The present invention relates to a method for determining the presence of a cyst nematode in a sample comprising the steps of: providing a pair of bidirectional oligonucleotide primers or an oligonucleotide probe that hybridizes specifically, under stringent hybridization conditions, to a nucleic acid sequence encoding the SSU rRNA or LSU rRNA, or the complement or transcript thereof, of a sub genus-cluster of nematodes, said subgenus-cluster comprising cyst nematodes belonging to at least one species of nematode, and wherein said primers or probe do not hybridize to a nucleic acid sequence encoding the LSU rRNA, or the complement or transcript thereof, of cyst nematodes not part of said subgenus-cluster of cyst nematodes; providing a sample in which the presence of the cyst nematode is to be detected, and performing a nucleic acid detection assay on said sample using said pair of bidirectional oligonucleotide primers or said oligonucleotide probe.