General Pest Control

Contents

A pest is destructive, sometimes noxious and often troublesome.

Pests require food, shelter and security. Denial of these environmental factors will prevent their survival and is the first line of defence against possible infestations. Environmental control can be achieved by denying the pests:

  1. Access—through care in the design, maintenance and proofing of buildings. Doors, windows and screens must be kept closed to prevent entry
  2. Food and places for them to hide – by good housekeeping.

Rats & mice

Rats and mice are a nuisance. They are known to damage food and property and are responsible for spreading disease either:

  • Directly – by contaminating food and belongings with urine and droppings (e.g. Salmonellosis and Leptospirosis)
  • Indirectly – by their fleas and mites (e.g. the plague and typhus). They are mostly nocturnal animals and are rarely seen during the day. Droppings, gnawing, burrows or tracks will alert you to their presence.

Mice tend to live inside where it is warm and dry and rarely stray more than a few metres from their nest. They prefer to feed on grains, cereals and other dry goods. Rats generally nest outside under buildings, in piles of debris or in overgrown parts of the section. They range further than mice and will feed on almost anything including meat, fish and rubbish.

Obvious signs of infestation are droppings. Rodents may gnaw holes in doors and walls. These holes show distinct grooves and tooth marks.

Control methods

Keep your grass short and remove weeds. Keep compost bins tidy, remove leaf litter, fallen fruit and rubbish regularly. Mice can fit through a gap 12mm in diameter.

Poisoned bait is available from garden or hardware shops. Follow all instructions and warnings and always wash your hands thoroughly after handling it.

Tips to remember when using bait:

  • Place the bait where the rodents are active, such as in the ceiling cavity, under the floor, in the garage
  • Always put bait out of reach of children and pets
  • Make a bait box - put the bait under an upside down (ice cream) container with small holes cut in opposite sides for the rodents to gain entry, and a weight on top to stop it blowing away or being knocked over. A length of 80mm or 100mm drainpipe also makes a simple bait box for outside
  • Leave bait down for at least two weeks after the rodents seem to be gone.

Traps can be used. Rats are a little more cunning and tend to avoid traps. Traps are best located in areas such as burrow entrances or along their track ways. You need to check them daily and reset those that have been successful.

Flies

Many flies are a threat to health and are a nuisance to humans and animals. Blow flies, house flies, fruit flies and other species of flying insects are major pests of homes, farms, shops, factories and other urban and rural places of human habitation.

Control methods

To prevent flies from accumulating, clean up food waste immediately. Deny access to breeding sites by using tight fitting lids on rubbish bins. Fit fly screens to prevent access inside. Insecticidal sprays and dusts may be applied to breeding sites.

TIP: Clear coffee cups and beer bottles as they are attracted to this type of food. REMEMBER INSECTICIDES CAN BE HARMFUL. ALWAYS USE AS PER MANUFACTURER'S INSTRUCTIONS.

Spiders (in particular white tailed spider)

These spiders live in gardens, inside houses, beneath bark and rock, and are found in the folds of clothes, towels and inside shoes. The bite of a white tailed spider is normally harmless but occasionally they can result in a deep ulcer of skin necrosis (where the area of skin around the bite dies). White tailed spiders are 12mm to 17mm long and they make a zigzag type web.

Control methods

  • Vacuum regularly
  • Remove noticeable webs
  • Fill in gaps in walls and under doors to deter entry
  • Remove sheltering sites like firewood piles and compost piles from near your home
  • Use lighting in a way that is less attractive to the insects that spiders feed on

Magpies

Magpies display aggressive territorial behaviour that makes them pests.

Magpies have a complex social system in which individual magpies may occur in non-territorial flocks or territorial pairs. Magpies defend their territory by singing, aggressive posturing and fighting. It is this aggressive territorial behaviour that makes magpies a pest.

Magpies attack and occasionally kill other birds. Although magpies have been known to attack native birds, this is an insignificant threat compared to the problems imposed on our native birds by mammal pests.

This territorial behaviour is also a nuisance to local residents. Numerous reports have been received of magpies attacking children, cyclists, farmers and runners. These incidences increase during the breeding season from early July through summer.

Control methods

Using a variety of control methods will provide the best result.

Many traps are commercially available including Larsen traps, The Arcane™ magpie trip-trap, letterbox traps and adapted possum cage traps. These are all live capture traps that allow non-target birds to be released unharmed.

The Larsen style trap is very popular. It is a double caged trap with a flap door held open by a false perch which, when triggered, falls down, releasing the flap and trapping the bird. A decoy magpie is placed in one side of the trap to attract others to it. The Larsen trap is most effective during the breeding season (July though summer???not sure what this means. ), as magpies are particularly territorial at this time.

Pigeons

The bird's excrement causes paths, roofs, and playgrounds to become smelly, unsanitary and slippery. Pigeons roost in roof spaces and under bridges, and their excrement can block drains, damage buildings, and also damage car paintwork. If their population goes unchecked, they may become more of a problem and begin nesting on buildings or private property.

Slippery paths and build-ups of pigeon excrement are a hazard to the health and safety of members of the public.  The birds' excrement also has the potential to transmit many diseases.

Control methods

Scaring: As no distress call has yet been isolated, scaring with auditory or visual systems is rarely successful for long.

Proofing: Many systems are available, but great care must be taken with choice of bird proofing product for each part of the building. Bird netting with 50mm mesh is the most successful method.

Control: Can be a good option for removing specific individuals; large-scale culling is rarely successful for long and incurs very significant adverse public reaction. Removal of food and shelter will help.

Rabbits

Rabbits are a major agricultural and garden pest in parts of New Zealand. They reduce farm stocking capacity, contribute to erosion by burrowing, damage newly cultivated lawns by scratching the loose soil or eating new growth, and damage vegetable gardens and ringbark small trees and shrubs.

The European rabbit was introduced to New Zealand as a food source and hunting resource in the 1860s. Females can produce 20 to 30 young each year, though only about 10 per cent of juveniles survive to six months of age. Rabbits are now widespread throughout the Ashburton District in varying numbers.

Control methods

By integrating a variety of control methods you will have a better outcome than relying on only one control method.

Night shooting is probably the most common form of rabbit control in New Zealand and can be effective in controlling light infestations. To be effective, be systematic. Shooting to control medium or high rabbit numbers has limited effect on the population and surviving rabbits will become 'gun-shy'. Poisoning is the more cost-effective method for larger numbers.

Pindone™ rabbit pellets: Pindone™ is an anticoagulant poison originally developed for rodent control. Rabbits are particularly susceptible to Pindone™, while cats and dogs are five to six times more resistant and humans 100 times more resistant. This makes Pindone™, when used correctly, safe for urban areas. Follow the manufacturer's instructions and keep bait containers in cool and dry locked cupboards. Pindone™ is slow acting and the rabbit must consume baits over several days for it to be effective. Accidentally poisoned domestic pets should be taken to a vet who will administer Vitamin K1, an effective antidote.

Using Pindone™ with bait stations.

Bait stations must be used. Bait stations must:

  • be safe for humans
  • be inaccessible to non-target animals, such as dogs
  • protect baits from rain.

Examples of suitable bait stations include the Greengard Eco bait station and modified Philproof bait station. These bait stations are also suitable for possums and rodents.

For large numbers of rabbits, increase the number of bait stations and spread them through areas containing rabbit sign. For help with correct bait station placement, refer to bottom of page.

Trapping can be time consuming, requires knowledge of correct trap placement to prevent catching other animals and is not recommended unless you already have some trapping experience.

Feral cats

Feral cats are domestic cats that have gone wild or have been bred into the wild. They often look scruffy and may be very wary of people. Cats prey on birds, lizards and frogs, including many native species. Cats can carry tuberculosis, toxoplasmosis and parasites which are harmful to humans.

Feral cats live in a wide range of habitats throughout Ashburton District. They are very territorial and have home ranges from 30 hectares to 80 hectares in size. Feral cats are mainly active at night.

Control methods

Feral cats are naturally cautious and can be difficult to trap. Live catch traps, such as box and cage traps, are suitable.

As cats are more active at night, set your traps at night and release them in the morning if nothing is caught. This is a good safety measure if you have domestic cats around, as you only need to keep them inside during night hours.

Wire your traps open for a couple of nights so the cat gets used to entering it, then set it to catch. Bait the traps with fish, fresh meat or cat food. Once trapped, a feral cat should be disposed of humanely. Check with the SPCA for approved methods of destruction in your area.

Shooting (in rural areas only) may be effective provided the animal is killed on the first attempt. This is because a feral cat will quickly escape and be very wary from then on. Talk to your family and neighbours and advise them to keep pets inside if this option is suitable for your area. It may be a good idea to put high visibility collars on your domestic cats.

Commercial pest controllers

For assistance with all pests mentioned in here, pest control contractors can be found under 'pest control' in the Yellow Pages.

Page reviewed: 17 Jul 2015 3:05pm