New research reveals that Aspergillus flavus, a fungus that produces carcinogenic aflatoxins that can contaminate seeds and nuts, has a multilegged partner in crime: the navel orangeworm caterpillar, which targets some of the same nut and fruit orchards afflicted by the fungus. Scientists report that the two pests work in concert to overcome plant defenses and resist pesticides.
"It turns out that the caterpillar grows better with the fungus; the fungus grows better with the caterpillar," said University of Illinois entomology professor and department head May Berenbaum.
Prior to the new study, researchers and growers had observed coinfection with the fungus and the caterpillar, but did not know whether the two simply tolerated one another or worked together in a mutualistic partnership. To find out, the team ran experiments to see how laboratory-reared navel orangeworm caterpillars responded to specific plant defensive compounds and pesticides in the presence or absence of the fungus.
The tests revealed that the caterpillars developed much more rapidly in the presence of the fungus, regardless of the natural or human-made toxins that were also present.
Read more about this study at Science Daily.