Little Helpers are Swarming In
As the days get warmer, colourful Ichneumon Wasps become a common sight in many Aussie backyards, hovering above your lawn on a warm day or trying to mate with your orchids.
These striking, stingless insects are Mother Nature’s pest control for your garden and provide fascinating entertainment for those prepared to sit still and watch the show.
At up to 12 cm in length and with bright markings, these wasps are easy to spot as they go about their business. About now they will be searching your backyard for a suitable host for their eggs. Ichneumon Wasps are parasitoids, meaning they lay their eggs on a host insect, such as a moth caterpillar or lawn grub. The wasp larvae hatch and feed on the insect, and unlike fleas and lice they will eventually kill their host.
So if you see them about now hovering above your lawn and garden beds, you know they are seeking out any grubs that might be munching on the roots of your plants. Watch them at work, and if you want to return the favour, plant plenty of flowering natives in your backyard.
The adult wasps feed on the nectar, and the more sugary goodness they get, the more eggs they will lay. Be sure not to use insecticides as a poisoned host will also kill the wasp larvae. If you still find that your grubs outnumber your wasps and if water restrictions allow, try flooding the affected area. The grubs will come to the surface and the birds will soon clean them up.
You might also observe your wasps trying to mate with your orchids. Look closely and you will see a striking likeness between some orchid flowers and the Ichneumon Wasp. It is your orchids trick to entice the wasp to pollinate it.
The flowers of Hammer Orchids Drakaea and Flying Duck Paracaleana in southwest Australia and Caleana in southeast Australia have developed flowers that attract an inexperienced male and dust him with pollen.
In temperate areas of Australia, the native Slipper Orchids Cryptostylis even mimic the perfume of the female wasp and lure the male with pheromones and looks. Add an orchid or two to your backyard and witness nature at its best, even on the smallest balcony.