Genus Hemichroa

Hemichroa

There are thought to be around eleven species of Hemichroa globally with a holarctic distribution. In Britain and Ireland there are two species.

The genus Hemichroa can be characterised within the Nematinae by the following features. The antennae are at least twice as long as the width of the head and are slender in form. The pedicel is broader than it is long. The prepectus is present and is triangular in shape and separated from the mesepisternum by a suture. In the forewing, the anal cell is widely divided into a basal and apical portion, though vein 2A+3A may be very faint in the basal portion. The vein 2r-rs in the marginal cell may be present or absent and vein 2m-cu meets cell 1Rs. The tarsal claws have a long inner tooth .

Larvae feed on the leaves of various trees, especially those in the Rosaceae, Betulaceae, and Salicaceae.

Species list:

Hemichroa australis (Serville, 1823)

Hemichroa crocea (Geoffroy, 1785)

References:

Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

Boevé, J.-L. 2015: Multimodal defensive strategies in larvae of two Hemichroa sawfly species. - Journal of Hymenoptera Research 46: 25-33.

Chevin, H. 1998: Biologie d'Hemichroa australis (Lepeletier, 1823) (= H. alni L., 1767) (Hym. Tenthredinidae, Nematinae). - Bulletin des Naturalistes des Yvelines, Versailles ser. 5, 25: 7-11

Hograefe, T. 1984: Substrat-Stridulation bei koloniebildenden Blattwespenlarven von Hemichroa crocea (Geoff.) (Hymenoptera: Tenthredinidae). - Zoologischer Anzeiger, Jena 213(3-4): 234-241

Hopping, G. R. 1937: Sawfly biologies No. 2, Hemichroa crocea Geoffroy. - The Canadian Entomologist, Orillia 69: 243-249

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

Prous, M., Liston, A., Kramp, K., Savina, H., Vårdal, H. and Taeger, A., 2019. The West Palaearctic genera of Nematinae (Hymenoptera, Tenthredinidae). ZooKeys, 875, p.63.

Saini, M. S.; Vasu, V. 2004: Review of the genus Hemichroa Stephens (Hymenoptera: Symphyta: Tenthredinidae: Nematinae) from the Oriental Region. - Zoos' Print Journal, Coimbatore 19(6): 1487-1491

Smith, D. R. 1975: The sawfly genus Hemichroa Stephens: A review of species (Hymenoptera: Tenthredinidae). - Entomologica scandinavica, Copenhagen 6: 297-302

Speight, M. C. D. & Moller, G. J. 1979: Amauronematus mundus, Hemichroa australis and Nematus brevivalvis: sawflies new to Ireland, with notes on some other Irish sawflies (Hymenoptera: Symphyta). - The Irish Naturalists' Journal, Belfast 19(12): 443-445

Togashi, I. 1990: A new species of the Hemichroa crocea group (Hymenoptera: Tenthredinidae) from Japan, with a key to species. - Proceedings of the Japanese Society of Systematic Zoology, Tokyo 42: 42-45

Togashi, I. 1990: Japanense and Korean sawflies of the genus Hemichroa Stephens (Hymenoptera: Tenthredinidae). - Transactions of the Shikoku Entomological Society, Matsuyama 19(3): 109-116