Biological control is one of the most powerful tools in modern Integrated Pest Management (IPM). Predatory insects, mites, parasitoids, nematodes, and microbial solutions can suppress pests greatly, protect crop quality, and reduce reliance on chemical pesticides.
Yet despite their proven effectiveness, beneficial organisms sometimes fail to perform as expected. Not because the biology is flawed, but because of improper storage, handling, or release.
Beneficials are living organisms. They breathe, move, and respond to temperature, humidity, and light. They have very specific needs. Small mistakes made between delivery and release can dramatically reduce their survival and effectiveness.
This article walks through how to properly store and release beneficials, highlights the most common mistakes, and explains why these details matter, so you can get the full value from every introduction.
Why Proper Storage and Release Matter
Small handling mistakes, such as storing at the wrong temperature, holding products too long, or releasing under unsuitable environmental conditions, can reduce survival, limit movement, or prevent beneficials from establishing where pests are present.
Proper storage and release practices protect the biological activity of beneficials. When introduced under the right conditions and distributed correctly, beneficials can disperse, locate pests efficiently, reproduce, and provide more uniform and reliable pest suppression throughout the crop.
The goal of proper storage and release is simple:
-
Keep beneficials alive.
-
Maintain their energy and reproductive potential.
-
Ensure they reach the pest quickly.
-
Maximize establishment in the crop.
Poor handling can lead to:
-
High mortality before release.
-
Delayed or decreased efficacy in pest control.
-
Uneven distribution.
In most cases, performance issues can be traced back to preventable handling errors.
Understanding the Different Types of Beneficials
Before talking about storage and release, it’s important to understand that beneficial organisms behave differently from one another. Each group has its own biology, life stage, and survival limits. Treating all beneficials the same is one of the most common causes of failure in biological control programs.
At a basic level, beneficials fall into three major storage groups, each with distinct handling needs.
1. Predatory Mites/Predatory Insects:
Examples: Amblydromalus limonicus, Amblyseius swirskii, Chrysoperla carnea, etc.
Predatory insects and mites are active hunters. They move continuously, search for prey, and rely on stored energy until they find food in the crop. Because they are alive and mobile during shipping and storage, they are particularly sensitive to environmental stress.
These beneficials are affected by:
-
Temperature: Warmer temperatures increase activity and energy use, causing them to starve more quickly. Temperatures that are too cold can slow them down excessively or kill them.
-
Carbon dioxide buildup: Poor ventilation during storage can lead to CO₂ accumulation, which reduces survival.
-
Humidity: Low humidity can dry them out, especially small-bodied mites. High humidity can cause issues with the carrier material.
-
Rough handling: Shaking, squeezing, or dropping containers can physically damage legs, wings, or mouthparts, reducing their ability to hunt once released.
Predatory insects and mites must be stored at the correct temperature, handled gently, and released as soon as possible. The longer they are held, or the more stress they experience, the less effective they will be once in the crop.
2. Parasitic Wasps (Parasitoids) / Gall Midges:
Examples: Encarsia spp., Eretmocerus spp., Aphidius spp., etc.
Parasitic wasps and gall midges are very different from predators. Most are shipped as pupae, some of which are inside host insects (often referred to as “mummies”). At this stage, pupae are not feeding or moving much, but they are undergoing critical development. Because of this, they are extremely sensitive to temperature, which controls how fast or slow they develop.
These products must be stored and released on a tight schedule. Timing matters, not just for survival, but for ensuring adults emerge in the crop. This way, they can quickly lay eggs, starting the pest control process. Once placed in the growing space, it is important to leave the product out for up to two weeks to ensure all pupae have hatched from their respective packaging.
3. Entomopathogenic Nematodes:
Examples: Steinernema feltiae, Steinernema carpocapsae, etc.
Entomopathogenic nematodes are microscopic worms that actively seek out insect pests in growing media or on sprayed leaves. Unlike insects and mites, nematodes are shipped in a dormant, but living state, suspended in a carrier or gel.
Although they do not move much during storage, nematodes are still highly sensitive to temperature. Temperature impacts nematodes by:
- Killing them outright if they freeze or overheat
-
Shortening shelf life when stored above or below the recommended temperatures
Nematodes must be stored within a narrow temperature range and used before their expiration date. Improper storage may not be obvious; nematodes can look fine but perform poorly after application.
Proper Storage: What to Do (and What to Avoid)
As soon as beneficials arrive, open the package, check contents and instructions, and place products directly in the growing space. If you must store the products, do so for only 1-2 days after receipt, and place the products in the recommended storage environment. This information is found on our website product pages, as well as in the “How to Use” emails we send you. Each additional day in storage increases mortality and reduces vigor.
The most common mistake is leaving boxes on a loading dock, desk, or greenhouse bench. Temperature is the single most important factor in storage. Delays at the wrong temperature can reduce the product's viability. If it is stored too cold, beneficials may die or suffer irreversible damage. If it is stored too warm, increased metabolism leads to starvation and exhaustion.
Typical storage ranges:
-
Predatory mites, parasitoids, gall midges, and predatory insects: In a cool, dark place, around 14°C until use. Do not store the products in the fridge.
-
-
Except for Spidex, Spidex products need to be stored between 8-10°C. Do not store the products in the fridge.
-
-
Nematodes: In the fridge between 2-6°C.
Preparing for Release: Setting Beneficials Up for Success
1. Match Release Timing to Pest Pressure & Spray Program:
Other common mistakes include releasing beneficials after pest populations are already out of control, releasing the incorrect product for pest prevention, or releasing beneficials after or during a chemical spray.
Before releasing beneficials, understand:
-
Biological control works best when pest populations are low to moderate. Preventative or early-intervention releases consistently outperform reactive ones.
-
Even products labelled as “soft” or “compatible” can harm beneficials if applied too recently, used at high rates, or mixed improperly. Always look into recent pesticide applications and the chemical's residual toxicity.
-
Observe recommended re-entry intervals for beneficials; not just workers. You can also use our Koppert One app for compatibility references: Koppert One.
2. Release During the Right Time of Day:
The best release conditions for beneficials are early morning or late afternoon, where there is lower light intensity and moderate temperatures. Try to avoid the midday heat, direct sunlight, and dry, windy conditions. Releasing during extreme conditions increases stress and dispersal losses.
Proper Release Techniques: Getting Beneficials Where They’re Needed
1. Distribution:
When releasing beneficials, do not place them all in a single location. This can result in uneven pest suppression, leaving untreated hotspots and slowing overall control throughout the crop. To avoid this, it’s important to distribute beneficials systematically, walking the crop and applying them where they are needed most. Before releasing, consider your strategy: are you applying preventatively, curatively, or targeting specific hotspots? Also, think about the biology of the beneficial. Does it crawl through leaves, move through soil, or fly? Understanding how the organism disperses will help ensure even coverage and maximize its effectiveness against pests.
2. Keeping Beneficials in the Crop:
Certain beneficials are designed to remain in the crop for extended periods to establish and provide ongoing pest control. For example, sachets should typically be left in place for 2–6 weeks, depending on the type, allowing beneficials to emerge gradually and disperse naturally.
- Plus: 3-4 weeks
-
Ulti-Mite: 4-5 weeks
-
LD: 4-6 weeks
-
Spidex Vital Plus sachets: 2 weeks
-
Spidex Boost: 1 week
Bottles of parasitoids and gall midges, the whitefly parasitoid cards, as well as products placed in diboxes (predatory insects), should generally be left in the crop for around 2 weeks to ensure that beneficials emerge, find pests, and complete their life cycle. Removing these release units too early can reduce hatch-out rate, in turn reducing establishment and limiting overall pest suppression. Leaving them in for the recommended duration ensures a steady and effective biological control presence.
The Most Common Mistakes—Summarized
-
Incorrect storage length after delivery
-
Storing at incorrect temperatures
-
Releasing during extreme heat or sunlight
-
Ignoring pesticide residues
-
Poor distribution in the crop
-
Removing the carrier material from the crop too soon
Avoiding these mistakes can dramatically improve outcomes.
Respect the Biology
Beneficial organisms are not inputs like fertilizers or chemicals; they are partners in nature. When handled with care and released correctly, they can outperform expectations and become the foundation of a resilient IPM program.
Proper storage and release are not minor details. They are the bridge between failure and performance. By respecting their biology, following best practices, and avoiding common pitfalls, growers can unlock the full power of biological control and let nature do the work it does best.
