Pesticides influence the success of biocontrol

Figure 1. Population growth over a single generation comparing natural enemies exposed to pesticides to those not treated.

More about pesticide effects on natural enemies can be found in our 2012 annual progress report under Objective 1.

These results suggest that certain pesticides are more selective than others and that it may be difficult to conserve all natural enemies under all circumstances, making it important to know which natural enemies and pests are present in your orchard. This information can assist pest management decision makers in selecting pesticides that will help to enhance and conserve natural enemies in their orchard operations.

The pesticide effects shown in the table below are grouped by color with respect to their severity:

• green indicates that a pesticide is selective and compatible with the natural enemy (0-25% reduction, i.e. the exposed population is up to 25% smaller than the unexposed population),
• yellow indicates an intermediate effect that is readily observed under laboratory conditions and may or may not translate to an effect under field conditions (25-75% reduction, i.e. the exposed population is 25-75% smaller than the unexposed population), and
• red indicates that a pesticide is non-selective and likely to show disruption of natural enemy populations under field conditions (75-100% reduction, i.e. the exposed population is more than 75% smaller than the unexposed population or shows no growth at all).

For the natural enemy description click/hoover over the image. Detailed information about the Acute and Sublethal effects can be seen by clicking/hoovering on the word links below each colored value. For an explanation of that data, click/hoover on the following links:  Acute   Sublethal.

Extras