The Challenge of Pyrethroid and Neonicotinoid Insecticide Outdoor Use Restrictions

In recent years, the labels for pyrethroid and neonicotinoid products have undergone changes mandated by the EPA. In short, these changes are designed to prevent/minimize the amounts of these insecticides moving off-site into sewers or bodies of water and also to protect pollinating insects.

In the scheme of controlling pests around structures, these label changes should not prove difficult to understand or to implement and still provide the desired levels of control of target pests. Pest professionals simply need to recognize situations where certain types of applications with these insecticides may not be permitted and to adjust their approach in dealing with specific pest infestations.

Limiting Potential Runoff.  When inspecting a home or business, pest professionals should take note of any hard, impervious surfaces such as concrete or asphalt next to the building. In particular, those type of surfaces that may lead to gutters, ditches, or waterways where runoff following rainfall or irrigation could potentially carry insecticides off site, in particular driveways or sidewalks. It is around these areas that certain applications will be restricted.

Restricted treatments on or over impervious horizontal treatments will mostly affect perimeter treatments where, typically, application is made so many feet up and out from a foundation (according to a product’s label). Onto or over a concrete driveway or sidewalk that leads to a driveway or to a street or ditch area, you will be restricted to crack and crevice or spot treatments only. 
• General surface applications to large areas are not permitted directly to horizontal imperious surfaces that may lead to off site areas.
• These restrictions do not necessarily apply to any patio, porch, etc. that leads only to lawns, landscaped areas, or bare soil. Also, wood decks over soil areas are not affected by these label restrictions.
• A pinstream treatment may be applied into expansion joints and other cracks in the horizontal surface or into foundation walls.
• Spot treatments measuring up to 2 square feet (288 square inches) in size may be applied to sites where pests are found or may crawl or trail (i.e., ants).
• Spots treated may be a rectangle up to 1 foot by 2 feet or be a longer, narrow application such as 3 inches wide by 96 inches long (0.25 feet × 8 feet). 
• Say you have ants trailing along a crack in a patio—you can apply a narrow band (spot) treatment (i.e., 2 inches wide) all along this trail as long as you don’t exceed a total of 288 square inches. The same applies if the ant trail was on a brick wall over a driveway—apply a narrow band along the area with the trail.
• Exempted Sites—Areas that are directly protected from rainfall or irrigation may be exempted from these application restrictions.  These include underneath soffits/eaves and covered porches or patios. In such sites, you may be able to apply general surface applications (larger than a spot treatment). Check the product label for specific directions.

Protecting Pollinators. Bees, butterflies, wasps, flies, and other insects that visit flowers can be pollinators and need to be conserved and protected as much as possible. In particular, any product containing a neonicotinoid insecticide will have a Protecting Pollinators section included on the label. 

• In short, pest professionals need to be aware of and careful when flowering plants are present in areas where treatments may be made outdoors. This includes plants that may be budding or just about to bloom.
• Direct applications to plants that are in bloom or about to bloom should be avoided.
• Take care to avoid applications when bees or other pollinators are active in an area.
• Understand that drift during application can pose a hazard to pollinators. For example, avoid applications to surfaces above where plants are in bloom or bees/pollinators may be active.
• Many of these insecticide products will permit applications to landscape plants, trees, or ornamental shrubs in order to control landscape pests, mosquitoes, or even ants. Such applications are not permitted when such plants are in bloom or about to bloom.
• In Oregon especially, products containing neonicotinoids cannot be applied to basswood, linden or Tilia sp. trees. Check the label to see if this restriction also applies in your state.
• Be aware if any private or commercial bee hive may be on the property or an adjacent property. Take steps to avoid spray drift to such hives.
• In general, the application restrictions described above may be good practice to follow with any exterior treatment of any insecticide in order to minimize potential impact to pollinators.