Yellowstone Park, August 24th, 2024

Tricos make for the biggest mayfly activity on many park streams these days. PMDs are decreasing as we move towards fall.  Speckled duns populate some still waters including Beula and Trout Lakes. However other mayfly species will become active. One is hecuba timpanoga also known as the “Drake Mackerel” or red quill. Hecuba can also be mistaken for the green drake. Mahogany duns are another species that will become active on park streams and are more widespread than hecuba. Even more widespread will be the fall emergence peak of the BWO. Meanwhile, terrestrial insects are a major reason for the great top water fishing most park streams offer this time of the season and will continue to be such until a killing frost arrives..