Keeping Insecticides in the Toolbox

5 questions for an entomologist about insect resistance

New insecticide technology development is slowing down. Because of this, it’s essential to ensure current tools remain available. As insect resistance becomes more prominent, take precautions to prevent insect resistance to keep current tools and resources available.

Jeremy Greene, Clemson University entomologist, shares why insect resistance is a critical variable for farmers to manage.

 

Five Questions for Jeremy Greene, Ph.D., Clemson University Entomologist.

Q: Why is insect resistance a threat?

A: Chemical control of harmful, economically important insects is a valuable strategy for managing insect problems, yet development of new insecticides has slowed to a crawl compared with production of insecticides decades ago. Because there are far fewer options available today, we can’t afford to lose what we have to resistance. Losing some or all of these insecticide technologies would have significant impacts on yield, as we would no longer have the capability to control these pests. In turn, this would lead to profit loss.

Q: Why is managing insect resistance important?

A: We must preserve the insecticide chemistries we have. Managing insect resistance through responsible use of those materials increases the longevity of our current insecticide options.

Q: What are the best management practices to ensure that insecticide technologies remain viable?

A:

  1. Practice integrated pest management    
    • Integrated pest management (IPM) strategies include biological control, cultural control, physical/mechanical control, reproductive control and more. These methods of control should come before using chemicals to control insect pests, as some of these strategies eliminate the need for insecticides. Chemical control should be the last resort.
  2. Follow economic thresholds
    • When insecticide use is required to prevent economic injury, producers should follow established treatment thresholds to determine when to use insecticides. This can be accomplished by scouting the crop for levels of infestation and damage and selecting the most appropriate insecticide. Insecticides should not be applied if infestation levels are below the threshold.
  3. Use recommended rates and proper equipment for delivery
    • Because some insecticides work better on some insects, the proper formulations and methods of application must be used to maximize product efficacy. Determine proper formulations through reading local recommendations and following the pesticide label. Once a proper insecticide is selected, it’s important to apply the recommended rate.
  4. Rotate modes of action
    • Avoid repeated applications of the same class of insecticide when follow-up applications are required. Rotating chemistries preserves each mode of action, as the same generation will not be exposed to the same insecticide. Insect pests that survived the first application can be removed from the population with a follow-up application of an effective insecticide with a different mode of action. Refer to the product label to find the mode of action in the chemistry you’re using.

Q: Which insects are most susceptible to developing resistance to insecticides?

A: Insects and other arthropods, such as spider mites, with short lifecycles can produce multiple generations per season. These are some of the most common species prone to develop resistance to insecticides (or miticides). When more generations are exposed to insecticides, it provides increased opportunities to develop resistance. Also, insects that feed on one or a limited number of crops can be exposed to the same insecticides over and over again, which again demonstrates the importance of rotating insecticide modes of action.

Q: What does the future of insect resistance management looks like?

A: The industry is at a critical juncture in managing resistance to insecticides. New insecticides are being developed and registered for use at a much slower pace than in the past. Because of this, it is becoming more and more important to actively delay the development of resistance to insecticides currently in our “toolbox” of IPM strategies. This is why implementing management strategies —like rotating modes of action, using the recommended full labeled rate and using insecticides with high efficacy ratings —is crucial.

For more information on insect resistance management in soybeans, visit www.IWillTakeAction.com.