Added to the British list by Liston on the basis of a lectotype collected in 1838 by Newman in the London area. According to Newman's original description this is an almost entirely black sawfly with reddish costa. Reddish-brown are the apices of the femora, the tibiae and the basal tarsal segments.
Phylloecus faunus larvae tunnel into the pith inside the growing tip of first year blackberry stems. The mature larva spins a cocoon in the tunnel and the adult emerges from the stem the following spring.
Flight period: April to June
Plant associations: Rubus fruticosus agg. (blackberries) (1)
(1.) Bruzzese, E., 1982. The host specificity of Hartigia albomaculatus (Hym.: Cephidae] and its potential effectiveness in the biological control of European blackberry. Entomophaga, 27(3), pp.335-342.
(2.) Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168
(3.) Newman E (1838) Entomological notes. The Entomological Magazine 5[1837–1838](2, 4, 5): 483–500.