Although spiders can be considered part of nature’s way for keeping insect numbers down, and therefore a good thing, for many spiders can be very scary! Although spiders are generally not aggressive, there are a number of spiders in New Zealand that can give a very severe bite, such as the katipo, redback and white-tailed spiders. Whether you are scared of spiders or not, if you have children or pets, you really don’t want these spiders around the home.
Before we discuss spider control techniques it is important to understand that spiders can be separated into two main types; web-building spiders and running or hunting spiders.
- Web-building spiders (such as the cupboard, redback and katipo spiders) typically build webs and sit waiting for their prey to drop by.
- Running spiders, (such as the white-tailed spiders and huntsman) tend not to have webs and actively hunt for their prey.
Running spiders are the hardest to control (see below) and you will always get the occasional invader. However, with a mixture of spider prevention tips and suitable spider control products you can greatly reduce the chances of an unwanted eight-legged visitor.
GENERAL SPIDER PREVENTION TIPS
- Keeping garden beds and rubbish away from the edge of the house will significantly reduce the spider population.
- If garden beds next to the house are kept in place, it is important to keep vegetation trimmed back from the edge of the house and paths.
- Make sure insect screens and draft excluders are in good repair and well fitting.
- Keep clothes and shoes off the floor to reduce spider hiding places.
GENERAL SPIDER CONTROL TIPS
- The best treatment for web-building spiders is to spray their webs and hiding places with an insecticide (ready to use pump back or aerosol). The key tip to get the best performance is to wait a day or two after spraying before brushing down any webs. This ensures the spiders will have picked up a lethal does of insecticide (by walking on the web) and by using a brush (rather than hose), you can ensure the insecticide remains in place to prevent new spiders taking up residence.
- To prevent web-building spiders take up residence in the first place, spraying around doors, windows and vents, as well as under eaves and guttering delivers excellent results. As these spots tend to be sheltered from sun and rain, the treatment can last many months.
- It is a lot more difficult to prevent running spiders entering the home. Carrying out a preventative spray around the perimeter of the home and any openings will have some benefit, although running spiders often walk on the tips of their legs, preventing them from picking up a lethal dose of insecticide. However, if you carry out a preventative treatment for web-building spiders and other insects, the numbers of running spiders will be greatly reduced, as there will be little prey for them to feed on.
- Even with the best control program the occasional spider may get in. A crawling insect aerosol should be kept on hand to spray the occasional unwanted spider. Ensure the spider receives a good dose and keep your distance!
Let’s have a look at specific tips for the key pest spiders:
WEB BUILDING SPIDERS
The kapito is a New Zealand native. As it is an endangered species, it should not be killed and indeed there are significant penalties in place if you do carry out a treatment for katipo spiders. However, as they are rare and generally only found in coastal sand dunes, they are not an issue for most homeowners.
The redback spider, which looks very similar to the kapito is an introduced pest from Australia. Currently, it is still confined to limited areas, primarily around Auckland and also in central Otago. Spraying around the exterior of the home in cracks and crevices, long fencing, under furniture and around barbeques. Inside the home they do like down lights, so keep an eye out for spiders falling from the ceiling!
Also known as the false katipo, this spider came from South Africa and is now widespread in New Zealand. It’s colour varies from black to dark brown, with only very feint red markings to the rear most part of the abdomen. They do tend to build webs in undisturbed areas indoors (thus their name) and can be targeted with a direct spray.
GREY HOUSE SPIDER:
A grey / black spider up to 2.5 cm long, with a feint pattern on the abdomen. Typically builds webs around windows, doors and eaves, often with a funnel like entrance. Direct treatment of the web and into its hiding place gives excellent results.
RUNNING OR HUNTING SPIDERS
This spider is easy to identify. They are a slender spider up to 2.5 cm long with brown and black striped legs, with a white tip to the abdomen. Their favourite food are other spiders, so an exterior treatment for web-building spiders will make your home a lot less attractive to white-tailed spiders.
These large, fast moving spiders have been introduced from Australia. Although large in size, that are quite timid (unless guarding an egg case) and their bite is not considered dangerous. Keeping other spiders and insect numbers down will reduce huntsman numbers. If you’re not happy about catching and releasing a huntsman, have a spider or crawling insect aerosol on hand for the occasional invader.
Both white tailed and huntsman spiders will come into the house “by accident”, either looking for prey or to escape the heat in summer. They normally live under bark and rocks, so do like hiding in sheets and clothes left on the ground. So keeping your house tidy will help avoid any nasty surprises.
So with a bit of garden maintenance (keeping plants and rubbish away from the perimeter of the home), sealing potential entry points and a good exterior pest spray once or twice a year, you can keep spiders at bay… and arachnophobes can certainly sleep a lot easier at night.
PESTXPERT HAVE ALL THE TOOLS YOU NEED TO CARRY OUT A SPIDER TREATMENT
Specialist Spider product to target spiders where they hide and spray from a distance
Outdoor treatments are ideal to prevent web-building spiders