"We found that a combination of physical and chemical defenses in corn plants can disrupt the protective gut barriers of fall armyworms, creating opportunities for gut microbes to invade their body cavities," said Charles Mason, postdoctoral scholar in entomology. "This can cause septicemia, which can kill the insect, or simply trigger an immune response, which can weaken the insect."

The researchers reared fall armyworms in the laboratory and inoculated them with one of three types of naturally occurring gut bacteria. They fed the insects on one of three types of maize—one that is known to express enzymes that produce perforations in insect gut linings; one that is characterized by numerous elongated trichomes, or fine hairs that occur on the surface of the plant and help defend against herbivores; and one that has just a few short trichomes. The team used scanning electron microscopy to evaluate the impacts of the various bacteria and maize types on the integrity of the fall armyworms' gut linings.

Read on: https://phys.org/news/2019-07-defend-insects-leaky-gut-syndrome.html