Fighting caterpillar pests and managing agricultural insecticide resistance with Lepidoptera-associated <i>Enterococcus casseliflavus</i>

Abstract

<p>Probiotics are live microorganisms that are intended to benefit the health of metazoan hosts. Mutualism in insects (both pests and beneficial insects) provides a vital contribution to host fitness. With the development and demand for healthy modern agriculture, bacterial symbionts are considered to be an important toolbox for pest control and beneficial insect protection. <i>Enterococcus casseliflavus</i> is a widespread symbiont in most Lepidoptera insect pests. Recent studies indicated that <i>E. casseliflavus</i> provides beneficial phenotypes to the host, including supplying a diet lacking amino acids and enhancing insecticide resistance. We propose that <i>E. casseliflavus</i> should have enormous biotechnological potential awaiting further exploitation for Lepidoptera insect pest control or beneficial insect protection through symbiont-targeted insecticide resistance management, because this symbiont is widespread in natural caterpillar hosts, easily isolatable and cultured, and rapidly spreadable within the caterpillar population. We outline the rationales for why <i>E. casseliflavus</i> is suitable for application in pest management and envision possible plans of symbiont-targeted therapeutics via four potential approaches: genome modification, phage engineering, predatory biocontrol, and synthetic microbiome. This perspective opens up a grand blueprint for the future of symbiont-targeted insect pest suppression or economic insect promotion.</p>