Manage mites

Mites are a microscopic menace that can wipe out your crop completely in a matter of weeks, if not days.

If a single female mite produces 50 offspring – a common enough scenario – the pests’ exponential reproduction can result in 13 million new mites just one month later. Warm temperatures bolster their populations, so mite problems peak in the summer across the country.

While mites themselves are difficult to see, their damage is easily visible and can quickly render plants unsaleable. Mites feed on plants directly, leaving a stippled, silver pattern on leaves and flowers, twisted, gnarled leaves and unsightly webbing.

Controlling mites can be a daunting task in any setting, but it becomes more complicated in outdoor nursery settings. Because they’re dispersed over a greater area, even a large mite infestation can be difficult to detect and manage. That can increase costs, especially if expensive tools are applied late in the infestation. Even then, the intervention may come too late to save the plants.

Worse yet, mites attack the bread-and-butter plants in most nurseries. They feed on almost any colored bedding plant, as well as roses, azaleas, camellias, conifers, junipers and more.

Like most pest problems, no “silver bullet” solution exists for mite control. Still, there’s good news: mite infestations can be managed by deploying the right tools before the damage is done.

An Integrated Pest Management (IPM) program provides growers with a proactive approach that is more effective than reacting to an infestation. With an integrated approach, growers can tailor a successful solution for their exact problem and environment, and preserve crop quality and profits.

The integrated approach – What is it?

IPM takes a comprehensive approach to pest control. It relies on stalwart scouting, established thresholds for damage, and a suite of management techniques.

The six guiding principles of IPM widely accepted across the industry are:

1. Establishment of economic thresholds designed to control, but not completely eradicate, pest populations.
2. Regular scouting, monitoring and record-keeping to accurately identify and track pest populations over time.
3. 3. Implementation of best practices to maintain healthy plants without excess water, fertilizer and pesticide.
4. Utilization of mechanical barriers or methods that physically prevent or remove insects from an operation.
5. Use of biological control agents to manage insect populations.
6. Applying conventional, synthetic insecticides responsibly by only treating when necessary and rotating modes of action to limit potential for targeted pests to develop resistance. 
   
    

The integrated approach – Where do I start?

Transitioning from a traditional mite control program to an integrated approach may seem like an intimidating task. But by using the six principles above as a guide and embracing a few key changes, IPM can help growers sustainably control mite populations.

Get started with these steps:

1. Know your operation. Growers face competition for their time and attention, especially during peak season. They need to be deeply familiar with the variables that affect their growing operations and crop quality, taking time to educate themselves and their teams.

2. Learn proper identification. Growers must be able to identify – or work with someone to identify – the pest species in their area, particularly if they are using a beneficials program. In operations using beneficial predatory mites to help control pest populations, employees must be trained to see the difference between mites that help protect plants and those that harm them. Differences can be difficult to see on such small arthropods, so care must be taken to be accurate in identification.

3. Determine your thresholds and approaches. Growers need to establish an economic threshold for each crop, deciding the level of mite pest pressure that necessitates action. The economic threshold is usually well below the damage threshold, which is the pest pressure level that would result in reduced crop quality and economic loss. Determine the actions that will be taken once the economic threshold is reached; this prevents a lengthy decision-making process when it’s time to act.

4. Scout and monitor. When it comes to IPM for mites, there are several key scouting practices to follow:

• Scout once or twice a week during the production season–no exceptions. Growers must allocate resources and expertise to this task. Take time to develop and teach valued employees how to scout and identify the economic pests of your business during the course of their other daily responsibilities.
• Scout early. Quarantine incoming plant material to prevent introducing pests to other areas of the facility. Inspect new plants and cuttings as they arrive to help identify the source of pests and begin to control them before populations rise. Continue to monitor pest (and beneficial) populations throughout the growing season.
   

If an infestation occurs, flag problem areas, and keep a close watch for pest pressure to trend towards your action threshold.

Keep detailed records. Record the number of mites per a given amount of area (for example, per leaf or per plant). Create a map or outline of areas with higher infestation levels. Detailed records will help determine when mites become a problem and when to implement control measures.

5. Treat preventively. Release beneficial insects early to prevent high infestations from occurring. Make regular applications of beneficial mites and other chosen pest control methods, monitoring their numbers and activity just as you would with a pest. Keep records for this activity as well; they can be used to determine which beneficials provide the best control and at which population numbers.

6. Use targeted chemistry. When necessary, deploy effective chemistry that is targeted and reliable. The toolbox of controls works best when the right material is applied at the right time to reduce management costs, and avoid potential crop loss or quality problems. More selective chemistries are becoming available that work hand-in-hand with IPM programs. Products that are safe on beneficial insects and predatory mites are in greatest demand.
 

The integrated approach – A long-term solution

By adopting IPM practices, growers can develop programs tailor-made for their growing environment. Established, mature IPM programs allow growers to use tools more efficiently and effectively. The result: successful mite management and a high-quality crop.

Joe Lara is a Senior Product Manager for BASF.