Investigating the Impact of Beneficial Microorganisms Inoculated Cotton Plants on Spodoptera exigua

Abstract This study discusses the knowledge obtained about the plant-mediated effects of beneficial soil-borne microorganisms on survival rates, development, reproduction, and population growth parameters of Spodoptera exigua, a major cotton pest. Specifically, we examined how beneficial microorganisms impact the oxidative stress, chlorophyll content, sugar and protein levels within the cotton plant and subsequently influence the pest's population growth performance. We also evaluated the reciprocal effects of plant-insect-microorganisms interaction on total glutathione levels, glutathione S-transferase and esterase enzyme activities in S. exigua. The findings of this study revealed that there was no evidence of oxidative stress in the treated plants. However, the treated plants exhibited enhanced chlorophyll content while demonstrating reduced levels of Protein/Carbohydrate, consequently leading to a discernible decrease in the population growth performance of S. exigua. These results highlight the intricate interplay between oxidative stress, chlorophyll content, and nutritional composition, which collectively influence the population dynamics and performance of the treated plants. The concept of "host plant quality" which encompasses characteristics like nitrogen and carbon content, trace elements, and defence chemicals, played a crucial role in shaping the success of S. exigua. Changes in plant characteristics and nutrient balance can affect the performance of insects, even if they consume more leaves, leading to an increase in midgut tissue weight in S. exigua larvae. Consequently, this decrease in pest numbers is expected to enhance the plant's ability to withstand damage. Additionally, the findings from this study provided valuable insights and pertinent information regarding the intricate three-way interactions among plants, microorganisms, and pests, thereby offering potential strategies for implementing these interactions in pest management practices.