Beneficial insects, your best defence against bugs

mantis | she cooks, she gardens

I’ve spent a bit of time bagging out bugs over the last few weeks because, lets face it, they aren’t really all that helpful in the garden. But what if I told you that there are some bugs that are actually good for your garden and that we should be doing all that we can to attract them?

One of the biggest reasons I try to avoid using chemicals in my garden is because they are so non-discriminatory. When I first started gardening I was overly zealous with the trigger pack of ‘insect spray’ I picked up at the nursery after finding my chili bush infested with aphids. I had no idea the damage I was doing to the precious eco-system already thriving in my small garden, and would often find myself spraying as a protective measure. Then one night while I was spraying I saw a large mantis crawl up from underneath a leaf I had just coated in pyrethrum spray. It was not looking very happy with me at this point, and it suddenly dawned on me just how problematic this kind of indiscriminate spraying was.

Beneficial Insects

Mantis (pictured at this top of the post) are part of a group of bugs known as ‘beneficial insects’, which means they feed on insects like aphids and mites and help keep them under control. In nature, in a thriving eco-system, insect and indeed animal populations are kept under control by the predator/prey relationship. Where this balance is thrown out, as it usually is where chemicals are used, you end up with infestations and no way to manage them.

One way to correct that imbalance is to try as hard as you can to stop using chemicals in your garden and focus on encouraging these insects back into your garden. This will mean that you’ll need to find other ways of controlling problem insects until you’ve restored that balance and some of these are explored over on this post.

Ladybug instar - an aphid eating machine.

Ladybug instar – an aphid eating machine.

This is a ladybug larva which can eat hundreds of aphids in a single day. I found him crawling around on another plant in the garden and brought him over to one of the chili bushes that currently has a small aphid problem.

After a couple of minutes of exploring he found this small population of aphids and set about feeding on them. Pretty cool, hey?

Soon he will attach himself to the plant and pupate, and later hatch as a hungry little ladybug who will go on to lay more eggs and start the cycle over again.

Ladybug Pupa

Other beneficial insects to keep an eye out for are hoverflies, lacewings and parasitic wasps.

How to encourage these ‘good bugs’ back into your garden:

Well, as previously mentioned, stop spraying chemicals! You never know what you will hit if you spray with reckless abandon.

Investigate other methods for keeping insects under control that won’t harm the ‘good bugs’ – for example, spraying aphids off of leaves with the garden hose or warm soapy water, burying a snail trap and picking off caterpillars when you see them.

Dill, when left to flower, is incredibly enticing to beneficial bugs like lacewings and hoverflies.

You can buy a pheremone lure to hang in your garden which will help lure the little critters to your patch, it releases an attractive aroma over the period of a few weeks and is completely safe and non-toxic.

Another way to go is to let some of your plants go to flower and plant one pot of plants that are there as beneficial insect food. Herbs such as dill and cilantro (coriander) are particularly enticing to predatory insects when they are left to flower, as are common floral favourites such as Sweet Alyssum, Cornflowers and Californian Poppies. I bought a beneficial insect seed mix online for a few dollars and spread it around the garden. It’s well worth it, the added benefit being that you get lots of lovely flowers.

Thanks for reading, I hope you’ve found this post helpful. Do you have any tips on how to encourage more good bugs to your garden?

8 Comments

  • Another great garden post Erin! I put some laminated butterflies in the garden yesterday and bought one of those yellow sticky things on the weekend. Fingers crossed they help.
    I try to keep a few flowers around but I really should plant some more.

    • Erin B says:

      Thanks Claire, I’m really excited to see if your new additions to the garden will make a difference – especially those laminated butterflies, they look much prettier than my daggy bread tags.

      Flowers are great, even better when they are edible. I have to remind myself to leave room for them too. 🙂

  • louia says:

    I dont have many ladybugs in my garden – try to put them on my roses if I find them in the pool. How can I get some to start my own colony? Can you buy them?

    • Erin B says:

      Hey there, your best bet would be to try some of the things I’ve suggested above like cutting out the use of chemicals, letting some of your herbs go to flower, and perhaps experimenting with a pheremone lure to attract more to your garden.

      It is possible to buy ladybugs but if you’re using chemicals then you’ll find it hard to maintain the population. The critters will need food once they arrive so you’ll still need to make sure the environment is something they’ll want to stay in otherwise you’ll just be wasting your money.

      Best of luck!

  • This is a very timely post Erin, I discovered some aphids on my kale bushes and have been contemplating spraying them but held off and now I’m so glad I did! x

  • Nick says:

    I haven’t sprayed for 8 years and have a wonderful, diverse range of predators and helpful birds that keep pests at bay.
    Having a bio-diverse environment, companion planting, crop rotation and healthy soil has attributed a well balanced eco-system. Happy gardening to all. Nick

  • Your photos are absolutely stunning!
    We definitely need more flowers in our veggie patch. Might have to go and get some on the weekend.
    the grasshoppers are the bane of our patch – or they were last year. We just plucked them off and fed them to our chickens, who thought all their Christmases had come at once 🙂

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