A study of fungal endoparasitism of the cereal cyst nematode (Heterodera avenae) by scanning electron microscopy

Abstract

The sequential development of fungal endoparasites from eggs of the cereal cyst nematode (Heterodera avenae) was studied by scanning electron microscopy using both critical point dried and frozen, fully hydrated specimens. Fully hydrated specimens were much closer to the natural state than those that had been critical-point dried. Several stages of fungal infection were observed that are similar to those reported for entomopathogenic fungi. Cereal cyst nematode eggs from white females or from cysts were examined before plating on agar. Eggs from both sources had two distinct shapes. This was caused by differences in the developmental stage of the eggs from white females and by the presence or absence of internal fungal material in eggs from cysts.