Can plants mediate the humoral immunity and biochemical metabolism of entomopathogen‐infected caterpillars?

Abstract

Plant‐insect herbivore‐entomopathogen interactions are one of the hot topics in biological control and humoral immunity, and biochemical metabolism are important responses of herbivores to pathogen infection. Entomopathogens are key biocontrol agents of caterpillars, but how plants affect the responses of caterpillars to these organisms is not well understood. We studied hormonal immunity (lysozyme and phenoloxidase activities) and biochemical metabolism (total protein and lipid contents) of Beauveria bassiana‐infected beet armyworm (Spodoptera exigua) larvae that feed on five different host plants (soya bean, Chinese cabbage, edible amaranth, water convolvulus and pepper). Results indicated that plant species differentially affected lysozyme and phenoloxidase activity and lipid content, but had no effect on protein content of pathogen‐infected caterpillars. Both lysozyme and phenoloxidase activities were generally higher in entomopathogen‐infected larvae that feed on edible amaranth or water convolvulus compared with the other three plants from days 1 to 5 after treatment. Plant species did not affect in regular changes during the 5 days in the lipid content of infected or non‐infected caterpillars. Our study reveals that plants fail to affect the biochemical metabolism but plants can mediate the humoral immunity of caterpillars to defend against pathogens. This study provides insight into plant‐mediated effects on the response of herbivores to pathogens.

Plant secondary metabolites impact the susceptibility of caterpillars to an entomovirus

“…Beet armyworm (Spodoptera exigua , Lepidoptera: Noctuidae) is a widely-distributed polyphagous herbivore (Wan et al, 2019a;Liao et al ., 2020) andSpodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) is an effective biocontrol agent of this pest (Jiang et al ., 2011;Virto et al ., 2017;Wan et al ., 2019b). In an earlier study, we found significant mortality differences among SeMNPV-infectedS.…”

Plant‐mediated effects on life history traits of entomovirus infected caterpillars ofSpodoptera exigua

“…Beet armyworm ( Spodoptera exigua, Lepidoptera: Noctuidae) is a polyphagous herbivore (Chen et al., 2020; Moulton et al., 2015; Wan, Zhou, et al., 2019). Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) is one of the most important biocontrol agents of S. exigua (Jiang et al., 2011; Virto et al., 2017; Wan, Yang, et al., 2019).…”