The Integrated Pest Management (IPM) Plan for the university’s Custodial and Grounds Services Department has a three-pronged approach which includes:
- Inventory of the university’s woody and herbaceous plants and identification of pest problems.
- Monitoring of areas and organisms that have been pest problems in the past.
- Remediation using management tactics in the context of the particular pest and plant host.
INVENTORY
Our inventory is a database catalog of all the campus landscape trees. Every landscape tree is tagged with a unique identification number. This database identifies specific trees by their species, size, and other inventoried data. There are approximately 15,000 landscape trees.
MONITORING
We use the tree inventory together with our knowledge of the U-M landscape to monitor for insect and disease occurrences and environmental stresses (e.g., leaf and bark scorch, girdling roots, nutrient deficiencies, etc.) before these occurrences become problems.
In cases where the insect or disease occurrence is a problem, we use monitoring as a technique to measure population size and to determine if and when we need to use remediation measures. An example of this technique is using insect pheromone traps to monitor the elm bark beetle population.
We observe and collect weather related data to estimate when certain insects will hatch their eggs and anticipate the outbreak of certain fungal diseases. An example of weather data monitoring occurs in the management of elm leaf beetles using degree-day monitoring. A degree day is a unit based on accumulated heat to measure physiological time.
REMEDIATION
Before applying pest management control measures we determine what action is needed and whether that action is likely to be effective. The majority of our landscape pest problems are minor or do not threaten plant health and therefore no action is taken. When action is needed, we use more than one method in combination to provide more effective control. As a part of our Integrated Pest Management Plan we use cultural, mechanical, physical, biological, and chemical control measures.
We base our pest management program on cultural control. Cultural controls begin with selecting healthy specimen of pest resistant species, properly planting them, and maintaining their vigor with the necessary irrigation and fertilization. Providing plants with the proper care is our foremost consideration and the best line of defense against pests. In addition to proper installation and establishment, we give a lot of time and effort to pruning appropriately to minimize pest problems.
We are attempting to use physical controls, e.g., barriers to prevent plant pests from doing repeated damage. Examples of this kind of control are bands around particular trees to discourage gypsy moth invasion or barriers around the trunks of young trees to prevent damage from dogs and squirrels.
Our biological control attempts have been limited to successful use of Bacillus thuriengensis for the management of eastern tent caterpillar. We are exploring the use of predaceous insects, but have not worked with any species yet.
Annually, we will utilize chemical means for controlling landscape pests such as weeds, insects, and diseases. The use of chemicals on campus is a last resort tactic. We will use the least toxic chemicals available and have had great success using horticultural soaps and oil. All the staff who apply pesticides are certified by the Michigan Department of Agriculture and we heed all of the occupational and environmental precautions and suggestions in addition to ecological common sense.