Listen via audio below, or scroll down to continue reading the blog
By Kim Deans
What if we took a different perspective to how we see insect pests? Instead of focusing on how to kill insect pests, what if we chose to see them as indicators about the health of the agricultural ecosystem instead? Insects are not creating damage to agricultural production due to an insecticide deficiency, so why do we react as though they are?
My university agricultural science education was focused on identifying insects as pests or beneficials, using economic thresholds to guide decisions about when to apply insecticides and then understanding how integrated pest management can help maintain the effectiveness of insecticides. This outfitted me well for working as a bug checker in the cotton industry early in my career. It was when I began experiencing these methods from within a family farming business that a different point of view gradually began emerging.
As a farmer, when we decided to apply that first insecticide or any pesticide to a crop, we invested time, energy and money into the crop that then had us locked us into an ongoing cycle of reinvestment in pesticides. Without continuing to apply pesticides, the investment we had already made in protecting the crop would be lost. Whenever we invest in any form of chemical intervention, costs of production rise, and put more pressure on controlling pests, diseases and weeds to chase higher yields to pay for these costs and have some income left over to keep the business going.
One season, our house on the farm was surrounded by dryland cotton fields and I experienced the chemical cocktail that was being applied to the cotton at very close range. This was a season of frequently evacuating myself and my two young sons when the spray planes came in, returning home and breathing in the toxic smell of chemicals, and knowing that our backyard where the boys played had been covered in an invisible film of spray drift. When my first marriage ended and I left this farm it was a huge relief for me to become free of breathing in that smell of the agricultural chemicals in the air. I knew my future career in agriculture was going to look very different to what I had experienced so far.
These experiences made me curious to learn about different approaches to agriculture and send me in the direction of biodynamics, permaculture, soil health and agroecology. My mindset has gradually been shifting along the way. I started where many of us do, by looking for nicer ways to kill the pests other than using chemicals, until I realised that this was not really changing anything. I was doing the same things and expecting a different result. I was still assuming that the insect in question was bad, and I was still asking the same question, how do I kill it?
My approach is evolving, it’s now more about asking different questions, and getting curious and observing before reacting to intervene. Asking things like: what role does this insect have in the ecosystem? What relationships have broken down and disrupted the balance in the ecosystem? How do we restore balance?
This spring we have had an abundance of hoverflies in our garden. In addition to the pollination benefits adult hoverflies provide, hoverfly larvae eat aphids, scale insects, thrips, mealybugs, mites and small caterpillars. This means that for us to have the benefits of the hoverflies we also need the insects we have been taught to see as pests to feed their larvae! The hoverflies reminded me that all insects are beneficial. Labelling insects as good or bad misses the essential roles they all play. Even when insects are eating our crops, they are still fulfilling vital roles in the web of relationships that build the foundation for ecosystem health, such as:
Pollination: bees, butterflies, moths, flies, beetles, wasps
Decomposition and recycling: dung beetles, carrion beetles, termites, slugs and snails, maggots, springtails.
Predators for pest control, predatory insects like ladybeetles, praying mantis, dragonflies, assassin bugs, lacewings, hoverfly larvae, keep pest populations in check.
Prey, providing food for other animals: birds, amphibians, reptiles, freshwater fish, small mammals: cicadas, caterpillars, moths, aphids, termites, native cockroaches,
Soil engineers: ants and burrowing beetles that aerate the soil, creating pathways for water and air.
There are also a few interesting theories that keep me curious in relation to insects. William Albrecht was a professor of soil science and in the 1940’s he suggested that insects are natures garbage collectors after observing insects attacking unhealthy plants before they could reproduce.[1] Phil Callahan researched plant insect communication systems in the 1960’s and suggested that plants and insects communicate with each other in the infrared spectrum.[2] Phil claimed that unhealthy plants emit a different spectrum to healthy plants, with the high ammonia concentration in unhealthy plants enhancing the infrared signal so insects see them, while they don’t see the healthy plant.
When we consider this concept of healthy and unhealthy plants in the field, we realise that plant health is connected to a combination of interrelated factors in the environment. Factors like soil health, plant nutrition, soil moisture, and fertiliser use are all at play. John Kempf’s plant health pyramid[3] is a great foundation for understanding the complexity of nutrition and soil microbial health factors that create healthy plants able to resist insect attack. Studies have also linked nitrogen fertilisers to increased prevalence of insect attack.[4]
In nature, plants have co-evolved within ecosystems that contain a diversity of insects carrying out vital roles. We can help to restore this balance by restoring and creating habitat to provide food, water and shelter for all insects and the animals that will help keep them in balance. Understanding the value of having foliage, groundcover, rocks, and dead vegetation in the environment and resisting the idea of needing neatness is vital for preserving biodiversity.
Changing how we relate with insects in agriculture is what can make the most positive change for the better. This starts by embracing curiosity and observation. Before we reach for a control measure it is vital that we learn to identify the insect and then go beyond labelling it as a pest or beneficial; to learn about its lifecycle, its role in the ecosystem, what it requires, and what helps to keep it in balance. If we have insects creating damage this understanding will help us to assess the possibility of whether their population can be brought in check naturally. This also requires us to learn to become patient enough to allow some time for the predatory insects or other animals that rely on the insect pests for food to breed up and restore balance.
For me taking this approach helps deepen my connection with the ecosystem around me. I love the ongoing learning this approach brings me. I have made some fascinating discoveries as a result, including finding snail parasitic blowflies in our garden who lay their larvae on snails for food, then the adults feed on pollen and nectar. Changing our questions, staying curious, observing and shifting from fighting against nature to looking for ways we can work with nature is so much more enjoyable.
I realise this approach is a big step with risks to manage when the biodiversity and life in the agricultural ecosystem are running on empty. In these types of situations starting with some small experiments where you can create some biodiverse patches of life within the farm to observe and learn as you go is a great first step.
This blog is written by Kim Deans with no thinking, images or writing done using AI.
[1] Advancing Eco Agriculture, Insects are nature’s garbage collectors, Youtube.
[2] Advancing Eco Agriculture, Insects are nature’s garbage collectors, Youtube.
[3] John Kempf, The plant health pyramid, Advancing Eco Agriculture.
[4] Miguel A Altieri, Clara I Nicholls and Marlene A Fritz, Manage insects on your farm. Impacts of fertilisers on insect pests, Sustainable Agriculture Research and Education, 2005.