Last spring on a sunny Sunday morning, thousands of red brown coloured insects circled like a blanket above our lawn. I had never seen them before. They looked like a small kind of beetle with shiny metallic wings that lit up beautifully in the bright sunlight. It was a magnificent spectacle. A few hours later, all the beetles were suddenly gone. This strange event repeated itself over the next few days: in the morning at ten o’ clock the beetles started to fly right above our lawn to disappear again after a few hours. My wife who has a keen eye for nature said: “this looks like a plague to me”. To me that seemed a bit premature and I said: “relax, just look how these beautiful, shiny beetles are flying through the morning sky and reflect the sunlight. Looking back she was totally right. The larvae of these exquisite looking beetles would ruin our turf a few months later.
A search on the Internet revealed the identity of the mysterious beetles. Apparently we were visited by the Phyllopertha horticola also known as the garden chafer, feared among gardeners, breeders and cultivators because of the damage these insects and their larvae cause. The garden chafer has four stages of growth: egg, larva, pupa and adult. In the spring the chafer emerges from its soil-hidden pupa to fly for a few hours each day for about eight weeks. The garden chafer can crawl into the soil to a depth of 10 to 25 centimetres to lay its eggs, from which small larvae will hatch. That’s the reason that these beetles disappear every day after a few hours. The larvae grow into plump, creamy C-shaped caterpillars of approximately 2 centimetres. At first the so-called garden grubs will feed on dead organic material, but in a later phase of their growth they devour plant roots. In July, I observed a discoloration of our lawn. At first I thought, it must be the drought. But the strange thing was that the turf was rolling up like a rug if you touched it. In the previous weeks the garden grubs had nibbled away on the roots and made a clean cut and therefore the grass was no longer attached to its roots.
Nature has many solutions available in different shapes and forms to deal with these little creatures: moles, birds, badgers, they all fancy garden grubs. Our chickens also love them, I have noticed. As soon as they got the chance they look for the dead spots in the lawn and started digging for the fat larvae. From a short inspection of the soil with a spade, I concluded that the population of grubs was almost decimated after a week. The only downside was that the chickens turned our lawn into an even bigger mess and made it look like a piece of farmland.
There is another natural way to get ride of these larvae. A specific nematode, a very small kind of soil worm, can infest the garden grubs and eat them from the inside out. You can buy these “killer” nematodes in many local garden centres and use these as a natural pest control. It’s a good example of what nature has to offer. We just have to become more aware of its clever solutions.
To control red mites, that make chickens and poultry farmers miserable, there’s also a natural remedy. In stead of controlling these red mites with pesticides like (the banned) Fipronil- which led in the Netherlands to 75 million euro’s of damages- these mites can be controlled by introducing predatory mites that eat them. These predatory mites are already available and grown for commercial purposes. Nature has many species that keep each other in balance and suppress plagues. The only thing that needs to happen is that agricultural breeders, cultivators, and gardeners learn to use what nature has to offer.
Sytze Keuning (keuning@bioclearearth.nl)
Published in the journal Bodem.
