Since the headline is somewhat click-baity, the answer to "here's what it tells us": Caterpillars, dragonflies, certain ants and other animals provide a way to

Since the headline is somewhat click-baity, the answer to "here's what it tells us": Caterpillars, dragonflies, certain ants and other animals provide a way to investigate the potential disadvantages of long-lasting symbiotic relationships with live-in microbes; such disadvantages tend to be difficult to measure and test. A microbiome might theoretically enable the caterpillars to manufacture additional important nutrients or go after more nutrient-dense vegetation, but the insects can make up for quality with quantity.