Combining Beneficials with Sprays: A Practical Guide

Understanding Compatibility

Beneficial insects and mites are living organisms, and their survival depends on avoiding harmful residues. Some pesticides are completely incompatible, while others have minimal impact. The Koppert One Compatibility Tool allows growers to check compatibility by entering a chemical and a beneficial species. Hovering over the icons or using the legend reveals whether a product is harmless, slightly harmful, or very harmful. This step ensures that chemical applications do not compromise biological control.

To support quick decision-making, compatibility charts summarize the effects of common active ingredients on beneficial species. These charts show that microbial products such as Bacillus thuringiensis israelensis (BT) are generally safe, while pyrethrins, acephate, and synthetic pyrethroids are highly harmful. Oils, soaps, and essential oil blends fall in the middle range, causing moderate mortality and requiring caution.

Interpreting the Charts - See our Compatbility Charts here

The first chart rates household and garden products by their impact on beneficial insects. Products like Fungus Gnat Death Drops, which contain BT israelensis, have a low to no mortality rate and can be used alongside soil predators and nematodes. Neem oil and essential oil blends cause low to moderate mortality, meaning they should be applied carefully and preferably as spot treatments. Spinosad, pyrethrins, and systemic insecticides such as acephate are listed as moderate to high or high mortality, making them unsuitable during active biological programs.

The second chart addresses different species and their compatibility with common chemicals. For example, Entonem nematodes are harmless or only slightly harmed by potassium salts of fatty acids and copper compounds but moderately harmed by acephate. Swirski-Mite and Ulti-Mite sachets are very vulnerable to acephate and pyrethrins. Predatory mites such as Spidex Vital and Spical are also highly sensitive to these active ingredients. Parasitoids like Aphipar and Ervipar show severe incompatibility with acephate and pyrethrins but tolerate softer chemistries such as Bacillus subtilis.

Practical Application: Real-World Combinations

Fungus Gnats in Propagation

Biological control begins with Entomite-M (Stratiolaelaps scimitus) in the upper soil layer and Entonem (Steinernema feltiae) nematodes for curative action. When pest pressure spikes, BT israelensis can be applied as a drench without harming these beneficials. This combination works because BT is rated as low to no mortality for beneficial species, allowing nematodes and predatory mites to remain active.

Thrips and Whiteflies on Ornamentals

Swirski-Mite sachets and Orius insidiosus provide strong biological control. If disease prevention requires a fungicide, Bacillus subtilis is a safe choice because it is harmless or only slightly harmful to these beneficials. Avoid pyrethrins or spinosad during active releases, as they are very harmful and will eliminate predator populations.

Root Aphids in Container Production

Root aphids require a different approach. Biological suppression above ground can be achieved with Aphidius spp., but root-zone control relies on Isarid (Isaria fumosorosea) combined with a neem-based concentrate as a drench. This treatment reduces root aphid pressure without harming soil predators like Entomite-M. Ant control and sanitation are essential to prevent reinfestation.

Best Practices for Combining Sprays and Beneficials

1. Check compatibility before spraying. Use the Koppert One tool or reference charts to confirm safety.
2. Sequence applications correctly. Apply harmful chemicals before introducing beneficials, not after.
3. Spot treat whenever possible. Reduce exposure and preserve beneficial populations.
4. Choose softer chemistries. Microbial products and selective fungicides are generally safer.
5. Communicate with your team. Make compatibility checks part of your IPM workflow.

The Bottom Line

Combining beneficials with sprays is not complicated. By using compatibility tools and understanding which products are safe, growers can maintain biological programs while managing outbreaks effectively. IPM is about balance, and with the right information, beneficials and sprays can work together to protect crop health.