Why insects stop 'breathing' | Science Blog:
A new study investigating the respiratory system of insects may have solved a mystery that has intrigued physiologists for decades: why insects routinely stop breathing for minutes at a time. Challenging previous theories, researchers at UC Irvine and Humboldt University propose that insects such as grasshoppers, moths, butterflies, some types of fruit flies, beetles and bugs close off their respiratory systems periodically to keep out excess oxygen, thus preventing damage to their tissues.
Why those families? Phylogenetics, baby. That's right, we're talking shared, derived characters, common descent, and evolutionary adaptations to powerful flight. We're also talking about the common descent of the most diverse group of animals. Not to be taken lightly.