Effects of three endophytic entomopathogens on sweet sorghum and on the larvae of the stalk borer Sesamia nonagrioides

Abstract

Various endophytic fungi of native plants and crops are important entomopathogens. The objective of this study was to investigate the entomopathogenic action of Beauveria bassiana (Balsamo) Vuillemin, Metarhizium robertsii (Metchnikoff) Sorokin, and Isaria fumosorosea (Wize) Brown & Smith (all Ascomycota: Hypocreales) against larvae of Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae) artificially introduced into Sorghum bicolor L. (Moench) (Poaceae) plants under natural environmental conditions. Sorghum bicolor is an economically important crop cultivated for grain, fiber, forage, and lately for biofuel, and S. nonagrioides is its main pest in Mediterranean areas. Young sorghum plants were inoculated with the entomopathogens by spraying in the field. Plant water status, chlorophyll concentration, photosynthesis, and transpiration were not affected. Thirty days after endophyte establishment, plants were infested with fourth instars of S. nonagrioides. The endophytes prevented 50–70% of larvae from entering stalks. Larval mortality was 70–100% and tunnel lengths were reduced by 60–87%. Larval infestation resulted in reduced electron transport capacity and net photosynthetic rate, which was ameliorated in the presence of I. fumosorosea and reversed by B. bassiana and M. robertsii. The growth of sorghum was unaffected in all treatments during the experimental period. Beauveria bassiana and M. robertsii can protect sweet sorghum from damage induced by S. nonagrioides under natural environmental conditions without affecting plant physiology and growth.

Colonization of Beauveria bassiana (Balsamo) Vuillemin strains in maize (Zea mays L.) and their efficacy against stem borer Chilo partellus (Swinhoe)

“…Reduction in larval population and reduced damage may be associated with endophytic colonization of B. bassiana. Similar results were reported with endophytic B. bassiana strains for European corn borer, Ostrinia nubilalis in maize (Bing and Lewis, 1991), Sesamia calamistis in maize (Cherry et al, 2004), Cosmopolites sordidus in banana (Akello et al, 2008), Sesamia nonagrioides in sorghum (Mantzoukas et al, 2015) and Helicoverpa armigera in tomato (Qayyum et al, 2015). It has been reported (Gurulingappa et al, 2011) that endophytic strains of B. bassiana might have produced certain secondary metabolites in the host plant with anti feeding properties and insecticidal activity against the pests leading to mortality/less activity of the pest.…”

Endophytic fungi Beauveria bassiana Balsamo accelerates growth of common bean (Phaeseolus vulgaris L.)

“…According to Tefera and Vidal (2009), spraying with conidial suspensions of B. bassiana was the best method for introducing the fungus into sorghum leaves. When a B. bassiana conidia solution was sprayed onto maize, the fungus colonized the leaves and translocated to other tissues (Wagner and Lewis 2000 in Mantzoukas et al 2015). Once hyphae on the leaf surface penetrate the cuticle, they follow the leaf apoplast and move through interconnected vascular tissues to colonize the entire plant (Mantzoukas et al 2015).…”

Invisible but consequential: root endophytic fungi have variable effects on belowground plant–insect interactions

“…, Mantzoukas et al. , also see references reviewed by Vidal and Jaber ). The majority of these studies revealed that endophytic B. bassiana reduces herbivore damage by a wide range of sucking, chewing, and tunneling insects in leaves and stems (Vidal and Jaber ).…”

“…In contrast, endophytic I. fumosorosea in sweet sorghum was found to greatly increase larval mortality of the stem borer Sesamia nonagrioides and reduce stem‐tunneling activities by 60–87% (Mantzoukas et al. ). Although M. alpina and F .…”