Abstract
Mitodiplosis graminis Kieffer, the only species of the genus Mitodiplosis (Diptera: Cecidomyiidae), was described in 1914 as the causative agent of an unspecified gall on pyp grass Ehrharta villosa (Poaceae) in South Africa. The type specimens are presumed lost. We reared all developmental stages of the gall midge, redescribe here the male and female, and describe for the first time the gall, egg, larva and the pupa. Diagnosis of the genus Mitodiplosis is extended. The gall is a large thickening of the stem that becomes malformed and does not produce flowers. Pyp grass is an environmental weed in Australia and New Zealand and M. graminis can potentially be used as a biological control agent. With a wing length of over 6 mm in some specimens, M. graminis is one of the largest species of Cecidomyiidae.
References
Biosecurity New Zealand (2009) Pyp grass Ehrharta villosa. Last Updated 26 March 2009. Available from: https://apps.mpi.govt.nz/applications/nzpests-view/Article/610/Pyp-grass (accessed 12 December 2018)
Fish, L. & Victor, J.E. (2005) Ehrharta villosa J.H.Schult. var. villosa. National Assessment: Red List of South African Plants. Version 2017.1. Available from: http://redlist.sanbi.org/species.php?species=1357-49 (accessed 21 December 2018)
Gagné, R.J. & Jaschhof, M. (2017) A Catalog of the Cecidomyiidae (Diptera) of the World. 4th Edition. Digital. U.S. Department of Agriculture, c/o Smithsonian Institution, Washington, D.C. Available from: https://www.ars.usda.gov/ARSUserFiles/80420580/Gagne_2017_World_Cat_4th_ed.pdf (accessed 10 January 2019)
Gibbs, R.G.E. (1987) Taxonomy of the genus Ehrharta (Poaceae) in southern Africa: the Villosa group. Bothalia, 17 (2), 191–194.
https://doi.org/10.4102/abc.v17i2.1035
Kieffer, J.-J. (1914) Neue Gallmücken aus Süd-Afrika. Centralblatt für Bakteriologie, Parasitenkunde und Infektionskrankheiten, 40 (2), 514–517.
Swart, A., Subbotin, S.A., Tiedt, L.R. & Riley, I.T. (2004) Anguina woodi sp. n. (Tylenchida: Anguinidae) from dune grass, Ehrharta villosa, in South Africa. Nematology, 6 (1), 129–144.
https://doi.org/10.1163/156854104323073008
Taylor, G.S. & Davies, K.A. (2010) The gall fly, Fergusonina lockharti Tonnoir (Diptera: Fergusoninidae) and description of its associated nematode, Fergusobia brittenae sp. nov. (Tylenchida: Neotylenchidae). Journal of Natural History, 44 (15–16), 927–957.
https://doi.org/10.1080/00222930903383545
Weeds of Australia (2018) Ehrharta villosa. Available from: https://keyserver.lucidcentral.org/weeds/data/media/Html/ehrharta_villosa (accessed 12 December 2018)