These are a home owner's worst nightmare. I can think of nothing worse than having a few friends sitting around a meal table with millipedes raining down from the ceiling. Believe me, I have experienced this nightmare myself. These invasions seem to occur in the spring, autumn and after heavy rains. Thousands of migratory millipedes can create a mess. Once they die, expect a smell that can last for several weeks. They are attracted by lights at night.
IDENTIFICATION
They are slow crawling, appear to have hundreds of legs and generally light brown in colour and black in the adult stage. During the autumn the adults move along the surface and mate.
The eggs are laid in clusters of 100 to 200 in the soil and usually hatch in about three weeks. Females can lay up to as many as 300 eggs a year. The newly hatched millipedes resemble adults but only have seven segments and 3 pairs of tiny legs. They will moult many times adding segments and legs. When they are mature each body segment has two pairs of tiny legs. Most species take 1-2 years to reach reproductive maturity.
They love to live and hide in undisturbed decomposing material, leaves, mulch and anything that's moist. Millipedes will get nutrition from these locations. When they breed, the eggs hatch and larvae will start feeding right where they emerge. This leads to large populations or nests which can be in the hundreds. Millipedes will remain feeding as long as there is a food source to support the nest. This could be for a year or two but at sometime you can expect a migration.
Excessive rain, drought or lack of food will cause them to migrate to a new feeding area. This incidence can occur at any time of the year after rain and could result in several thousand moving in a direction that is right in line with your home. Other infestations have led to thousands collecting at the base of a wall or climbing the side of a house.
The migrating millipedes will reach a certain height and simply come to a stop. We are not sure why they do this but it will lead to massive numbers accumulating and a nasty smell when they die. Their bodies contain rows of glands that secrete a pungent yellowish secretion when they are disturbed by preditors (birds) which is distasteful to them.
PLANTS ATTACKED
Millipedes will eat mosses, pollen. They have been known to eat the soft parts of Sweet Corn, Tomatoes, Cucumbers, Squash, Melons, Strawberries, some root crops such as Parsnips, Turnips, Potatos, where they have decaying parts.
CONTROL
Controlling Millipedes will involve a series of important steps.
Step one is to identify where the nests are. This will allow you to minimize the conditions the millipedes need and help control the amount of pests moving inside the buildings. Look to see where they are invading from. In most cases, you will find them living along one side of the garden or wall of your home. Look around this area of the property. Inspect nearby areas where there is a thick coverage of grass growing, mulch, compost heaps, wood heaps, large rocks, pea straw, bark mulches, garden sheds, cracks in cement paths or driveways. Each of these locations can breed, feed and shelter millipedes.
If you know where they are coming from, you will be able to treat the area and correct the excessive organic matter available for them. Clean up leaves and replace old straw that is decomposed. Move wood piles away from the house. Seal cracks in cement so as not to allow water to gather. Rake away the thatch build-up from your lawn areas. Reducing these ideal millipede conditions, you take away the food and harborage these pests need for their survival.
Once you have finished step one, you can treat the problem. Millipedes do not have a wax coated body, so when they are exposed to the dry they will die.
Step two is deciding which method of control you need to implement to stop the invasion. Millipedes are not insects. If you want to stop them quickly and keep them from getting into your home, use a product called LIQUID CARBARYL. REMEMBER Carbaryl is toxic to humans if inhaled, read the safety directions on the container before using.
Treating the outside walls will keep them from coming into the buildings. Be sure to treat the walls by spraying a good coverage at least a metre up from the ground or go as high as you have seen them crawling. This will kill what is there and stop new ones from reinfesting. It is most common that one or two sides of the house will have the most activity. Be sure to concentrate your efforts here.
Millipedes like to live adjacent to the foundation, it is recommended that you treat the ground around the home as well. Watering after you spray will help the product to sink down and work its way deep to where pests may be feeding.
REMEMBER that the protective coating of spray on the walls will only last a limited time and less when the walls are exposed to the wet weather.
Step three is the ongoing maintenance of watching and making sure you minimize nest locations. By stopping the nests from developing, you are stopping the invasions which would undoubtedly follow. In most cases, homes which experience migrations are more likely to have it happen again.
A lot of people tend to think this is a one off occurrence. The fact of the matter is that millipedes take a long time to develop. This period of development may taken several years before enough have matured. Once they begin to move and relocate or die, the cycle is forced to start again. Don't expect to see any for a year or more. However, next time could be a lot worse if they are left untreated.
SUMMARY
Millipedes are not insects but are considered serious pests. If left untreated, populations can build up and lead to mass migrations. These migrations can infest your home with messy, smelly dead bodies that seem to get everywhere
