Five reasons not to spray the bugs in your garden this summer



File 20171103 26444 1qfv62d.jpg?ixlib=rb 1.1

play4smee/Flickr, CC BY-NC

Lizzy Lowe, Macquarie University; Cameron Webb, University of Sydney, and Kate Umbers, Western Sydney University

The weather is getting warmer, and gardens are coming alive with bees, flies, butterflies, dragonflies, praying mantises, beetles, millipedes, centipedes, and spiders.

For some of us it is exciting to see these strange and wonderful creatures return. For others, it’s a sign to contact the local pest control company or go to the supermarket to stock up on sprays.

But while some bugs do us very few favours – like mozzies, snails and cockroaches – killing all insects and bugs isn’t always necessary or effective. It can also damage ecosystems and our own health.


Read more: The hidden secrets of insect poop


There are times when insecticides are needed (especially when pest populations are surging or the risk of disease is high) but you don’t have to reach for the spray every time. Here are five good reasons to avoid pesticides wherever possible, and live and let live.

1. Encourage the bees and butterflies, enjoy more fruits and flowers

Hover fly.
dakluza/flickr

Flowers and fruits are the focal points of even the smallest gardens, and many of our favourites rely on visits from insect pollinators. We all know about the benefits of European honey bees (Apis mellifera), but how about our “home grown” pollinators – our native bees, hover flies, beetles, moths and butterflies. All these species contribute to the pollination of our native plants and fruits and veggies.


Read more: The common herb that could bring bees buzzing to your garden


You can encourage these helpful pollinators by growing plants that flower at different times of the year (especially natives) and looking into sugar-water feeders or insect hotels.

2. Delight your decomposers, they’re like mini bulldozers

Slaters improve your soil quality.
Alan Kwok

To break down leaf litter and other organic waste you need decomposers. Worms, beetles and slaters will munch through decaying vegetation, releasing nutrients into the soil that can be used by plants.

The problem is that urban soils are frequently disturbed and can contain high levels of heavy metals that affects decomposer communities. If there are fewer “bugs” in the soil, decomposition is slower – so we need to conserve our underground allies.

You can help them out with compost heaps and worm farms that can be dug into the ground. It’s also good to keep some areas of your lawn un-mowed, and to create areas of leaf litter. Keeping your garden well-watered will also help your underground ecosystems, but be mindful of water restrictions and encouraging mosquitoes.

3. An army of beneficial bugs can eat your pests

Mantises and dragonflies are just some of the hundreds of fascinating and beautiful bugs we are lucky to see around our homes. Many of these wonderful creatures are predators of mozzies, house flies and cockroaches, yet people are using broad-spectrum insecticides which kill these beneficial bugs alongside the pests.

It may sound counterproductive to stop using pesticides in order to control pests around the home, but that’s exactly what organic farmers do. By reducing pesticides you allow populations of natural enemies to thrive.


Read more: Even ‘environmentally protective’ levels of pesticide devastate insect biodiversity


Many farmers grow specific plants to encourage beneficial insects, which has been shown to reduce the damage to their crops.

This form of pest control in growing in popularity because spraying can result in insecticide resistance. Fortunately, it’s easy to encourage these bugs: they go where their prey is. If you have a good range of insects in your yard, these helpful predators are probably also present.

Jumping spiders are great at eating flies and other pests.
Craig Franke

4. Your garden will support more wildlife, both big and small

Spraying with broad-spectrum pesticides will kill off more than just insects and spiders – you’re also going after the animals that eat them. The more insects are around, the more birds, mammals, reptiles and frogs will thrive in your backyard.


Read more: Four unusual Australian animals to spot in your garden before summer is out


Baiting for snails, for example, will deter the blue-tongue lizards that eat them, so cage your vegetables to protect them instead. Keeping your garden well-watered, and including waterbaths, will also encourage a balanced ecosystem (but change the waterbaths regularly).

5. You and your family be happier and healthier

Engaging with nature increases well-being and stimulates learning in children. Insects are a fantastic way to engage with nature, and where better to do this than in your own back yard! Observing and experimenting on insects is a wonderful teaching tool for everything from life cycles to the scientific method. It will also teach your kids to value nature and live sustainably.

It’s also a hard truth that domestic pesticides present a significant risk of poisoning, especially for small children.

In reality, the risk of exposing your children to the pesticides far outweighs the nuisance of having a few bugs around. Instead, integrated pest management, which combines non-chemical techniques like cleaning of food residues, removal of potential nutrients, and sealing cracks and crevices, is safer for your family and your garden ecosystems.

Think globally, act locally

Your backyard has a surprising impact on the broader health of your neighbourhood, and gardens can make significant contributions to local biodiversity. Insects are an important part of ecosystem conservation, and encouraging them will improve the health of your local environment (and probably your health and well-being too).


Read more: Conservation efforts must include small animals. After all, they run the world


The ConversationIn the end, insects and spiders are not out to get you. For the sake of our kids and our environment, you should give them a chance.

Lizzy Lowe, Postdoctoral researcher, Macquarie University; Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney, and Kate Umbers, Lecturer in Zoology, Western Sydney University

This article was originally published on The Conversation. Read the original article.

Advertisements

How do we keep gardening in the face of a changing climate?



Image 20170220 15931 v5nf1t
Keep the climate in mind when you’re choosing what to plant.
shutterstock

Andrew Lowe, University of Adelaide

Since 1880, the average global temperature has increased by 0.8°℃, with large changes in rainfall redistribution. With these changing conditions upon us, and set to continue, gardeners will have to alter the way they do things. The Conversation

As climate largely determines the distribution of plants and animals – their “climate envelope” – a rapid shift in these conditions forces wild plants and animals to adapt, migrate or die.

Gardeners face the same changing conditions. If you look at the back of a seed packet, there is often a map showing the regions where these particular plants thrive. But with a rapidly changing climate, these regions are shifting.

In the future we will need to be more thoughtful about what we plant where. This will require more dynamic information and recommendations for gardeners.

The shifting climate

Changes in altitude significantly affect the temperature. As you walk up a hill, for every 100 metres of altitude you gain, the temperature drops by an average of 0.8℃.

Changes in latitude obviously have a bearing on the temperature too. It gets cooler as you move towards the poles and away from the Equator. An accurate rule of thumb is difficult to derive, because of the number of interacting and confounding factors. But generally speaking, a shift of 300 km north or south at sea level equates to roughly a 1℃ reduction in average temperature.

This means that due to warming over the past century or so, Adelaide now experiences the climate previously found in Port Pirie, whereas Sydney’s climate is now roughly what was previously found halfway to Coffs Harbour. The temperature difference is equivalent to a northward shift of approximately 250 km or drop in altitude of 100 m.

At current climate change trajectories, these shifts are set to continue and accelerate.

The plants in your garden might need to change.

Adaptation

Plants are already adapting to the changing climate. We can see that in the hopbush narrowing its leaves and other plants closing their pores. Both are adaptations to warmer, drier climates.

We have also seen some major shifts in the distribution of animal and plant communities over the past 50 years. Some of the most responsive species are small mobile insects like butterflies, but we have also seen changes among plants.

But while entire populations may be migrating or adapting, plants that grow in isolated conditions, such as fragmented bush remnants or even gardens, may not have this option. This problem is perhaps most acute for long-lived species like trees, many of which germinated hundreds of years ago under different climatic conditions. The climate conditions to which these old plants were best adapted have now changed significantly – a “climate lag”.

Using such old trees as a source of seed to grow new plants in the local area can potentially risk establishing maladapted plants. But it’s not just established varieties that run this risk.

The habitat restoration industry has recognised this problem. Many organisations involved in habitat restoration have changed their seed-sourcing policies to mix seeds collected from local sources with those from more distant places. This introduces new adaptations to help cope with current and future conditions, through practices known as composite or climate-adjusted provenancing.

The shifting climate and your garden

Gardeners can typically ameliorate some of the more extreme influences of global warming. They can, for example, provide extra water or shade on extremely hot days. Such strategies can allow plants to thrive in gardens well outside their natural climatic envelope, and have been practised by gardeners around the world for centuries.

But with water bills rising and the need to become more sustainable, we should think more carefully about the seeds and seedlings we plant in our gardens. The climate envelope we mentioned earlier is shifting rapidly.

We will need to start using seeds that are better adapted to cope with warmer and, in many cases, drier conditions. Typically, these plants have thinner leaves or fewer pores. This requires more information on the location and properties of the seeds’ origin, and a more detailed matching of diverse seed sources to planting location.

As the climate changes, we need to be more selective with what we plant.

As the climate continues to change we will also need to introduce species not previously grown in areas, using those that are better adapted to the increasingly changed climatic conditions.
Plenty of tools are now available to help guide seed collection and species selection for planting. These include those offered through the National Climate Change Adaptation Research Facility and the Atlas for Living Australia, for instance.

But these resources are often aimed at expert or scientific audiences and need to be made more accessible for guiding gardening principles and plant selection for the public. The information needs to be intuitive and easy to understand. For example, we should produce lists of species that are likely to decline or benefit under future climate conditions in Australia’s major cities and towns, along with future growing areas suitable for some of our most popular garden species.

This won’t just be useful for a backyard gardener, either. Many exciting new gardening initiatives are being proposed, including rooftop gardens, which promote species conservation, carbon sequestration and heat conservation, and future city designs, which incorporate large-scale plantings and gardens for therapeutic benefits. All of these activities need to take the shifting climate into account, as well as the need to change practices to keep up with it.

Andrew Lowe, Professor of Plant Conservation Biology, University of Adelaide

This article was originally published on The Conversation. Read the original article.