ENTM 295 N Insect Pests of Trees Turf and Ornamentals�
Lecture 20. Insect Trunk and Limb Borers
Which trees are likely to get borers?
- Healthy trees tend to be well defended against borers.
- Trees under water stress are less capable of defending themselves.
- Site conditions (transplant shock, or paving) that promote root problems tend to promote borer problems
- Trees stressed by repeated defoliation are also less well defended against �� borers.
How can sanitation reduce problems with borers?
- Many borers winter in dying or recently killed trees.
- Removing these trees can greatly reduce the source of borers in the landscape.
- Recognize that half dead trees seldom recover.� The last sign of death of a conifer,� brown needles, often occurs long after a tree is dead. ����
Chemical control of borers -
- Best results are achieved in combination with sanitation and good cultureal practices.
- Apply long-lasting topical insecticide (Resmethrin, bifenthrin,) to kill the borers as they chew their way out of the tree or chew their way in. ��Knowing the biology of each borer will help you best time the chemical application.
Use resistant varieties when available, in combination with cultural control
Kinds of� Borers:
Moths-��
����� Zimmerman pine moth
����� Clearwing borers- use of pheromone traps to time control.
����������� Dogwood borer
����������� Ash-lilac borer
����������� Peach tree borer
����������� Rhododendron borer
����� Root collar borer Euzophora spp.
Beetles-
����� Metallic wood boring beetles
����������� Bronze birch borer
����������� Flat headed apple tree borer
������ Roundheaded borers
����������� Black locust borer
����������� Asian longhorned beetle
����������� Pine sawyer beetles (Also will vector disease)
������ Weevils
����������� Pales and Northern pine weevil (importance of cut-over pine)
����������� Pine root collar weevil