Abstract:
The invasive tomato leaf miner, Phthorimaea absoluta, is conventionally controlled
through chemical insecticides. However, the rise of insecticide resistance has necessitated sustainable and eco-friendly alternatives. Entomopathogenic
fungi (EPF) have shown potential due to their ability to overcome resistance
and have minimal impact on non-target organisms. Despite this potential, the
precise physiological mechanisms by which EPF acts on insect pests remain
poorly understood. To attain a comprehensive understanding of the complex
physiological processes that drive the successful control of P. absoluta adults
through EPF, we investigated the impacts of different Metarhizium anisopliae
isolates (ICIPE 665, ICIPE 20, ICIPE 18) on the pest’s survival, cellular immune
responses, and gut microbiota under varying temperatures. The study unveiled
that ICIPE 18 caused the highest mortality rate among P. absoluta moths, while
ICIPE 20 exhibited the highest significant reduction in total hemocyte counts
after 10 days at 25°C. Moreover, both isolates elicited notable shifts in P. absoluta’s
gut microbiota. Our findings revealed that ICIPE 18 and ICIPE 20 compromised
the pest’s defense and physiological functions, demonstrating their potential as
biocontrol agents against P. absoluta in tomato production systems.
