Integrated Pest Management for Soybean Insects

Integrated pest management (IPM) protects against yield loss to insects, weeds and disease. IPM utilizes multiple strategies including chemical and cultural methods of pest control to improve profitability and stewardship. IPM provides many benefits for growers, society and the environment, including greater flexibility, better use of resources, opportunities to increase yields and profits, and reduced potential for resistance development.

For soybean growers, IPM to manage insects includes using seed treatments, scouting and identifying insect pests, making timely insecticide applications when needed, and using cultural practices to diminish the threat from insects. Growers should take the time to explore options that best fit circumstances in their fields.

Seed Treatments

The use of a seed treatment insecticide is one way to provide effective and economical insect control in soybean production. Seed treatment insecticides provide immediate protection from feeding damage from early-season above- and below-ground insect pests that otherwise might require a foliar spray or replant. For below-ground insects, such as white grubs and wireworms, there are no effective curative foliar treatments.

Scouting

After soybeans emerge, consistent scouting that includes sampling and insect identification is the best way to know what pests are in the field and their potential to threaten yields and profits. Scouting methods vary by insect pest, soybean variety, timing of planting and geographic location, but general best practices include:

• Start at a different point each week.
• Pick a random pattern, chosen in advance, and walk without consciously choosing good or bad areas.
• Sample after regular intervals — every 20 steps or so.
• Walk to within 30 feet of each field edge, as many problems start from the sides of the field.
• Take samples of insects and scan the entire field while walking from one site to the next.
• Consider using a sweep net, a cost-effective way to collect many insects in a short period of time.
• Observe the plants around the sample site while looking for patterns or variations.
• If insects and damage are not easily identified, consult county extension personnel or a pest identification guide.
• Sign up for pest alert emails from your state’s extension program. This can be a helpful way to know which insect pests might be moving into the area.

Insecticide Applications

Thresholds for pest populations that require insecticide applications vary. The decision should be based on timely regional information from sources such as a university extension service. To determine if an insecticide application is warranted, consider the growth stage of the soybeans and the amount of feeding damage. For example, soybean plants can withstand as much as 35 percent foliage loss up to the blooming period. During blooming and when pods begin to form and fill out, any foliage loss of more than 20 percent will decrease yield, according to Mississippi State University research.

Cultural Practices

Cultural practices can affect insect pest populations and the threat for damage to soybeans. The use of no-till or reduced tillage management systems and cover crops can intensify insect populations as they build up in crop residues prior to planting soybeans. Managing crop residue can help control insect pests that favor fields with relatively higher levels.

Weed control is also critical as an insect management tool. An herbicide burndown application three to four weeks prior to planting can reduce infestation risks. Additionally, timely herbicide applications during the growing season can reduce insect breeding areas in host weeds such as pigweeds, waterhemp and marestail.

Growers should also consider crop rotations to aid in the management of insect pests. Some crops do not serve as a host and can limit insect populations for the following year. The management of alternate plant hosts of insect pests should also be considered in soybeans. For example, try to plant soybeans away from buckthorn, which is a host plant needed to complete the soybean aphid lifecycle, a serious soybean pest.

Additional tips include:

• Scout field margins adjacent to alternate crops to monitor migrating insect populations.
• Sample periodically for the presence of soil insect pests. This can be helpful in determining their densities.  When the soil is disturbed during land preparations, growers can use this opportunity to scout for soil-insects that may be exposed, such as white grubs and wireworms.
• Consider shifting your planting date to avoid predictable insect flushes.

Disease Vector Management

Certain insects carry or transmit diseases in soybeans. Management of potential disease transmitting insects such as soybean aphids and bean leaf beetles can reduce the likelihood of additional yield loss due to secondary disease transmissions or infections.

Bayer Solutions to Help Control Insect Pests in Soybeans

The best approach to managing insect pests in soybeans is to integrate multiple control strategies. Bayer offers season-long pest control options from seed treatments to foliar insecticide products. Always read and follow label instructions and confirm the product is effective on the pest you need to control. Not all products are registered for use in every state.

Baythroid^® XL insecticide performs on a broad spectrum of insect pests with fast knockdown and long residual control. Leverage^® 360 insecticide with Stress Shield™ protection enhances the crop’s ability to handle a variety of stresses, such as soybean aphids, to maximize yield potential.

Contact your local Bayer representative for information on solutions from Bayer to maximize yields and protect soybean crops.