Heterodera avenne is

Heterodera avenne is Cyst nematode.
Heterodera avenae, the cereal cyst nematode or European cyst nematode, is a plant pathogen and an obligate parasite of cereal crops including barley, oats, wheat and rye.
Cereal crops infected with this nematode are more susceptible to infection by fungal diseases such as rhizoctonia root rot.
The cysts can withstand harsh conditions and can be spread in soil, by agricultural machinery, by animals, by wind, by dust storms or by other means.