as host range and nature of fungal interaction
with the host (Humber 1989 ).
a) Basidiobolomycetes and Basidiobolales
The members of Basidiobolales are either sap-
robes or they can cause basidiomycoses in
humans. The vegetative mycelium is septate
and uninucleate [Fig.8.1(10)], or cells can be
produced that are yeastlike. Each nucleus is at
least 10mm long, but it can be longer, and the
nucleolus is prominent. The conidiophores are
not branched, and each bears a subsporangial
vesicle. Each conidium is uninucleate and pro-
duces a two-layered wall, but the layers are not
separable. The conidia are actively discharged
by a rocketlike mechanism upon the rupture of
a circumscissile weakening in the wall of a
turgid subconidial swelling. The mature rest-
ing spores [Fig.8.1(12), zygospores] have two
nuclei, one from each of the conjugating cells.
Basidiobolales was proposed (Cavalier-
Smith 1998 ) for members of the genusBasidio-
bolus. These fungi form a spindle-pole body
(SPB) (see McLaughlin et al. 2014 )ora
nucleus-associated organelle according to
McKerracher and Heath ( 1985 ). Each SPB is
composed of 11–12 singlet microtubules and
is a centriole, according to Cavalier-Smith
( 1998 ). The centrioles and kinetosomes of all
eukaryotes with flagella have microtubules
arranged in a 93 pattern. The SPB is not
part of a flagellum and, therefore, is not a cen-
triole, according to Humber (2012b).
These fungi form forcibly released conidia
and protuberances with terminal cells (Benja-
min 1962 ; Drechsler 1956 ). Early phylogenetic
studies (Jensen et al. 1998 ; Nagahama et al.
1995 ) indicated thatB. ranarumEidam is the
sister species toOlpidium brassicae(Woronin)
P.A. Dang.B. ranarumand other taxa in Basi-
diobolales are members of Entomophthoromy-
cota based on biology and the latest
phylogenetic studies (Gryganskyi et al. 2012 ,
2013 ; Humber2012b).
b) Entomophthoromycetes
and Entomophthorales s.s.
Vegetatively the members of Entomophthor-
ales sensu Humber (2012b) can produce
hyphal bodies (arthropod parasites) or coeno-
cytic mycelium (saprobic species ofConidio-
bolus) [Fig. 8.1(1)]. Simple or branched
conidiophores [Fig.8.1(4)] are produced that
bear an apical conidiogenous cell (Ancylista-
ceae, Completoriaceae, Entomophthoraceae),
or the fertile branch may be erect and septate,
and one propagule is produced by each cell
(Meristacraceae). The primary conidia are
either uni- or bitunicate [Fig.8.1(5–8)] and
are usually actively discharged by papillar
eversion. The secondary conidia, if formed,
can be either actively or passively discharged.
The interphase nuclear appearance varies
depending on the specific taxon examined.
The resting spores [Fig.8.1(13, 14)] can be
either zygospores or azygospores.i. Entomophthorales Sensu Humber (2012a)
and Four Families (Ancylistaceae, Completoriaceae,
Entomophthoraceae, Meristacraceae)
Many members of Entomophthoromycetes
(Entomophthorales sensu Humber2012b), or
Entomophthorales without the Basidiobolaceae
and Neozygitaceae of Humber ( 1989 ), are obli-
gate parasites of various animals (e.g., insects,
nematodes, mites). Conidiobolus is mainly
saprobic in soil, detritus, and dung, although
species in this genus may be pathogens of insects
or cause mycoses in humans or other mammals.
AncylistesandCompletoriaare parasites of des-
mid algae and fern prothallia, respectively. Spe-
cies ofMacrobiophthoraandMeristacrumare
parasites of nonarthropodous invertebrates
such as nematodes and tardigrades (Tucker
1981 ).Tabanomyces(Couch et al. 1979 )isa
member of Meristacraceae (Humber2012b).
Entomophthoralean pathogens (especially
Eryniaspp.) affecting insects in very wet envir-
onments, for example, ovipositing blackflies
(Diptera: Simuliidae), may become wetted dur-
ing the development of primary or secondary
conidia and then may produce “tetraradiate”
spores bearing several blunt branches. Such
spores are passively rather than actively dis-
persed (Descals and Webster 1984 ).
The members of Entomophthorales are best
known from temperate climates to the semiarid
tropics; these fungi are relatively little collected
in forests of the humid tropics (Evans 1982 ),Zygomycetous Fungi: Phylum Entomophthoromycota and Subphyla Kickxellomycotina,... 223