What is integrated pest management?

An order of operations rather than a smaller chemical programme. European law defines it as eight principles: prevent, monitor, decide against a threshold, then intervene with non-chemical methods preferred where effective, using specific products at minimum necessary levels, managing resistance and checking whether it worked.

Does biological control eliminate the pest?

No, and it is not meant to. Predators and parasitoids hold a population below the intervention threshold, and a residual pest population is what sustains the predator. Success looks like a controlled low level rather than absence, which is why spraying on first sighting undermines the programme.

Which beneficial insects are standard in a greenhouse?

Encarsia against whitefly, Phytoseiulus against spider mite and Orius against thrips are the long-established ones under glass. Which are released, and at what point, follows the crop and what monitoring shows rather than a fixed calendar.

Integrated Pest Management (IPM) in Greenhouses

Q: Why run IPM if chemical control is available?

Because chemical control is a depleting resource. Every application selects for the individuals that survive it, and the authorised product list for greenhouse crops has been shrinking for years. IPM exists to keep that narrowing toolbox effective; the environmental benefit is real but it is a consequence rather than the founding reason.

Not a smaller chemical programme — a different order of operations

The first reason to run integrated pest management is not environmental, it is that the chemistry runs out. Every application selects for the individuals that survive it, and the authorised product list for greenhouse crops has been shrinking for years, so a grower who leans on chemical control is spending a resource that does not replenish. IPM exists to keep a narrowing toolbox effective for as long as possible; the lower environmental load is a real and welcome consequence rather than the founding purpose.

European law defines it as eight general principles, and the order encodes the method. Prevention comes first, through cultivar choice, hygiene, substrate and climate, and through protecting the organisms that do the work for free. Monitoring comes second, because nothing after it can be decided without counts. Third is a decision against a scientifically defensible threshold rather than against the sight of a pest. Only then does intervention follow, and non-chemical methods take precedence wherever they are effective.

In a greenhouse the non-chemical layer is largely biological. Predators and parasitoids — Encarsia against whitefly, Phytoseiulus against spider mite, Orius against thrips — are released to hold populations below the threshold rather than to eliminate them, which is a real shift in what success looks like: a residual pest population is what feeds the predator that controls it. That inverts the instinct to spray on first sighting, and it is the single hardest habit to change.

It also constrains what may be applied afterwards. A product that clears the pest and the predator leaves the crop less defended than before, so any intervention has to be selective enough to spare the beneficials and safe for the pollinators living in the same volume. DutchGreenhouses® specifies the exclusion, climate and monitoring systems that make a biological programme viable, so the greenhouse supports the strategy rather than undermining it. Get in touch to discuss an IPM strategy for your crop.

From the knowledge base