A genus of around fifteen species with a holarctic distribution. In Britain and Ireland the Fenusa are represented by two species.
The genus Fenusa can be characterised within the Fenusini by the following features. The antennae are nine segmented with the third segment longer than the fourth and the pedicel about as long as it is broad. The malar gap is less than the diameter of the front ocellus. The post-genal carina and the prepectus are both absent. In the forewing, the anal cell is complete with a small basal portion. Vein 2r joins RS distal to 3rm. The hind wing venation is simple with no enclosed cells. On the hind legs, the fourth tarsomere is strongly, apically produced beneath the fifth. The tarsal claws are simple. On the fore and middle legs, the tarsi are similar in length to their corresponding tibiae.
Larvae feed inside blister mines in the leaves of members of the Betulaceae family and shrubby members of the Rosaceae.
Fenusa dohrnii (Tischbein, 1846)
Fenusa pumila Leach, 1817
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
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
Smith, D. R. 1971: Nearctic Sawflies. III. Heterarthrinae: Adults and larvae (Hymenoptera: Tenthredinidae). - Technical Bulletin, U.S. Department of Agriculture, Washington 1420: 1-84
Smith, D. R. 1976: World genera of the leaf-mining sawfly tribe Fenusini (Hymenoptera: Tenthredinidae). - Entomologica scandinavica, Copenhagen 7: 253-260
Smith, D. R. 1981: Studies of the leaf-mining sawflies of the tribe Fenusini in Asia (Hymenoptera: Tenthredinidae). - Proceedings of the entomological Society of Washington, Washington 83(4): 763-771
Smith, D. R.; Altenhofer, E. 2011: The second record of a sawfly leafminer on Rosa, a new species of Fenusa (Hymenoptera: Tenthredinidae). - Proceedings of the entomological Society of Washington, Washington 113(1): 57-60.