Now part of the Australian environment, Portuguese Millipedes belong to a group of animals which have many body segments, each with 2 pairs of legs. Millipedes are vegetarians eating soft, rotting vegetation, so playing a part in the formation of nutrient enriched soil. Although various species of millipedes occur in temperate climates, and we do in fact have several native species in South Australia, it is the introduced millipede which has become a pest. They are attracted to lights at night, invading homes, often in plague proportions. Because they do not breed inside, they usually die.
Habits and Habitats
- Millipedes originated in Portugal and Spain and were introduced to Australia by accident in 1953, first appearing in Port Lincoln.
- Millipedes do not walk far, adults only moving a maximum of several hundred metres a year.
- Invasions occur in spring and autumn, though the autumn invasion is more intense for a longer period of time.
- Mating occurs during autumn, during which time, the adults are moving around on the surface.
- Millipedes that invade houses, have bred within 100 metres of the house.
- Millipedes disperse further afield when transported in soil and woodchips.
- For the first year, millipedes are small and often overlooked. They do not invade houses until they are about 2 years old.
- Millipedes breed in leaf litter, preferring places where plants cover the ground completely. Soursobs and Salvation Jane form the perfect canopy for millipedes. They do not like lawns, cultivated areas or bare ground.
- Millipedes secrete a pungent yellowish secretion when agitated. This secretion is composed of organic chemicals called quinones that make it distasteful to predators. Squashing the millipedes will also release this chemical along with the unpleasant odour.
What can be done to repel Millipedes?
- Closing curtains at night will reduce the attraction.
- Clearing leaf litter and dense undergrowth will destroy any attractive breeding sites.
- Chemical barriers can be applied by qualified pest consultants. The approved chemical treatment is harmless tohumans when applied according to regulations, and it does not persist in the environment. The effectiveness of the treatment lasts for several weeks.
- Millipedes cannot cross smooth, clean, vertical surfaces. It is possible to build a moat into which millipedes fall with no way to get out. Forced to walk the only direction possible, they fall into a container trap.
- Smooth plate glass set into concrete around the perimeter of the house prevents millipedes from gaining a foothold in order to enter a house. These must be kept clean and free of litter for them to be effective.
- A light trap effectively reduces millipedes by 90%. This is a box with a 5 watt globe in it, a slot opening on the side and a base treated with the right chemicals, effectively lures the millipedes to their death.
- While millipedes do not carry any known diseases, they are a nuisance pest.