The Council’s Environmental Health Section receives more complaints about rodents (rats) than anything else. Rats can transmit diseases, their excreta can contaminate food and utensils and they can damage buildings by gnawing conduits and wiring. To check whether rats are around, look for:
• Droppings (12mm to 18mm long).
• Debris such as snail shells with the sides eaten out, almond shells, cape lilac berries, chop bones, etc left in the corners of sheds, under homes and in secluded spots.
• Signs of fruit and vegetables having been eaten.
• Greasy rub marks along paths they travel.
• Burrow holes around buildings.
• Signs of gnawing damage.
• Pet dogs, cats, birds, being more excitable than usual.
• Squeaking, gnawing or movement noises in walls, cupboards and ceilings and under floors.
Rats can be discouraged and controlled by denying them food and shelter. A few simple precautions will prevent or help get rid of them:
• Store firewood away from the sides of sheds and fences and keep it well clear of the ground.
• Regularly remove garden waste or other disused materials.
• Remove fruit and nuts from trees or vines at the end of the season.
• Block holes and other potential access points around all buildings.
• Keep pet food dishes clean and store bulk pet food supplies in a manner that denies access to rats.
• Rubbish bins and compost containers should be well-maintained and free from holes.
• Don’t compost meat scraps.
• Trim trees away from gutters, patios and pergolas.
• Encourage neighbours to remove excess rubbish from their property.
Poison baits are the most successful way of destroying rats. Council’s Environmental Health Section supplies a limited quantity of rat poison for residential premises (but not commercial or industrial premises). If you believe you may have a rat problem, phone Council’s Environmental Health Section on 9272 0648 to arrange delivery of free bait.
The City of Bayswater has almost 10km of river foreshore, some of which contains suitable breeding grounds for mosquitoes. In addition to foreshore areas common breeding sites include roadside drains, septic tank systems, stagnant pools of water in low-lying areas, blocked gutters, pot plants and containers and virtually anywhere else that water pools exist for more than a few days. Mosquitoes can quickly breed to nuisance levels whenever climatic conditions are suitable.
Council’s Environmental Health Section undertakes a mosquito control program in collaboration with adjoining local authorities and the Department of Health to implement the most effective control measures possible. Council’s program focuses on the mosquito breeding season during the warmer months between September and April. At this time of year, particularly after rainfall, mosquito breeding can be high. It is imperative that Council and householders undertake precautions to minimise breeding and prevent being bitten by adult mosquitoes. Council’s mosquito control program includes:
- Monitoring and treating riverside areas.
- Baiting road gullies.
- Monitoring and providing information upon community complaints.
- Treating public areas when they are identified as breeding sources.
- Liaison with neighbouring Local Authorities and the Department of Health on the implementation of mosquito control strategies.
Breeding pools of water are treated with larvicides, which either kill the mosquito larvae or prevent them from developing into adults. Follow up monitoring is undertaken to ensure the effectiveness of the treatments. When mosquito numbers are exceptionally high it is sometimes necessary to fog the general area using adulticides. This course of action is the least effective as it only kills adult mosquitoes but does not prevent breeding. It is also the least environmentally-friendly method of control. Council’s Health Officers also maintain drainage systems in foreshore areas in order to prevent water pooling. Such physical control measures are the most effective way to prevent mosquito breeding.
Mosquito numbers can vary from year to year with about every second or third year being particularly bad. This can be caused by unusual climatic conditions such as the La Nina effect that can create unusually high tides, resulting in semi-permanent pools of water in low-lying river areas. Under normal circumstances, these areas would dry out between tides and hence break the mosquito breeding cycle. These pools are capable of producing continuous breeding, covering several mosquito breeding stages simultaneously. In addition to this problem the increased flushing by tidal action has been found to dilute the active ingredient of larvicides, thereby reducing their effectiveness and longevity. Also, unusually high rainfall periods, particularly when associated with summer storms and “storm surge”, can create higher than usual water levels and increased breeding.
In addition to the foreshore and wetland mosquito control program outlined above, Council officers also treat stormwater drains that hold water. These can cause problems whenever summer rainfall occurs or if sprinkler overspray runs into roadside stormwater gullies.
It is pointed out that a mosquito control program will not completely eradicate mosquitoes but will aim to reduce breeding to levels acceptable to the general public.
Mosquito species that breed around residential properties can be controlled by householders in a number of ways.
1. Prevent breeding around your house
Mosquitoes require stagnant water to breed. Identify and remove all stagnant water sources, (eg. pot plants, cans, bottles, containers, blocked guttering etc.) Make sure fish ponds and swimming pools are not breeding mosquitoes. Fish ponds should be stocked with mosquito larvae feeding fish e.g. goldfish. Swimming pools should be properly maintained and have clean, chlorinated water.
2. Protect your home
(a) Place fly wire on all doors and windows.
(b) Make sure lids are sealed on septic tanks, soakwells and leach drains.
(c) Ensure your sewerage vent pipe has a mosquito-proof cowl and, if it is metal, make sure that holes have not rusted through. Your vent pipe is usually located outside, adjacent to your bathroom or laundry and running up the side of the house and through the roof.
(d) Put fly wire around rainwater tank inlets and overflows.
(e) Cut back foliage which provides harbourage for mosquitoes.
3. Personal protection
(a) Avoid exposure at dusk and early evenings.
(b) Wear loose-fitting, long clothing outdoors.
(c) Use a suitable personal insect repellent.
Should you require further information, please contact the City of Bayswater Environmental Health Section on 9272 0648.
WHITE CEDAR MOTH CATERPILLARS
(Common name: Cape Lilac Tree Caterpillar)
These caterpillars can be a nuisance each year, usually around autumn. Hundreds of caterpillars can invade homes by crawling over paths, walls and inside buildings. The Cape Lilac Tree Moth is a prolific breeder and it is not unusual for a Cape Lilac Tree to have more than 2000 caterpillars feeding on the leaves at any one time. The caterpillars go up the tree at dusk to feed and come down the trunk at sunrise to find a cool, dark place to hide.
The Department of Agriculture has advised that spraying trees for the caterpillar is ineffective, as they are fairly resistant to pesticide. The best method of reducing numbers is to tie a piece of hessian (sacking) around the base of the tree affected. The caterpillars will congregate under the hessian to shelter from the light and heat of the day allowing easy removal and disposal. They can then be placed into an enclosed container and killed using a liberal dose of insecticide or physical means. The tree bagging process may have to be repeated a number of times to reduce numbers to acceptable levels. Hot, dry weather usually kills them off naturally, as does the colder winter weather.
To stop caterpillars entering the house you can use rolled-up hessian, surface sprays or washing powder at doorways and openings.
For further information, contact Council’s Environmental Health Section on 9272 0648 or the Department of Agriculture on 9368 3333.
Bees typically swarm in the spring of each year, prior to establishing new hives. Swarming is part of the natural reproductive life cycle of honey bee colonies. Colonies are stimulated to swarm during spring when warmer weather, together with an abundance of nectar and pollen, provide ideal conditions for the colony to rapidly increase the bee population. Under these conditions, the colony soon becomes overcrowded and is stimulated to reproduce by swarming. The old queen, together with the field bees, leaves the hive and may congregate in trees or shrubs on Council or private property. The swarm will often remain for a day or two while scout bees search for a new home or it may move to another location. Should a swarm decide to settle in your property:
• Keep children and pets inside for half an hour or so, until the flying bees have clustered on to a bush or other object.
• Once the swarm has formed a cluster, usually about the size of a football, and most of the bees have stopped flying, it is safe to go outside and carry on as normal.
• However, keep clear of the swarm until you can arrange to have it removed.
• Always wear footwear to protect your feet.
• Do not put the hose onto the swarm, throw stones at it, smoke the bees out or take similar action. These “do-it-yourself” remedies will aggravate bees, encouraging them to sting in defence.
If you notice a bee swarm or hive on Council property, such as. a public park, right of way or street verge, and you think it may be a public danger, contact the Council’s Environmental Health Section on 9272 0648. Council will send an officer to assess the situation and, if it is considered a danger, a professional pest control operator will be sent to remove or destroy the swarm.
It should be kept in mind that swarming is a natural function of honey bees and, when swarming, the bees are very docile and are not likely to sting provided they are left alone. If the bee swarm or hive is on private property, it is the owner’s responsibility to arrange for it to be removed or destroyed.
Should you have any questions or concerns regarding bees, please contact the City's Environmental Health Section on 9272 0648.
The European wasp is an introduced species that was first detected in Australia in 1959. Since then, it has spread to many parts of the country including Perth. The wasp enjoys the warmer Australian conditions and nests can grow to 3m in length and contain hundreds of thousands of wasps. Because they are attracted to cool drink and meat they are a particular hazard around barbecues and also for pets. If swallowed, they can sting repeatedly (unlike a bee that can only sting once) and cause asphyxiation through swelling.
The European wasp is about the same size and shape as a honey bee but is not hairy. It has distinct bright yellow and black triangle-shaped markings on the body. It is not to be confused with the Papernest wasp that is more slender and has an obvious waste section. The European wasp has long, black antennae, the wings are folded at rest and, when they fly, they hold their legs close to their body.
The European wasp’s nest is always concealed. It is usually underground but can be located inside a hollow tree, a space in a retaining wall or embankment, in a wall cavity or the ceiling space of a house. The nest varies in shape depending on its location but can be very large. It consists of layers of cells and the outside is covered with flaky pieces of chewed up and cemented wood fibre.
The Papernest wasp’s nest, in contrast, is usually small (about the diameter of a 50-cent coin), fully or partially exposed, honeycombed in appearance and is often found on the underside of eaves or hanging off a branch.
Precautions against the European wasp
• Don’t leave food, drink or pet food outside.
• Pick up fallen fruit.
• Ensure that your outdoor rubbish bins have tight-fitting lids.
• Cover compost bins.
• Cover food during a barbecue or picnic.
• Don’t drink straight from a can or bottle when outside – drink from a straw.
• If you see a European wasp leave it alone – it will only attack if provoked.
All suspected wasp sightings must be reported to the Agriculture Protection Board of WA on 9368 3472. Do not attempt to remove the nest yourself as this can be extremely dangerous. Council’s Environmental Health Section can supply more information on the European wasps or assist with the identification of suspected wasps by phoning 9272 0648.