'Pests' are more important for your garden than you think

The literal birds and the bees are the silent heroes keeping our ecosystem churning.

Brussesls sprouts with bugs

Though unsightly, these insects play a key role in plant development. Source: Kitti Gould

--- Stream Gourmet Farmer any time free. Visit the  for recipes, the episode guide and more. ---

 

Of what we eat, there are few foods that don’t need pollination. The only things that don’t need pollination at any time aren’t plants; animals reproduce in a different way.

The way a plant reproduces is by a process in which the male pollen somehow gets onto the stigma – the female part of the flower. Some plants self-pollinate by simply dropping pollen and letting gravity and wind let it drift. If a plant doesn’t require pollination to get to the eating stage (say, celery or a carrot, unlike a fruit such as a pea, an apple, or a melon), then it definitely needs it to get to the stage where we can grow a seed for the next generation.
Bees, and in particular, the European honeybee, are very, very good pollinators.
This pollination, essentially a plant form of fertilisation, can happen by wind (hazelnuts for instance, and wheat and rye), by contact (as often happens with corn), and by something else that touches the male parts of a flower and then the female (stigma) parts of the flower, hence spreading the pollen. That something, many times, is an insect.
Bees, and in particular, the European honeybee, are very, very good pollinators. Some estimates state around one in three mouthfuls of food requires a pollinator of some kind – and the pollinator of choice, in subtropical nations at least, is the European honeybee.

Blueberries, for instance, are estimated to have 95% of their insect visitors as honeybees. Yes, you can pollinate using birds. And yes, indigenous insects are very handy, but in a global sense it’s the classic honeybee that carries the can in terms of animal-induced pollination. You simply wouldn’t get the yield, the success rate, or the variety of fruit and vegetables without them.
Matthew and Sadie walking to the bees
European honeybees do the heavy lifting when it comes to pollination. Source: Tim Thatcher
When we talk about farmed animals, and what lives and dies for us to eat, the bee is the unsung hero. If you use canola oil, sunflower oil, eat almonds (or drink almond milk) or consume broad beans, domesticated bees play a significant part in the creation of these items. Yes, other species can pollinate all kinds of crops, but managed pollinators do a better job most of the time. In fact, in the US, where over 80% of the worlds’ almonds are grown, they estimate that about 80 billion bees contribute to pollination. That’s right, 80 billion!

Bees are vital to produce a viable crop, and some estimates put the number of bees that die in the process at around the half the total. Bees die when transported across the nation, as well as on site. (In Australia, it’s estimated that we use 163,000 hives, so at least 1.6 billion bees.) We use them because they’re very good at the job, and because we have come up with systems to not only manage their population in domesticated hives, but also because the beekeepers themselves can make money from the by-product of much of the pollination work done; honey.
in the US, where over 80% of the worlds’ almonds are grown, they estimate that about 80 billion bees contribute to pollination.
Some other bugs, besides the domesticated honeybee, can also fertilise just about any crop. Insects such as bumble bees and native bees are capable, but native bees are often species-specific; evolved to be the perfect size and shape to pollinate a single plant species, or family of species.

No matter how tailor-made, all pollinators are susceptible to pesticides. Looking at the myriad species of insects that inhabit our garden, by far the majority are either harmless or in fact beneficial in other ways. Killing all insects to remove a pest means taking out a whole layer in the ecosystem. Can we do this forever and not have consequences? Many think not, including the EU, a class of pesticide, neonicotinoids, because of the potential harmful effect on bees and other pollinators.
Fat Pig Farm getting a pollination survey
The pollinator survey on Fat Pig Farm shed light on which insects are doing beneficial work. Source: Tim Thatcher
On our farm, we ran a pollinator survey to see what is doing the work of fertilising our crops. Many times, as you’d expect, it was our bees, or other European honeybees either wild or domesticated. They are the heavy lifters of spreading pollen. But we also have many other pollinators, which provide resilience in the event of bee deaths, or adverse weather and the like. We have hoverflies, some of the 100 or so species estimated to exist in Tassie (though only about 50 have been named). We have native bees, and there are the introduced bumble bees, too, which are great pollinators, though they can be a menace with smaller native plants. Their large size means they can snap off tiny blossoms. There’s also a range of wasps, beetles, and even moths that can pollinate our crops.

One of these, the white cabbage moth is a decent pollinator, but because its young (caterpillars) dine out on our brassicas (cabbages, broccoli, kale etc), we’re not very keen on having them in the garden. This, however, is why insects have to be seen in their entirety. While the white cabbage moth is an anathema to most gardeners, the larvae of the native hoverfly is actually a boon; they love eating aphids, and aphids can sometimes take a hold in the garden. Spray an indiscriminate pesticide and you kill both the good insects, and the bad.
But we also have many other pollinators, which provide resilience in the event of bee deaths, or adverse weather and the like.
We are trying to make the environment welcoming to other insects, besides bees. When we farm, we try to look at layers of ecology. There’s the community beneath the soil of microbes and fungi and the like. There’s the plants growing in the soil, capturing sunlight and creating sugars that all living things need to survive. There’s an insect population that we must manage to ensure we don’t lose our harvest, but also so that we maintain some kind of balance and also to ensure pollination, which is absolutely essential. And then there are some other animals, the birds, mostly, that keep some of the insects in check.

Obliterating all the insects, by using chemicals that indiscriminately kill, isn’t an option in our style of garden. But our experience does seem to suggest that if you ever eat a lettuce, a Brussels sprout, or a cabbage that hasn’t had a scrap of insect damage, someone has probably already killed the insect long before you bought the crop.

For us, insects pollinate and protect our crops. We have even built a small insect hotel; a place where insects can find a home inside hollow wood and crevices. We have wooded areas close to the garden. It’s a fine balance, having insects in the garden, and we don’t always get it right. But, internationally, the results of unfettered chemical use are sobering.
In the greenhouse at Fat Pig Farm
Fat Pig Farm even has insect hotels to attract beneficial species. Source: Tim Thatcher
There are stories about the , after the obliteration of local insect populations. It is possible to pollinate without insects, but it ain’t easy. Luckily for them, in China they have a big and cheap enough labour force to use humans to fill the void in some instances. The use of pesticides has worse implications, however. It is surmised that our use of pesticides has caused a catastrophic not just in Europe and the US but also further afield. Such a rapid shift has scientists worried. What the full effects will be, only time will tell.

Insects aren’t the enemy. Oftentimes they’re helpful, as we see in the pollination of our crops and in the predation of some species of harmful insects. Mostly, insects - including a good mix of pollinators - are essential in a working ecosystem, and a good garden should be a mini-ecosystem all its own.

Matthew Evans explores all things farm to table in season 5 of Gourmet Farmer. Visit the for recipes, the episode guide and more.

Share
SBS Food is a 24/7 foodie channel for all Australians, with a focus on simple, authentic and everyday food inspiration from cultures everywhere. NSW stream only. Read more about SBS Food
Have a story or comment? Contact Us

SBS Food is a 24/7 foodie channel for all Australians, with a focus on simple, authentic and everyday food inspiration from cultures everywhere. NSW stream only.
Watch nowOn Demand
Follow SBS Food
8 min read
Published 3 September 2019 3:48pm
Updated 1 February 2022 4:04pm
By Matthew Evans


Share this with family and friends