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The entomophthoralean fungusZoophthora rhagonycharum(Bałazy) S. Keller, previously recorded in Europe from Poland and Switzerland, is now reported in North America from New York State, United States of America. On both continents, this obligate insect pathogen is known only from resting spores found within dead, adult native soldier beetles (Cantharidae) of the genusRhagonychaEschscholtz, 1830. Resting spores have undulating, light brown episporia. In New York, columnar rhizoids attach cadavers tightly to the undersides of leaves in the understory of hardwood forests in late June and early July. 

Despite over a century of observations, the obligate insect parasites within the order Entomophthorales remain poorly characterized at the genetic level. In this manuscript, we present a genome for a laboratory-tractableEntomophthora muscaeisolate that infects fruit flies. OurE. muscaeassembly is 1.03 Gb, consists of 7810 contigs and contains 81.3% complete fungal BUSCOs. Using a comparative approach with recent datasets from entomophthoralean fungi, we show that giant genomes are the norm within Entomophthoraceae owing to extensive, but not recent, Ty3 retrotransposon activity. In addition, we find thatE. muscaeand its closest allies possess genes that are likely homologs to the blue-light sensorwhite-collar 1, aNeurospora crassagene that has a well-established role in maintaining circadian rhythms. We uncover evidence thatE. muscaediverged from other entomophthoralean fungi by expansion of existing families, rather than loss of particular domains, and possesses a potentially unique suite of secreted catabolic enzymes, consistent withE. muscae’s species-specific, biotrophic lifestyle. Finally, we offer a head-to-head comparison of morphological and molecular data for species within theE. muscaespecies complex that support the need for taxonomic revision within this group. Altogether, we provide a genetic and molecular foundation that we hope will provide a platform for the continued study of the unique biology of entomophthoralean fungi. 

Fungi of the Conidiobolus group belong to the family Ancylistaceae (Entomophthorales, Entomophthoromycotina, Zoopagomycota) and include over 70 predominantly saprotrophic species in four similar and closely related genera, that were separated phylogenetically recently. Entomopathogenic fungi of the genus Batkoa are very close morphologically to the Conidiobolus species. Their thalli share similar morphology, and they produce ballistic conidia like closely related entomopathogenic Entomophthoraceae. Ballistic conidia are traditionally considered as an efficient tool in the pathogenic process and an important adaptation to the parasitic lifestyle. Our study aims to reconstruct the phylogeny of this fungal group using molecular and genomic data, ancestral lifestyle and morphological features of the conidiobolus-like group and the direction of their evolution. Based on phylogenetic analysis, some species previously in the family Conidiobolaceae are placed in the new families Capillidiaceae and Neoconidiobolaceae, which each include one genus, and the Conidiobolaceae now includes three genera. Intermediate between the conidiobolus-like groups and Entomophthoraceae, species in the distinct Batkoa clade now belong in the family Batkoaceae. Parasitism evolved several times in the Conidiobolus group and Ancestral State Reconstruction suggests that the evolution of ballistic conidia preceded the evolution of the parasitic lifestyle.