A monograph of the entomopathogenic genera Hypocrella, Moelleriella, and Samuelsia gen. nov. (Ascomycota, Hypocreales, Clavicipitaceae), and their aschersonia-like anamorphs in the Neotropics

Abstract

The present taxonomic revision deals with Neotropical species of three entomopathogenic genera that were once included in Hypocrella s. l.: Hypocrella s. str. (anamorph Aschersonia), Moelleriella (anamorph aschersonia-like), and Samuelsia gen. nov (anamorph aschersonia-like). Species of Hypocrella, Moelleriella, and Samuelsia are pathogens of scale insects (Coccidae and Lecaniidae, Homoptera) and whiteflies (Aleyrodidae, Homoptera) and are common in tropical regions. Phylogenetic analyses of DNA sequences from nuclear ribosomal large subunit (28S), translation elongation factor 1-α (TEF 1-α), and RNA polymerase II subunit 1 (RPB1) and analyses of multiple morphological characters demonstrate that the three segregated genera can be distinguished by the disarticulation of the ascospores and shape and size of conidia. Moelleriella has filiform multi-septate ascospores that disarticulate at the septa within the ascus and aschersonia-like anamorphs with fusoid conidia. Hypocrella s. str. has filiform to long-fusiform ascospores that do not disarticulate and Aschersonia s. str. anamorphs with fusoid conidia. The new genus proposed here, Samuelsia, has filiform to long-fusiform ascospores that do not disarticulate and aschersonia-like anamorphs with small allantoid conidia. In addition, the present study presents and discusses the evolution of species, morphology, and ecology in Hypocrella, Moelleriella, and Samuelsia based on multigene phylogenetic analyses.

Polycephalomyces agaricus, a new hyperparasite of Ophiocordyceps sp. infecting melolonthid larvae in southwestern China

“…The phylogenetic classification of Hypocreales has been rapidly developing with the application of multi-locus phylogenies (Sung et al 2007;Chaverri et al 2008;Quandt et al 2014). Recently, the most complete taxonomic treatment of Polycephalomyces was conducted using the 5-locus phylogeny (Kepler et al 2013).…”

Current nomenclatural changes inCordyceps sensu latoand its multidisciplinary impacts

“…Hodge and Samuelsia P. Chaverri & K.T. Hodge are placed in this family (Sung et al 2007; Chaverri et al 2008; Johnson et al 2009) (Table 1). All of them are parasitic on scale insects or white flies.…”

“…(Johnson et al 2009). Other four genera Hypocrella, Moelleriella, Regiocrella and Samuelsia are linked to Aschersonia or Aschersonia -like anamorphs (Chaverri et al 2005a, 2008). …”

High genetic variation among Aschersonia placenta (Clavicipitaceae) isolates from citrus orchards in China

“…Entomopathogenic fungi of the genus Aschersonia are found growing on whiteflies and scale insects, and are common in tropical regions, particularly in moist old-growth forests and citrus orchards (Chaverri et al, 2008). Species in Aschersonia, such as A. aleyrodis and A. placenta, invade their hosts by actively penetrating the cuticle and have been recognized as an important fungal pathogen of whiteflies (Fransen et al, 1987;Faria and Wraight, 2001;Charnley and Collins, 2007).…”

“…Random amplified polymorphic DNA (RAPD) markers have been used to investigate relationships between Aschersonia species and isolates (Oborník et al, 1999). In recent years, molecular phylogenetic analyses based on some genetic loci, such as large subunit nuclear ribosomal DNA (LSU), translation elongation factor 1-α (TEF1-α), RNA polymerase II subunit 1 (RPB1), RNA polymerase unit II (RPB2), mitochondrial small subunit rDNA (mtSSU), β-tubulin and internal transcribed spacer (ITS) sequences, were conducted to determine the relationships of new species to other species of Hypocrella/Aschersonia (Chaverri et al, 2005;Torres et al, 2007;Mongkolsamrit et al, 2009) and to examine whether some techniques were helpful in the classification of species with morphological characters (Liu et al, 2006;Chaverri et al, 2008). Although the phylogeny of A. placenta has been studied by a few researchers, the genetic diversity and population structure of A. placenta remain unknown.…”