Tree Integrated Pest Management Dan Nortman Virginia Cooperative Extension, York County
IPM Refresher Definition: The use of a combination of appropriate pest control tactics to reduce pest population and their damage to an acceptable level. Based on sound scientific principles and research based information. Combination of controls Biological Cultural Chemical
RULES TO CHOOSING A PEST CONTROL? 1. Control a pest when it is causing or expected to cause more damage than is reasonable. 2. Use a control strategy that will reduce the pest numbers to an acceptable level. 3. Cause as little harm as possible to everything, except the pest.
USING IPM TO SOLVE A PEST 1. Recognize the problem PROBLEM 2. Identify the pest or pests and determine whether a control is warranted for each condition 3. Determine your pest control goal(s) 4. Learn what control tactics are available 5. Evaluate the benefits and risks of each tactic or combination of tactics 6. Choose the strategy that will be most effective vs. environmental cost 7. If you use chemical controls, follow the label directions for use and storage of pesticide....the label is the law
Landscape IPM principles 1. A plant in a landscape is part of an ecosystem, therefore a landscape should be designed to: Resemble natural biodiversity Augment natural pest controls
Landscape IPM principles 2. When should a pest control action be taken? What is the pest? How many are there? How is the plant s health otherwise?
vs.
Landscape IPM principles 3. What options do I have? Biological Cultural Physical/ mechanical Chemical
Monitoring Signs vs. Symptoms Signs: Physical evidence that the pest is present Frass Spores Bacterial ooze Symptoms: Plant issues that may or may not be pest related Wilted leaves Defoliation Abnormal bark shedding
Signs
Symptoms
Common Symptoms in Trees Leaf Chlorosis Leaf Necrosis Wilting Defoliation Dieback Epicormic Shoots Decline
Leaf Chlorosis Possible Causes Depends on type & plant Interveinal Soil nutrients ph Herbicide damage Mottling Virus Nutrient issues Insects Fungi Stippling/ bronzing Mites Insects Disease
Leaf Necrosis/ Scorch Pattern on leaf Marginal Spot Entire leaf Damage on whole plant New growth Older foliage Entire canopy Selected branches Most commonly environmental condition or a nutrient issue Could be nematodes, insects and/ or disease
Wilting Many causes Too wet Too dry Salinity Diseases Root loss Insect feeding Know what issues can affect problem plant
Defoliation Numerous causes Herbicide stress Climactic Severity, season and length of time defoliation takes all matter
Dieback Death of twigs from tips downward Caused by: Disease Climate Poor drainage Insects
Epicormic shoots Often sign that plant is dying Girdling insects Old age Excessive pruning
Decline Kind of a catch all Dieback Little to no vigor Epicormic shooting Chlorosis Usually a combination of factors Disease Old age Climate change
General for Symptoms Know: Plant parts affected Pattern on parts and plant as a whole General problems for plant Climactic conditions Rate of onset What else is happening? Lots of diagnostic services through Virginia Tech, but they will ask many of these questions
Control Options Host Resistance The ability of a plant or animal to resist an attack by a pest Biological Use of natural enemies, parasites, predators, and pathogens. Cultural Altering the environment, the condition of the host plant or animal or the behavior of the pest to prevent or suppress an infection. This is during the growth period of a plant. Mechanical Removal of a pest from the host through the use of physical controls, traps, devices, and other objects. Chemical To destroy pests, control their activities or prevent them from causing damage.
Host Resistance Proper selection before planting Replace problem prone plants Resistance can be attributed to: Toxic compounds (physiological) Mechanical factors (bark, thick leaf cuticle) Host tolerance of damage Pests can overcome some types of resistance
Biological Control Conservation Providing environment Choosing pesticides carefully Augmentation Release of predators or parasitoids Formulated products Entomopathogenic nematodes and fungi Importation Used for introduced pests most often
Cultural control Maintain plant vigor Especially important with tree borers Borers and bark beetles most often attack dead or dying trees Too vigorous/ too much nutrition- other pests Pest free plants Void of phytophthora Virus free for some trees Esp. if there is an important virus (Prunus spp.)
Cultural Control cont. Pruning Especially important for trees Increase light and air penetration Prune dead and dying, eliminating site for infestation Some diseases controlled by careful pruning i.e. fire blight Sanitation Remove refuge for pests Infected plant parts Example: twig girdler Mulch Make sure it is disease free Species Diversity
Mechanical Control Traps EAB traps for monitoring Gypsy moth burlap bands Sometimes mostly useful as a monitoring tool Removal of pest Scraping/ pruning out egg masses
Chemical Control An important tool Needs to be used in coordination with other methods Because of the size and need for proper coverage and sophisticated equipment, Tree Stewards rarely apply or recommend specific chemical controls.
Dan Nortman York County Extension 757-890-4940 dnortman@vt.edu