Spiders, Should I get rid of them?
We know there are thousands of spiders living all around us and invariably some of them will find their way into our homes or make themselves at home becoming pests. While they are largely harmless, spiders can make your home a mess and will be a pest to many. So how much do you really know about spiders and their habits, and do we have to live with them in our homes? Let’s explore some common spider species, where they might be hiding, whether they pose a health risk to us, and how we might control them.
What spiders are we likely to see?
While we Wellingtonians, like most New Zealanders have a massive assortment of spiders living in our region most of them will go unnoticed. The exceptions being spiders that either live in our homes or in close proximity to it. The most common ones we will see are;
Black Tunnel Web Spider: These guys can be rather scary looking. They have thick shiny black legs and a bulbous hairy black abdomen. Their head is a shiny reddish brown with large black fangs. Most often it is the males we see wandering about, looking for a mate
Sheet Web Spider: A yellow and brown spider with a fairly skinny body. Whilst they are less common indoors, they will often be found in covered entry ways. Just like the Tunnel Web Spider we see more male Sheet Web spiders wandering around our homes. The largest species of Sheet Webs can have a leg span as big as the palm of your hand.
Grey House Spider and Black House Spider: A lot smaller than the previous mentioned spiders, they are grey and brown in colour and up to 15mm in length. They are most often the culprits for webs in the corner of windows, around exterior lights, and those webs in your car wing mirrors. These poor little guys are also a favourite food source for White Tail Spiders.
White Tail Spiders: Arguably the most revered spider in Wellington. They are black and grey in colour with shiny brown legs, and we can’t forget the white patch at the end of their abdomen that gives them their name. They are nomadic spiders mostly wandering while hunting for food, often in the form of other unfortunate spiders. They will only spin a web when they are laying eggs to protect their young.
Daddy Long-legs Spider. Tiny bodies with disproportionately long legs are the easiest ways to describe their appearance. They will live up in the corners of rooms near ceilings or up in the corners of cupboards. Unlike the well told myth that white tails get their powers from eating these guys. It is closer to the truth to say they are a formidable opponent to white tail spiders and are very adept at catching whatever creature wanders into their webs using their long legs as an advantage.
Where do they live?
Whilst different species of spider have their own preference of habitat, they all have a few common needs; water, food, and shelter. It’s a pretty simple list and our homes and gardens provide all three in abundance. I’ve spent a lot of time under houses and have laid eyes on many different species of spider in the darkness under the floorboards. The sub floor creates a cave like environment, dark and humid mostly. When there is any rubble or old building materials down there Tunnel Webs will love it, and Daddy Long-legs will make a vast array of cobwebs hanging from floor joists and bearers.
Any light source visible from outside your home will draw in flying insects at night supplying a feast for spiders. The gaps and crevices in outside lights is where spiders will build their webs, waiting to ensnare that juicy moth or fly.
Whilst trees and shrubs anywhere on a property will also provide the three staples for spider comfort, it’s when these are close to or up against a house they can create a problem. The branches of plants make the perfect frame to support webs and as with any vegetation there will be an absolute smorgasbord of bugs attracted to them, perfect for many species of spider that lay in wait of their food.
Inside our homes the menu will be a lot less than what is on the table outside. This doesn’t mean there isn’t enough food for spiders, there will always be some sort of bug traversing through your home, and spiders like the daddy long-legs can wait a long time. It’s the species that hunt other spiders or are vagrant feeders that we see moving around more inside, like White Tail spiders. It’s the dark out of reach places inside that most spiders will choose to live, like Structural cavities, wardrobes, and cupboards.
Spiders, the good, the bad and the ugly
For a lot of people spiders are just another thing we live with and are worth having around. Afterall, they catch flies and other bugs, but certainly not all of them. They also play an important part in local ecosystems as tasty morsels for birds and even other spiders. Whilst some people will be stricken with fear at just the thought of a spider.
Arachnophobia is not the only reason we call spiders a pest though. There is also the cosmetic side of having spiders around and the things they can interfere with. Spider webs covering your home are unsightly and they can cause issues with security cameras blocking the camera view with webs. Even some faults in smoke detectors can be attributed to tiny spiders making themselves at home inside them.
We have got a few spiders from our neighbours in Australia and even our native Tunnel Webs look a lot like the Sydney Funnel Web which is extremely dangerous. Though, in Wellington we are lucky we haven’t inherited their deadly spiders. This isn’t to say there is no risk from what we have here, we can however say the danger of a spider bite is low.
Thousands of species can inflict bites to humans and will do so when defending themselves. Spiders bites happen when we handle spiders, they get stuck in our clothing, or when we roll over on them in our sleep. Bites aren’t always painful at the time, but the list of symptoms can be long; minor swelling and itchiness, headaches, nausea, dizziness, and infected sores. Although less common, in some cases these sores are further infected becoming necrotic.
How can we control them?
The good news is we have options to control spiders in and around your home without harming the local ecosystem. With careful selection of treatment agents and the correct application methods we can do targeted exterior treatments to get rid of spiders that live outside and reduce the food availability for vagrant feeders like White Tail spiders. For any spiders living inside we treat selected areas to form a repellent barrier to keep them out. Safe for families and pets, but bad news for spiders.