This species can be separated from the similar Phylloecus xanthostoma by its shining face with no punctures. By contrast P. xanthostoma has scattered punctures. P. linearis also has a pronounced interantennal furrow and a fourth antennal segment that is at least 0.75 times the length of segment 3. In P. xanthostoma the fourth antennal segment is at most 0.66 times the length of the third.
Phylloecus linearis larvae feed inside the stems of agrimony.
Size: 10 - 13mm.
Distribution: England, Wales
Flight period: May to June
Plant associations: Agrimonia eupatoria (common agrimony) (1)
(1.) Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
(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