure three 4 and 10 mm.
These egg plaques, yellowish after deposition, brown later, are generally deposited on the bark of the 2-year-old branches and resting under the armpit of the shoots or under the nodes.

The larva of the Yponomeuta malinellus is straw yellow in color at the 1st larval stage, the color of the caterpillar changes after each moult; slate-blue gray after the first moult, its pigmentation progressively lightens until it becomes yellowish gray in the next moult. ****
Each segment bears 2 black spots. The head is black, at the end of its development, the caterpillar reaches from 18 to 20 mm in length. **

The pupae are enclosed in a small white silky cocoon. They are arranged parallel to each other in the center of a collective texture or "chrysalis nest".
They are yellow or light green, with shades on the head or near the cremaster respectively of light brown / ocher or brown **

The caterpillar develops on Rosaceae, mainly on Malus sp. (apple tree), but also on Prunus sp. including Prunus dulcis (almond tree) and on Crataegus sp ..


* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/
*** http://antropocene.it/
**** Istruzione agraria online - https://www.agraria.org/entomologia-agraria/iponomeuta-del-melo.htm