The Large Dark Olive
One of the first flies to show on the river in any numbers and an important food source for both trout and grayling.
All the photographs sen below show both male and female insects at differing times of their life cycle and were recorded on the River Usk between 1960 and 1986.
It scientific name is Baetis Rhondani. By its initial categorization, of being a baetis it infers that the nymph is an ‘agile darter’ and free swimming as opposed to a stone clinger.
Large Dark Olive Nymph
Large Dark Olive Male Dun
Large Dark Olive Male Dun (from another angle)
Large Dark Olive Female Dun.
Large Dark Olive Female Dun (from another angle)
Large Dark Olive Male Spinner
Large Dark Olive Female Spinner
The main identification of the male from the female are the forceps of the male that are normally just under the base of its tail
The Lard Dark Olive Male Forceps
These forceps can be seen on both the dun and the spinners.