Nanogirl Michelle Dickinson: Pursuit of the perfect garden is blowing away our insect population

A tidy garden reduces the amount of debris and overturned leaves that are safe shelters for many insects.

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New Zealand is filled with thousands of different insects, many of which are unique to us. Sadly, insect populations are declining across the globe, which could have some serious consequences for our planet's ecosystem. While increased pesticide use has been blamed for killing important pollinating insects like bees, this week another culprit is being targeted – the common garden leaf blower.

Leaf blowers are a regular fixture in many New Zealand garden sheds. Conveniently removing the physically demanding work of tidying up fallen leaves, they have replaced the simple garden rake and help save time as well as human energy.

Typically, a leaf blower pushes fast-flowing air out of a nozzle, with more powerful models blowing air at more than 300km/h. Some leaf blowers also have a vacuum function that sucks the leaves up through rotating blades and shreds them into an attached bag. While this is all very convenient when it comes to helping a garden to look neat, it is not very convenient for the insects living on or around the leaves. The high-energy air stream can blow insects across a lawn, breaking wings and bodies, while the chopping blades take no prisoners as insects are sucked up, sliced and bagged. Even if the insects manage to survive the wind storm, a lack of overturned leaves and debris in a tidy garden reduces the number of safe shelters that are often home to many insects, removing their protection from birds and other predators.

The high-energy air stream of a leaf blower can blow insects across a lawn, breaking wings and bodies. Photo / 123rf

In recognition of the potential damage that leaf blowers might have on the insect population, this week the German Government issued an official warning statement advising against the use of them.

The country's Ministry of the Environment said that leaf blowers were noisy gardening tools that pose a risk to small animals and insects, citing a recently released report, which warned that an ongoing "insect Armageddon" was threatening all life on earth.

Vilifying leaf blowers is just one of the strategies that the German Government is using as part of its new $170 million action plan to protect insects. Their programme also includes banning the weed killer glyphosate by 2023 and imposing stricter environmental regulations on the use of other pesticides.

While a focus on insects may not seem like an important government strategy while we have a measles outbreak and housing shortage, many scientists believe that insect losses are a serious global issue.

Earlier this year a study in the journal Biological Conservation concluded that 40 per cent of all insect species are in decline and a third are endangered. The consequence of fewer bugs is less food for fish, small mammals and birds, leading to the potential that entire ecosystems collapse from starvation.

Insects are crucial in the human food chain with more than one-third of the world's food supply made up of crops that require pollinating from insects like bees, butterflies and moths.

While we might not like houseflies and cockroaches in our homes, they do serve a crucial function for our planet. Decomposing and breaking down plant and animal waste around us, these less desirable insects work behind the scenes as a silent and efficient waste disposal service.

Leaf blowers aren't the only thing to blame when it comes to insect decline. Deforestation, conversion of natural wildflower-filled land to agriculture and housing, extremes of weather, including droughts from climate change, and increased insecticide and pesticide use are also factors.

However, maybe it's time to help some of our smallest creatures by being a little less tidy with our gardens and letting the insects relax in a more natural outdoor environment.