Scientific opinion on the risks of introduction and spread of the cyst nematode Heterodera zeae on maize and other representatives of the family Poaceae in Bulgaria

An assessment of the risk of introduction and spread of Heterodera zeae on the territory of Bulgaria was prepared in connection to the report of the pest from Paleochori Kavallas, Greece, close to the Bulgarian border. H. zeae was described in the early 70s from India. The species is currently distributed in ten countries on four continents: Asia, Africa, Europe and North America. H. zeae is considered as one of the most economically important nematodes on corn and cereals in India and Pakistan. Its development and reproduction are favored by relatively high soil temperatures in the interval of 27 - 36ºС but the cysts remain viable for up to three years at 2ºС and successfully survive at -18ºС for 7 months. The known host range of the parasite consists exclusively of representatives of family Poaceae, which are cultivated from seeds and therefore are not traded internationally as planting material. Nevertheless, the nematode has been established in the rizosphere of non-host crops.BG; en; EFSAfocalpoint@mzh.government.b