Fungi are commonly associated with arthropods in a variety of habitats
. Many species of ascomycetes have morphological features, including e
vanescent asci and passively discharged ascospores, that facilitate as
cospore dispersal by arthropods. Based on small subunit ribosomal DNA
sequence analysis several lineages appear to have been derived indepen
dently by convergence. One monophyletic lineage includes Pyxidiophora
and Rickia (Laboulbeniales). Evolution of Laboulbeniales from a Pyxidi
ophora-like ancestor is viewed perhaps as life cycle simplification to
reduce excessive fine-tuning of the life cycle to two disparate hosts
and to reduce habitat patchiness. The minute arthropod-borne fungi, T
haxteriola, Endosporella, Laboulbeniopsis, Coreomycetopsis, Amphoropsi
s, Myriopodophila, and Entomocosma, are included in the Pyxidiophora-R
ickia lineage as part of the Pyxidiophora life cycle or as independent
organisms on the basis of morphology and life history studies.