Elm Leafminer

What are they?

Small fly-like wasp that tends to feed on the lower and upper layers of the leaf. Eventually this feeding kills the leave and can affect the long term viability of elm tree. Most common on Red Elms.

What are the signs?

· Leaf drop

· Brown leaves with thin papery die back

Life Cycle

· Overwinter in the ground

· Adults mate and lay eggs in the leaf in spring

· Larvae eat the leaves and drop into the ground once they are mature

Treatment and Prevention

· Plant different tree varieties

· Systemic insecticide injections are very effective at controlling Elm Leafminer