 In their native habitat , all Amylostereum species have a minor importance as forest pests . The infestation through wood wasps does not assume greater dimensions and is , compared with other pests , almost insignificant . The infection rates are even lower during sexual reproduction via fruit bodies , as the wasps do not play a part in the process . Furthermore , the Amylostereum fungi are alone often incapable of <unk> healthy trees . They thus mostly act as <unk> . Pine <unk> in Australia , New Zealand , Africa and South America were shown to be susceptible to the Sirex <unk> ( Sirex noctilio ) , which was introduced there and which is associated with A. areolatum . The wasp 's <unk> secretion , its larvae and the fungus combine very effectively with each other and contribute to forest decline rates of up to 80 % . This is mainly owing to the poor water and nutrient supply of the trees , which can poorly reconcile the drought stress caused by infestation . S. noctilio was detected in North America in the 2000s ( decade ) ; in Canada alone , the total economic loss to the forestry industry caused by the Sirex – Amylostereum symbiosis could be as high as $ 254 million per year for the next 20 years . 
