Euura sylvestris (Cameron, 1884)

EUURA BERGMANNI GROUP

Euura sylvestris - Fleur-de-lis Willow Nematine

Nematus sylvestris Cameron, 1884
Pteronidea disparoides Lindqvist, 1969
Nematus disparoides (Lindqvist, 1969)
Euura disparoides (Lindqvist, 1969)

There are scattered records north to southern Scotland, although some remain uncertain due to changes in taxonomy. The type specimen was taken by Cameron near Glasgow in or before 1884. There is then a long period with no confirmed records, although it is possible that the taxon referred to as Nematus ponojense by Benson (1958) (a handful of records from southern Scotland and northern England in the 1940/50s) - might be sylvestris. However this remains highly uncertain to date (M. Prous pers. comm.). Three records of sylvestris in 2009 and 2012 were made by experienced workers who should have been aware of relevant synonymies, with a further three records from 2021-23 following the publication of a new revision by Prous et al. (2021) (Musgrove, 2024).

Coloured green in life. Specimens need to be determined by examination of the saw or penis valve. The female is similar to Euura bergmanni and the oligospila group. They may be marked with black on the upper surface of the antennae, a small ocellar mark and a small spot behind the postocellar area, on the mesonotum, adjacent to the scutellum, the scutellar appendage, small dot-shaped spots in front of the scutellum and the abdomen which is mostly blackened only in the middle of the basal tergite. The male is like the female, but with black on a large frontal postocellar stain, the occipital area, most of the mesonotum, the scutellum and a broad streak on the dorsum of the abdomen.

Euura sylvestris larvae have a characteristic fleur-de-lis pattern on the lateral facesand are associated with willows and occasionally aspen.

Jump to other Euura bergmanni group species

Size: Female: 5.0 - 6.5mm, male: 5.0 - 6.0mm.

GB IUCN status: Near Threatened
GB rarity status: Nationally Scarce

Distribution: England, Scotland, Wales

Flight period: Assumed May to June, July to August

Plant associations: Salix spp. and Populus tremula (willows and aspen)