Evolutionary Arms Race Between Plant-Eating Insects and Host Plants Illuminated

From Science Daily:

Scientists trying to get a grip on the arms race between plant-eating insects and the defenses put up by their hosts just got a boost from new research by a University of Arizona entomologist published in the early view edition of Molecular Ecology.

Noah Whiteman, an assistant professor in the UA's department of ecology and evolutionary biology, has found a miniature ecosystem consisting of a plant and a tiny fly that spends its entire life cycle on the plant.

What makes this system special is the fact that both its key players — the plant and the insect — are what scientists call genetically tractable model organisms: holy grails of any serious science that aim to unravel biological mechanisms down to the level of genes and proteins and signaling molecules.

Decades of research and knowledge rest upon two of the most famous and widely used workhorses in genetics research: Arabidopsis thaliana, an unassuming, weedy plant in the mustard family, and Drosophila melanogaster, familiar to many as the tiny, red-eyed fruit flies hovering around the produce aisle.

However, until now, scientists wanting to study interactions between plant-eating insects and the plants they befell were out of luck: Fruit flies, as the name implies, feed on rotting fruit and couldn't care less about Arabidopsis plants, and vice versa.

Enter Scaptomyza flava, a fly so closely related to Drosophila melanogaster it shares most of its genes, and with a strong appetite for Arabidopsis. Female Scaptomyza flies prick a hole into the plant tissue and lay their eggs inside. Once the larvae hatch, they spend their childhood as leaf miners: tunneling their way through the leaf, munching on the nutritious plant tissue.

More here.