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A Continuing Wave Of Pest Pressures

August 31, 2017  By Gary Jones

September 2017 – One thing is for sure these days: nothing is for sure. Everyone in the greenhouse industry knows we’re in a global industry. Supplies, labour and produce are increasingly moved around the world in what we’re told is a good thing – “global trade.”

But a recent report from U.K.-based think-tank “Chatham House” suggests differently. “The world’s food security is increasingly reliant on 14 ‘chokepoints’ for trade” and “more needs to be done to protect key transport routes such as the Panama Canal, the Suez Canal and the Turkish Straits.”1

It goes on to further suggest that “Almost 25 per cent of the world’s food is traded on international markets” making food supply and prices vulnerable to unforeseen crises or climate change.


We all know that when food (and flowers) does get through these “chokepoints,” pests and diseases may also get through. We’re then left to fight this fight. “Non-native pests (also known as ‘alien species’ or ‘exotic pests’) are pests that are introduced to a country or region deliberately or by accident, outside of their natural habitat. If the new habitat is suitable, introduced pests can often survive, multiply and spread (becoming invasive).”2

These may or may not be different to quarantine pests: “A regulated (or quarantine pest) is a pest that is regulated at the federal, provincial or municipal level, to prevent its introduction or additional spread. Regulations may prohibit certain plants from being grown in control areas, may restrict the movement or transport of certain plants, products or soil between areas to prevent a pest from spreading, and may require property owners to control certain pests.”2 “The Canadian Food Inspection Agency (CFIA) has the lead role in protecting Canada from the introduction of new plant pests and preventing the spread of certain pests within and between provinces.”2

Whether “non-native” or “quarantine” (some can be both), such pests cause untold financial impact, and we need to build resilient systems to mitigate their introduction, establishment or spread.

The ideal is to “start clean – stay clean” as industry stalwart entomologist Graeme Murphy says. Reporting on research from Vineland Research and Innovation Centre at a Flowers Canada event in B.C. in mid-June, Murphy says that Canada imports over half a billion plants each year, and with them lots of thrips. We need sustainable, responsible ways to biologically or naturally control these and other plant passengers such as whitefly species.

At the same event, U.S. entomologist Suzanne Wright-Evans put out her list of “Challenges for IPM,” which includes:

  • Knowing more about pesticide compatibilities, and
  • Host plant range as it relates to both pests and beneficials.
  • Having staff who are able to identify beneficial species and if they are being effective, including paying attention to product quality (as B.C. entomologist Brian Spencer has been telling us for years!), and
  • Being aware of emerging (in the sense of new) pest species.

Dr. Deborah Henderson, director of KPU’s Institute for Sustainable Horticulture (I.S.H.), put out a similar message based on her work with biocontrol agents, in calling for a re-focus on industry resilience. Effects of climate change (sea level rise, drought, floods, saline soils, etc.) are almost always detrimental to plant growth. We “need to absorb these disturbances”3 and have “multiple tools to manage pest and disease challenges. These could include:

  • Options for different (varied) production systems.
  • Biodiversity of crops.
  • Innovation using local indigenous knowledge.
  • Government, management and social equity (such as the ALR system), and
  • Ensuring we pay attention to livelihood and well-being through healthy local economies.”3

What if this all goes wrong?

There used to be days when growers could get crop insurance reasonably easily – at a premium of course, but do-able. Maybe we need to go there again in the fight against exotic pests.

  1. 1 BBC News June 27th 2017,
  2. 2 Government of B.C.,
  3. 3 Dr. Deborah Henderson, June 14, 2017.

Gary Jones is co-chair of horticulture at Kwantlen Polytechnic University, Langley, B.C. He serves on several industry committees and welcomes comments at

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