Euura poecilonota (Zaddach, 1876)

NON-GROUPED

Euura poecilonota - Marbled Birch Nematine

Nematus poecilonotus Zaddach, 1876
Nematus viridescens Cameron, 1885
Pteronidea subnitens Lindqvist, 1957

North to northern Scotland. Prous et al. (2021) note that the illustration of the penis valve in Benson (1958) of this species (as viridescens) actually shows that of hypoxantha and so most records of males are likely to be unsafe. Having said this, the species is usually parthenogenetic and hence males are extremely rare anyway (Musgrove, 2024).

Males are very rare and the species is likely parthenogenic in Europe. Very variable in colour and size but the pale colour is green in life fading to yellow. The head is light yellow with black antennae and a black frontal ocellar spot, which can occupy the whole occipital area. The thorax in the male is ​​black. The posterior corners of the pronotum, tegulae and more or less the mesopleura are pale. The female thorax is pale with black stripes on the mesonotum, and black marks on the scutellum and the scutellar appendage. The abdomen is pale below and mostly completely black above in the male, and in the female with a more or less broad middle stripe. The legs are pale with the apices of the tibiae and the tarsi black.

Euura poecilonota larvae feed on birches. Females cut distinctive slits through the leaf blade before depositing an elongate ovum adjacent to a secondary vein.  In captivity, females prefer to oviposit in low light levels around dawn and dusk. The ovum is green and may burst out of the leaf as it swells. Larvae hatch after 1-2 weeks.

Size: Female: 6.0 - 8.0mm.

GB IUCN status: Least Concern
GB rarity status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: April to September

Plant associations: Betula spp. (birches)