Direct and Indirect Effect via Endophytism of Entomopathogenic Fungi on the Fitness of Myzus persicae and Its Ability to Spread PLRV on Tobacco

Abstract

Aphids are major crop pests that transmit more than half of all insect-vectored plant viruses responsible for high yield losses worldwide. Entomopathogenic fungi (EPF) are biological control agents mainly used by foliar application to control herbivores, including sap-sucking pests such as aphids. Their ability to colonize plant tissues and to interact with diverse plant pathogenic microorganisms have been reported. In our study, we evaluated the effectiveness of Beauveria bassiana ((Balsamo-Crivelli) Vuillemin) directly applied by contact or/and indirectly via endophytism in tobacco plants (Nicotiana tabacum L.) against the virus vector Myzus persicae (Sulzer) carrying the Potato leafroll virus (PLRV) or not. We found that both contact treatment and endophytic colonization of leaves significantly increased aphid mortality and decreased the fecundity rate when compared to control plants. In addition, on fungal-colonized leaves, viruliferous aphids were more negatively impacted than virus-free ones and nymph mortality was significantly higher than on fungal-free plants. Furthermore, we assessed PLRV transmission by M. persicae on tobacco plants inoculated with either B. bassiana or Metarhizium acridum ((Driver and Milner) JF Bischoff, Rehner, and Humber) as source or/and recipient plants. Myzus persicae was found to acquire and transmit PLRV regardless of the treatment. Nevertheless, the infection rate of endophytically colonized plants was lower at a seven-day incubation period and had increased to almost 100% after fifteen days. These results suggest that B. bassiana is effective against aphids, both by contact and via endophytism, and both B. bassiana and M. acridum delayed PLRV infection in tobacco.

Establishment of Beauveria bassiana as a fungal endophyte in potato plants and its virulence against potato tuber moth, Phthorimaea operculella (Lepidoptera: Gelechiidae)

“…B. bassiana‐ colonized tobacco increases resistance to aphids ( Myzus persicae ) (Qin et al ., 2020). B. bassiana is effective against aphids via endophytism and delays potato leafroll virus infection in tobacco (Fingu‐Mabola et al ., 2021).…”

Entomopathogenic fungus disrupts the phloem-probing behavior of Diaphorina citri and may be an important biological control tool in citrus

“…Others have evaluated the effects of traditional insecticides on vector probing behavior, with implications for the transmission of phytopathogens 10 , 30 – 32 . However, very few have investigated the effects of entomopathogenic fungi on the probing behavior of insect vectors before they are killed by the fungi 33 – 35 . These studies provide essential information for managing phytopathogens and their vectors since disruptions in stylet activities can affect the efficiency of transmission of pathogens to new host plants via vector feeding.…”

Biological Pests Management for Sustainable Agriculture: Understanding the Influence of Cladosporium-Bioformulated Endophytic Fungi Application to Control Myzus persicae (Sulzer, 1776) in Potato (Solanum tuberosum L.)

“…The application of ecologically-reassuring biopesticides may be considered as an alternative or integrative to chemical control [ 14 , 15 ]. The effects of endophytic fungi as biocontrol agents against aphids were recently experienced on some crop plants [ 16 , 17 , 18 , 19 , 20 , 21 ].…”