Filamentous fungi of the genera Lecanicillium and Akanthomyces (Ascomycota: Hypocreales: Cordycipitaceae) have been isolated from a variety of insect orders and are of particular interest as biological control agents for phloem-sucking plant pests. Three aphid- and whitefly-pathogenic fungal strains that had been isolated from naturally infected Trialeurodes vaporariorum and Myzus persicae in Argentina were assigned to the species Lecanicillium uredinophilum by combined analyses of morphology and ITS, LSU, EF1A, RPB1 and RPB2-based molecular taxonomy, giving rise to both the first description of this fungus from hemipteran insects and its first report from outside South-East Asia, especially from the American continent. A combination of phylogenetic reconstruction and analysis of pair-wise sequence similarities demonstrated that—reflecting recent changes in the systematics of Cordycipitaceae—the entire species L. uredinophilum should be transferred to the genus Akanthomyces. Consequently, the introduction of a new taxon, Akanthomaces uredinophilus comb. nov., was proposed. Moreover, extensive data mining for cryptic A. uredinophilus sequences revealed that (i) the fungus is geographically widely distributed, including earlier unrecognized isolations from further American countries such as the USA, Mexico, and Colombia, and (ii) entomopathogenic and mycoparasitic lifestyles are predominant in this species.

(1) Background: The entomopathogenic fungus Metarhizium anisopliae sensu lato forms a species complex, comprising a tight cluster made up of four species, namely M. anisopliae sensu stricto, M. pinghaense, M. robertsii and M. brunneum. Unambiguous species delineation within this “PARB clade” that enables both the taxonomic assignment of new isolates and the identification of potentially new species is highly solicited. (2) Methods: Species-discriminating primer pairs targeting the ribosomal intergenic spacer (rIGS) sequence were designed and a diagnostic PCR protocol established. A partial rIGS sequence, referred to as rIGS-ID800, was introduced as a molecular taxonomic marker for PARB species delineation. (3) Results: PARB species from a validation strain set not implied in primer design were clearly discriminated using the diagnostic PCR protocol developed. Using rIGS-ID800 as a single sequence taxonomic marker gave rise to a higher resolution and statistically better supported delineation of PARB clade species. (4) Conclusions: Reliable species discrimination within the Metarhizium PARB clade is possible through both sequencing-independent diagnostic PCR and sequencing-dependent single marker comparison, both based on the rIGS marker.

The aim of this study was to investigate biological and molecular characteristics of Lecanicillium strains isolated from Hemipteran hosts in Argentina. Morphology‐based taxonomic characterization together with molecular taxonomy based on rRNA operon internal transcribed spacer (ITS), mitochondrial nad1 gene, and nuclear ef1a gene sequences resulted in the assignment of nine out of ten isolates to the Lecanicillium lecanii sensu lato complex. However, whereas several isolates were thus unequivocally characterized as Lecanicillium muscarium or Lecanicillium longisporum, species assignment was not possible for three isolates that might represent a new species within the L. lecanii s.l. complex. We found two group‐I introns on 18S and 28S rRNA gene on only one isolate. Pathogenicity tests were conducted against the peach aphid using conidial suspensions (1 × 10⁷ conidia/ml), and the Kaplan–Meier analysis was performed to evaluate the survival of Myzus persicae. Lecanicillium longisporum CEP 155 and L. muscarium CEP 182 were significantly more pathogenic to M. persicae than all the Lecanicillium isolates causing aphid mortalities >85%. Determination of susceptibility to the benzimidazole fungicide benomyl revealed important differences between Lecanicillium strains. The inhibitory effect of benomyl appeared less pronounced for the L. muscarium fungal isolates than for those belonging to a different taxon. Based in our results, the best candidate strain as microbial biological control agent against M. persicae is L. muscarium CEP 182. However, further research under field conditions in greenhouses should be done in order to confirm the compatibility of entomopathogenic fungi and fungicides within an IPM strategy.

The aim of this study was to identify entomopathogenic fungi infecting spiders (Araneae) in a protected area of Buenos Aires province, Argentina. The Araneae species identified was Stenoterommata platensis. The pathogens identified were Lecanicillium aphanocladii Zare & W. Gams, Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel Jones & Samson and Ophiocordyceps caloceroides (Berk & M.A. Curtis). This study constitutes the southernmost records in the world and contributes to expanding the knowledge of the biodiversity of pathogenic fungi of spiders in Argentina.

(1) The fungal genus Simplicillium (Cordycipitaceae: Hypocreales) has an extensive distribution and a broad spectrum of hosts and substrates. The species Simplicillium lanosoniveum is a mycoparasite with potential for biological control of coffee leaf rust, Hemileia vastatrix. Morphologically, Simplicillium closely resembles mycoparasitic and entomopathogenic Lecanicillium fungi, often resulting in misidentification. A fungal isolate was obtained from leaf-rust-infested coffee plants from Cienfuegos Province, Cuba. (2) Combined analyses of morphology and molecular markers (ITS, LSU, EF-1alpha) were used for fungal identification. (3) In the NJ, ML, and BI phylogenies which were reconstructed, the isolate LBSim-01 was located in the Simplicillium lanosoniveum clade. This species-level identification was supported by morphological features. (4) The isolate LBSim-01 was assigned to the species Simplicillium lanosoniveum. This is the first description of a Simplicillium fungus associated with coffee leaf rust in Cuba. The presented results hold implications for the biological control of this economically relevant plant disease.