Would you make visiting a hydroponics farm a priority to find out how to control insect pests in your garden or farm? Growing vegetables in plastic trays without soil, and drip feeding them liquid fertiliser, seems a world away from how we envisage using eco-logical approaches to control insect pests.

That’s why I was a little sceptical when a friend insisted on taking me to visit Graham and Fiona Grant’s hydroponics farm in northern NSW, Australia.

Photo of lettuce grown hydroponicallyWardell Hydroponics produces Asian greens, lettuce, and kale

When Graham and Fiona took over the business a few years ago, they struggled to grow greens without the leaves getting decimated by plagues of insects. They fought back with broad action chemical pest controls, killing everything.

Even spraying 3 to 4 times a week wasn’t working. The insect pest populations just bounced back. It was costing them a fortune.

Now Graham and Fiona do things differently.

Controlling Insect Pests Eco-logically

Recognising that they were using the sprays as band-aid solutions, they looked at why their crops were getting insect damage and realised the source of the problem was insufficient predators and parasites to control the pest populations.

Their first response was to replace the synthetic pest controls with ‘bugs to control bugs.’ This is a common approach. Companies worldwide specialise in supplying insect eggs for the predators and parasites of major pests.

Photo of Wardel Hydroponics where they control insect pests - eco-logically

“Buying in bugs wasn’t ideal, though,” Fiona said. “We’re still reliant on purchasing pest controls, and using organic sprays as emergency backups. We wanted to solve the problem for the long term, rather than having to regularly buy-in stuff.”

When I visited their farm in July 2017, they were experimenting with growing plants around their sheds to provide food and habitat for the predators and parasites of their insect pests, thereby enabling their ecosystems to provide natural pest control.

“We want the beneficial insects to complete their life cycle on our farm and rebuild their populations, rather than us buying them in,” Graham said. Plus, the insects are on-site, ready to breed rapidly in response to pest outbreaks.

Graham and Fiona also plant sacrificial crops their pests prefer to eat in approximately every seventh row within their hydroponic system. Because these plants attract pests, monitoring and controlling their numbers is more manageable.

“Now we get more sellable produce – plants are bigger with less damage to the outer leaves.”

Getting Practical

An increasing number of farmers and gardeners are experimenting with using eco-logical approaches to control pests. They’re applying eco-logical principles to develop practices that work well for their growing conditions and the food they grow.

Photo showing strip of flowers in field to attrack beneficial insects

Pest control and pollinator strip in a field

Here are some useful resources to help you on this journey…

  1. What is Regenerative Farming and Gardening
  2. Principles of Regenerative Farming and Gardening
  3. Manage Insects On Your Farm- A Guide to Ecological Strategies
  4. Mimicking Nature: Woodleaf Farm’s Ecological Design

Or get the Eco-logical Farming or Gardening Handbooks to give your whole ecosystem an upgrade!

Front cover Eco-logical Gardening Handbook

Front cover Ecological Farming Handbook

Lead illustration © Jamie Brown, 18th Apr 2014 Rural Weekly.


    5 replies to "How to Control Insect Pests – Eco-logically"

    • Bob

      Good one..

    • Wendy Seabrook

      Thanks Bob – it’s always great to get feedback!

    • Eric

      Fascinating thanks Wendy. We never think that such high tech approaches as hydroponics use very sustainable ecological practices. It seems like a different mind set. So its great to see good examples of how it might work. I fully understand the idea of strategies to boost numbers of predators of the pests, however my question about sacraficial crops is: With most pest species having the capacity to quickly breed up to their alternative food crop’s capacity, wouldnt one just end up with a greater load on the main crop as well?

      • Wendy Seabrook

        Hi Eric
        Good question! I would imagine that they are using the sacrificial crop to focus the pest populations making it easier to control their numbers with organic pest control products. But I will check with Graham and Fiona and get back to you.

        • Wendy Seabrook

          Graham has replied to Eric’s question –

          “Yes that is one aspect [using organic pest control products], but remember the pest has a preference for that sacrificial crop so draws the pest away from the produce, this also provides a concentrated pest density allowing beneficials to be more efficient in this area. This would be the area where beneficials are released and habitats created to sustain their populations. Only when the acceptable threshold of pests is exceeded in such sacrificial crops only then would you consider targeting them with other pest control measure.

          In addition to sacrificial crops there are also dead-end crops, the latter either kills or breaks the life cycle of the pest by rendering the pest infertile . An example is Landcress, it is very effective against Diamondback moth in rendering them sterile.

          The main message is that no individual approach will provide the “silver bullet”. A suite of pest specific approach’s in conjunction with one another should always be adopted for maximum effect.

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