Portuguese millipedes were accidentally introduced to WA in the late ’80s and their numbers exploded soon after, making them a persistent pest in Perth gardens. Although millipedes are not usually harmful to humans or animals they are a real nuisance when high numbers invade your garden.
Portuguese millipedes (Ommatoiulus moreleti) came from south west Europe and spread through commercial shipping routes all around the world. As they were introduced to Australia without natural predators, the numbers grew quickly and this little black leaf-eater can now be found all around Perth and Australia.
How to identify Portuguese millipedes
Millipedes usually hang around in gardens and leafy areas. Portuguese millipedes are herbivorous, usually found feeding on leaf litter, decaying wood, vegetable waste, and fungus.
Adult Portuguese millipedes grow around 20-50mm long with a smooth cylindrical body, where Australian varieties have a bumpy look. Mature Portuguese millipedes range in colour from slate grey to black, where the juveniles are brown or light grey usually with a darker stripe on each side.
Millipedes as pests
Portuguese millipedes excrete a yellow goo when they are threatened or crushed underfoot. This secretion leaves an unsightly yellow stain on clothes and surfaces, and can be extremely irritating if accidentally rubbed in your eye.
However, the main reason millipedes are considered a pest is their sheer number. When an army of millipedes invades your garden, or enters your home during spring and autumn, they can number in the thousands and be a real pain.
Although Portuguese millipedes have some predators in spiders, beetles, and scorpions, a few hungry predators will not significantly decrease millipede populations. Portuguese millipedes have even been blamed for train crashes in WA and Victoria so it’s important to control these invading pests before their numbers get out of hand.
The most effective way to get rid of millipedes in Perth is to call The Pest Guys. We will personally see to it that your European invaders are sent packing. The Pest Guys millipede control involves an initial pest inspection before we apply a residual repellent barrier spray to all external walls, and outward 2 to 3 meters to knock down the millipede when it tries to come near your home.
We also apply a knockdown product through any leafy or mulched garden beds to ensure a large reduction in millipede numbers. A repellent synthetic pyrethroid dust is applied through the roof void of the dwelling to ensure no breeding can take place inside the roof void.
Portuguese millipedes are one of the few millipede species attracted to light – this is presumably why they visit your home at night. Keeping external lights off is one way to discourage millipede visitors but it will not completely deter them. Reducing leaf waste and decaying wood or vegetables in your garden can help with millipede control by giving them less to feed on.
Once you have a millipede population in your garden, physical barriers like plate glass around the bottom of your house or digging a small moat (yes we’re serious) might slow their advance but will not reduce the population. Some methods like electrified tape or DIY chemical barriers can be incredibly dangerous, even fatal for pets, so we do not recommend trying these approaches yourself.