Damselflies are an important food source to trout, they are abundant in many waterways throughout North America. These flies are available from spring to the end of the season, darker shades should be used in the early season moving to lighter smaller variations at the end of the season. An erratic retrieve works well with this pattern it is important to implement some movement to stimulate the take. The Damselfly Nymph can also be fished static imitating a resting Nymph, I have found this to be extremely productive.