Aspergillus ustus is a very common species in foods, soil and
indoor environments. Based on chemical, molecular and morphological data,
A. insuetus is separated from A. ustus and revived. A.
insuetus differs from A. ustus in producing drimans and
ophiobolin G and H and not producing ustic acid and austocystins. The
molecular, physiological and morphological data also indicated that another
species, A. keveii sp. nov. is closely related but distinct
from A. insuetus. Aspergillus section Usti sensu
stricto includes 8 species: A. ustus, A. puniceus, A.
granulosus, A. pseudodeflectus, A. calidoustus, A. insuetus and
A. keveii together with Emericella heterothallica