Mayfly Species Drunella lata (Small Blue-Winged Olive)

When Selective Trout was first published in 1971, Swisher and Richards included Drunella lata (Small Blue-Winged Olive, Slate-Winged Olive) as a Midwestern "superhatch." Although it can also be found in many Eastern trout streams, it is probably more important to Midwestern anglers. Typically a morning emerger, this species often competes for the attention of trout with more abundant Tricorythodes and small baetids during parts of July and August. For this reason, the authors of Selective Trout considered the concentrated evening spinner falls to be more important than the somewhat sporadic morning emergence. From an angling standpoint, this situation is nearly the opposite of the earlier Drunella cornuta emergence in the East, where the morning emergence is usually the main event and spinner falls are often of little consequence.

Currently, Drunella lata shares its name with another mayfly, the former D. longicornis. That mayfly can be important in mountainous areas in the Southeast, but they are larger and the nymphs lack the distinctive pale markings mentioned in the Juvenile Characteristics section. (The information on this page does not describe D. longicornis)