Adult dragonflies will eat any insect as long as they are able to catch it. While they usually eat mosquitoes and midges, they also eat butterflies, moths, beetles, bees, flies, and even other dragonflies. The general rule is that larger dragonflies will eat insects of body weight daily.
Origin of the name Viola: Derived from the Latin viola (a violet). The name has been in use since the Middle Ages but did not become common until the middle of the 19th century when the use of flower names came into vogue. From A World of Baby Names by Teresa Norman.
A viola (pronounced vee-Oh-la) is a musical instrument which is similar to the violin and cello. The viola sounds lower than a violin, but higher than a cello. It has four strings, called the C, G, D, and A strings. The highest string is the A. The viola is played with a bow in the right hand. Playing with the bow is called arco.