When black locusts bloom in the Twin Cities it means that the adults of our most destructive tree borers are currently emerging from infested trees. Emerald ash borer, bronze birch borer and two lined chestnut borer adults are now spreading from ash, birch and oak trees, respectively. The beetles will find mates and begin laying eggs in new trees within the next few weeks.
White bark birches, oaks and ash are all susceptible to the larvae of these beetles. Dieback from the tips of the branches are indicative of active bronze birch borer and two-lined chestnut borer infestations. Treatments should be applied to the trees to kill new larvae before they have the chance to damage the water and nutrient transportation system of the tree.