Tilletia caries is a plant pathogen that infects wheat causing the disease bunt. Plants infected with the disease are often slightly stunted, occasionally with yellow streaks on the flag leaf. Grain is replaced with bunt balls containing masses of black spores. At ripening, the ears take longer to lose their green colour, are short and plump and the glumes are pushed further apart. The spores of bunt have a strong fish-like smell. Infection occurs at harvest or during grain handling when the spores are spread to healthy seed.