Hurley, Brett PhillipHatting, H.J.Wingfield, Michael J.Klepzig, KierSlippers, Bernard2012-06-142012-06-142012-06B.P. Hurley, H.J. Hatting, M.J. Wingfield, K.D. Klepzig & B. Slippers, The influence of Amylostereum areolatum diversity and competitive interactions on the fitness of the Sirex parasitic nematode Deladenus siricidicola, Biological Control, vol. 61, no. 3, pp. 207-214 (2012), doi: 10.1016/j.biocontrol.2012.02.0061049-9644 (print)1090-2112 (online)10.1016/j.biocontrol.2012.02.006http://hdl.handle.net/2263/19199The Sirex noctilio (woodwasp)–Amylostereum areolatum (fungus) complex has caused substantial losses to pine industries in its introduced range. The nematode Deladenus siricidicola that parasitizes S. noctilio and feeds on A. areolatum is widely used as a biological control agent for S. noctilio, but not with consistent success. This variable success could be due to factors that influence the feeding and reproductive ability of the nematode on A. areolatum.We test two main hypotheses that emerge from this prediction. First, we compared the survival of D. siricidicola on the South African field strain and the Australian laboratory strain of A. areolatum, to examine a possible incompatibility between nematode and fungal strain. Second, we examined the competitive interactions of these two A. areolatum strains with two common sapstain fungi, Diplodia pinea and Ophiostoma ips, that occur in S. noctilio infested trees in South Africa. The effect of water potential on the outcome of these fungal interactions was also considered. The data showed that D. siricidicola survives at comparable levels on the two A. areolatum strains. Water potential of the media significantly influenced growth of the fungi and their ability to capture host resource in competitive interactions. D. pinea competed increasingly better against A. areolatum with decreasing water potential. The results suggest that competitive interactions between A. areolatum and sapstain fungi could negatively influence the success of D. siricidicola, especially under conditions of lowered water potential.en© 2012 Elsevier Inc. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Bilogical Control. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biological Control, vol. 61, issue 3, June 2012, doi: 10.1016/j.biocontrol.2012.02.006.Amylostereum areolatumDeladenus siricidicolaSapstain fungiBiological controlPine -- South AfricaForests and forestry -- South AfricaPest managementSirex noctilioSirexFungiPostprint Article