 As a <unk> , cultures of the nematode <unk> <unk> have been used as biological control to protect trees since the 1980s . This parasite feeds on the mycelia of A. areolatum and is therefore a food competitor of wood wasp larvae . Where S. noctilio larvae are present , the parasite <unk> and <unk> the eggs of female wasps , causing them to be infertile . These infertile females lay infected eggs into new trees and thus spread the nematode . This control method has proven to be relatively successful to combat the Sirex – Amylostereum complex . In the Southern Hemisphere , where the technique has been widely employed , reductions of <unk> levels of 70 % – 100 % have been achieved . 
