Are flies vermin? Velikovsky accused this humble insect of being vermin and in the right circumstances they are – blue bottles especially. However, they also have a more beneficial role in human affairs – it is being suggested they are major pollinators of food crops. See http://phys.org/print346483658.html
Pollinators of renown include the bee, hoverflies, and butterflies. Ordinary flies have always been excluded as unimportant pollinators. Not true. Most flies, and not just the hoverflies, are notable pollinators. Hence, the panic over bee decline may be overblown (pun intended).