**Rosario Nicoletti 1,2,\* and Andrea Becchimanzi <sup>2</sup>**


Received: 11 May 2020; Accepted: 5 June 2020; Published: 6 June 2020

**Abstract:** The rise of the holobiont concept confers a prominent importance to the endophytic associates of plants, particularly to species known to be able to exert a mutualistic role as defensive or growth-promoting agents. The finding that many entomopathogenic fungi are harbored within plant tissues and possess bioactive properties going beyond a merely anti-insectan effect has recently prompted a widespread investigational activity concerning their occurrence and functions in crops, in the aim of an applicative exploitation conforming to the paradigm of sustainable agriculture. The related aspects particularly referring to species of *Lecanicillium* and *Akanthomyces*(Sordariomycetes, Cordycipitaceae) are revised in this paper, also in light of recent and ongoing taxonomic reassessments.

**Keywords:** entomopathogens; endophytic fungi; crop protection; plant growth promotion; integrated pest management; bioactive compounds; Cordycipitaceae
