While natural predators are very effective, they are not always used successfully. Over the past five years, we have assisted thousands of plant enthusiasts and professionals in using biological control agents. In both homes and nurseries, treatment failures are usually due to a few common mistakes. Here are five things to avoid in order to succeed with natural predators.

1 – Identification error

Natural predator treatments are very targeted. Before preparing an introduction, make sure you have accurately identified the culprit. Aphids, mealybugs and scale insects are unique and usually easy to spot. For flying insects and pest mites, you may need to look a bit more closely. Use a magnifying glass if necessary. If you believe you are dealing with thrips, determine whether they are tropical or native species, as the recommended predators and treatment methods vary.

2 – Wrong Predators

The right tools yield the best results. Make sure you choose the predators recommended for your particular problem. Pay attention to combinations of products when they are recommended to target the different life stages of the pest simultaneously.

Some predators are available in sachets for preventive treatment, and in bulk for curative treatments. Additionally, a specific product may be recommended over another for treating the same pest depending on the situation. For example, ladybugs, which are excellent greenhouse predators, will be relatively ineffective outdoors and may be irritating if used indoors.

3 – Insufficient cleaning

Natural predators feed on their prey. They are voracious, but their appetite is not infinite. If there are too many pests, they will not be able to eliminate the problem on their own. It is essential to prepare your introduction by thoroughly cleaning the plants to reduce the pest population to a minimum.

A strong water jet applied to all surfaces of the plant can dislodge most of the insects. You can then introduce your predators, who will handle the remaining individuals. The more care you take in this step, the better your chances of successfully treating the infestation.

4 – Wrong introduction frequency

Curative treatments using natural predators usually require at least two introductions. Pests have different life cycles, some of which are quite complex. The insects used to combat them also have different predation periods.

Fortunately, the recommended introduction frequency for each predator takes these variables into account. Be sure to follow these guidelines to ensure that the pests you are trying to eliminate are given no chances.

5 – Partial treatment

Pests spread from one plant to another and may go unnoticed for some time. This is why it is crucial to treat all plants at once. While it may seem overwhelming to treat your entire collection, don't assume that some of your plants are pest-free. By not treating all your plants, you risk allowing hidden insects to survive and spread again. The real time and money savings come from a thorough treatment that doesn’t need to be repeated.

Conclusion

You now know the main pitfalls to avoid when using natural predators and are equipped with all the keys to a successful treatment.

If you would like more information on any of the topics mentioned in this article, here are some relevant resources to answer your questions:

• Predator pages (Products tab)
• Pest pages (Resources tab)
  
• SOS Plants
  
• Discussion group