Multigene phylogeny, phylogenetic network, and morphological characterizations reveal four new arthropod-associated Simplicillium species and their evolutional relationship

Abstract

Simplicillium species are widely distributed and commonly found on various substrates. A minority of species are associated with arthropods. A spider-associated species Simplicillium araneae, and three insect-associated species, Simplicillium coleopterorum, Simplicillium guizhouense, and Simplicillium larvatum, are proposed as novel species based on a multi-locus phylogenetic analysis and morphological characteristics. These Simplicillium species completely fit the nutritional model of Hypocreales fungi and could be used as a model to study their evolutionary relationship. A phylogenetic network analysis based on ITS sequences suggests that a host jump was common among Simplicillium species, and S. araneae may have originally come from an insect host and then jumped to a spider host. However, the evolutionary relationship of S. coleopterorum, S. guizhouense, and S. larvatum was not clear in the phylogenetic network and more sequencing information should be added to the network. In addition, strain CBS 101267 was identified as Simplicillium subtropicum.

Defensive fungal symbiosis on insect hindlegs

“…We also performed amplicon sequencing analysis of the fungal ITS region using the DNA samples extracted from the hind tibiae and the eggs (Table S2). Molecular phylogenetic analyses based on these sequen ce data consistently revealed that (i) the majority of the fungi were placed within the class Sordariomycetes of the Ascomycota, (ii) the majority were classified to the family Cordycipitaceae mainly consisting of entomopathogenic fungi such as Cordyceps , Beauveria and others (10,11), and (iii) the majority represented several specific fungal lineages such as Lecanicillium , Simplicillium and Akanthomyces (12–14) (Figs. S4 and S5; Note S1).…”

“…S9c, d). These results suggest that adult females of M. gracilicorne preferentially pick up relatively benign entomopathogens, Simplicillium or Lecanicillium (12–14,25,26), from environmental sources and selectively maintain them on the hindleg organ (Note S3).…”

“…S5) have been mainly isolated from insects and fungi, and utilized as biological control agents for whiteflies, aphids, powdery mildews, etc. (12–14,25,26). It seems plausible that adult females of M. gracilicorne selectively establish association with the non-pathogenic fungi like Lecanicillium and Simplicillium on the hindleg organ, which entail occasional acquisitions of closely-related pathogenic fungi Akanthomyces , but the insects are resistant to them as long as the fungi are externally associated outside the thick cuticle.…”

Study on species diversity of Akanthomyces (Cordycipitaceae, Hypocreales) in the Jinyun Mountains, Chongqing, China

“…The hosts of Akanthomyces species cover Hemiptera , Coleoptera , Lepidoptera , Orthoptera and Araneae ( Hodge 2003 ; Mongkolsamrit et al 2018 ; Chen et al 2020b , 2022c). Chen et al (2022b) noted that a host jump may be common in Simplicillium species, the spider-associated species may have originated from insects and then jumped to a spider host. An abundant diversity in insects and spiders has been discovered at Jinyun Mountain ( Huang and Zhang 1991 ; Li et al 2009a , 2009b ; Wang et al 2012 ; Huang et al 2021 ; Yan et al 2021 ).…”

First Description of Simplicillium lanosoniveum, a Potential Antagonist of the Coffee Leaf Rust from Cuba

“…However, based on multi-gene phylogenetic analyses, Simplicillium was shown to belong to the family Cordycipitaceae (Hypocreales, Hypocreomycetidae, Sordariomycetes) [14][15][16]. Within the genus Simplicillium, species have been delineated mainly by means of ribosomal RNA operon sequence analyses [17,18].…”