Spiders and flies
Auckland spider and fly control that starts with which spider it is
The calls we take about spiders come in three kinds. Webs that are back on the eaves and around the window frames a few days after they were brushed off, a large, fast spider crossing the lounge wall on a late summer evening, or a white-tail turning up in a towel or a pile of washing. Those are three different animals with three different answers, which is why we ask what you have seen before anyone talks about spraying.
Ask about spiders and flies
Tell us what you have noticed and we will put a price in writing.
Monday to Friday 7.30am–6pm, Saturday 8am–2pm. Urgent wasp work is prioritised.
Spiders and flies in Auckland, in brief
Most of the spiders on an Auckland house belong to two introduced web builders, the grey house spider and its black cousin, and treating the eaves, window frames and fences they web is what brings the rest down, white-tails included, because white-tails hunt them. A treatment lowers numbers for some months rather than ending them, flies are fixed at their source rather than sprayed, and New Zealand's two venomous spiders do not live in house eaves.
So identification comes first, and we are honest about what follows from it. We will tell you which spider you have and whether it needs treating at all, since an Avondale spider on the wall or a daddy long-legs in a ceiling corner usually does not, and what a perimeter treatment can realistically do, which is cut the numbers down for a season rather than make the house free of spiders.
Which spiders are on your house, and which ones matter
The webbing on eaves, window frames, fences and car mirrors almost always belongs to grey house spiders (Badumna longinqua) or black house spiders (Badumna insignis), two species that came here from Australia, and these are what an exterior treatment is aimed at. The loose tangles in ceiling corners indoors are usually daddy long-legs (Pholcus phalangioides), which are harmless and better removed with a vacuum than a spray.
Of New Zealand's roughly 2,000 spider species, over 90% are endemic, yet Manaaki Whenua notes that the ones we see around houses and gardens are mostly introduced. Several build no web at all. The white-tail (Lampona murina in the North Island) hunts other spiders at night, preferring grey house spiders, so a house with fewer webbing spiders tends to have fewer white-tails as well. Vagrant spiders (Uliodon) are fast, dark garden hunters whose males wander indoors in autumn looking for mates. The Avondale spider (Delena cancerides), a very large and entirely harmless huntsman, has stayed close to Avondale since it arrived in the 1920s, and its males come inside between January and March.
That leaves the two that matter for safety, and neither lives in your eaves. The katipō lives on coastal sand dunes as a native species, and the Australian redback is established in parts of Central Otago. We have set out how to tell a katipō from a redback and the false katipō, which is the shiny black spider most people actually find in a shed.
What a spider treatment does, and what it cannot
A residual product applied to the surfaces web-building spiders use keeps acting on contact for a while, which in our experience means a few months, and less on walls that bake in the sun or take the rain. It reduces the web builders on treated surfaces most of all. Hunting spiders that never sit in a web, and new spiders walking in from gardens and reserves, fall more slowly, and no treatment makes a house spider-free.
Webs and egg sacs are brushed down before anything is applied. Product that lands on silk is largely wasted, and an egg sac left in place can hatch after the treatment has faded. Two things around the house matter almost as much as the product: outdoor lights, which gather the moths and flies that spiders feed on, and shrubs or climbers touching the cladding, which give new spiders a bridge straight onto the walls.
We do not offer a guarantee period, because how long a treatment holds depends on your walls, your lights and your garden more than on us. What we will do is tell you the interval that is realistic for your house, and say so when a repeat treatment would not be worth paying for. If you would rather do it yourself, our guide to when to spray for spiders, and which products last covers timing, product types and surfaces.
Flies: which fly it is decides the fix
Flies in a house come from one of three places, and spraying the house does little about any of them. House flies breed outside, in bins, compost heaps and dog droppings. A sudden burst of metallic blowflies in one room usually means something has died close by, often a rat in a wall or ceiling. Slow grey flies on sunny upstairs windows in autumn will be cluster flies, whose young develop in lawn earthworms, not indoors.
Blowflies are a carcass problem first. Once the source is found and removed the flies stop coming, and until then no treatment holds them; if there has been rodent activity, the rodent is usually the real job, which our rodent control page covers. Cluster flies are a timing problem. They look for a roof space or wall cavity to spend the winter in, so the work is done on the roof space and the sunny exterior walls before they arrive, as we explain in why cluster flies fill the same windows every autumn.
House flies are fixed at the source: bins with closed lids kept away from the doors, compost covered, pet waste picked up, fly screens on opening windows, and only then a residual treatment on the surfaces around doors and bins where flies rest. Flies and spiders are connected, too, because the insects drawn to a lit window are what keep the webs around it busy. For commercial kitchens, documented fly management is quoted separately.
Identification
Spiders and flies around Auckland homes, and what each one means
| Species | Size and look | Where you find it | What it means for you |
|---|---|---|---|
| Grey house spider, Badumna longinqua | Body up to about 15 mm, grey, legs banded with hairs | Lacy webs around a tube-shaped retreat on eaves, window frames, fences, car mirrors | The main target of an exterior treatment, and the white-tail's food |
| Black house spider, Badumna insignis | Body 12–18 mm, robust, dark brown to black, white marks on a charcoal abdomen | Lacy sheet webs around a retreat in crevices, brickwork and window frames | Treated with the grey house spider; a painful bite if handled |
| White-tailed spider, Lampona murina | 12–17 mm, slim and cigar-shaped, dark grey, white tip on the abdomen | No web; hunts at night, shelters in clothing, towels and bedding | Falls when house spiders fall; the bite is painful, not flesh-eating |
| Daddy long-legs, Pholcus phalangioides | Body about 8 mm, pale and translucent, legs five or six times the body length | Loose tangles in ceiling corners, garages, behind furniture | Harmless; a vacuum does more than a spray |
| Vagrant spider, Uliodon | Dark brown to almost black, legspan about 50 mm, very fast | Garden hunter; males wander indoors in autumn | A seasonal visitor; a single bite is on record |
| Nursery-web spider, Dolomedes minor | Pale brown or grey, yellowish stripe, legspan 60 mm or more | Dome-shaped silk nurseries on gorse and shrubs | Outdoors only; leave it |
| Avondale spider, Delena cancerides | Flat huntsman, legspan up to 200 mm | Avondale and its neighbours; males indoors January to March | Harmless; no treatment needed |
| False katipō, Steatoda capensis | Glossy black to dark brown, white abdominal marks, no red hourglass | Houses, sheds, gardens and beaches nationwide | The usual katipō found at home; a painful bite, not a dangerous one |
| Katipō, Latrodectus katipo | Female body about 8 mm, pea-sized black abdomen; usually all black in the northern North Island | Sand dunes on the coast, beneath driftwood and among beach grasses | Venomous and protected by law; never treated, leave it alone |
| Redback, Latrodectus hasseltii | Black with a red stripe down the back | Established in parts of Central Otago; occasional finds in imported goods | Venomous; a find in imported goods is reported to MPI |
| House fly, Musca domestica | 6–7 mm, grey, four dark stripes on the thorax | Bins, compost, pet waste, kitchens | Fixed at the breeding source |
| Cluster fly, Pollenia | About 8 mm, dark grey and not metallic, golden hairs on the thorax, sluggish | Sunny upstairs windows in autumn; roof spaces and wall voids | Never breeds indoors; treated before autumn |
| Blowflies, Calliphoridae | Shiny metallic blue or green, usually bigger than a house fly | A sudden burst at one window or in one room | Usually a dead rat or bird nearby; find it first |
How we do it
How a spider or fly job runs
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We identify what is actually there
House spiders webbing the eaves, white-tails hunting them, a seasonal vagrant or Avondale spider, or flies with a source outside. Each has a different answer.
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We brush down webs and egg sacs first
Product sprayed onto silk is wasted, and an egg sac left in place hatches after the treatment has done its work.
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We treat the surfaces they use
Eaves, soffits, window and door frames, downpipes, decks and fences, with a residual product applied to label directions and kept clear of ponds and flowering plants.
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Inside only where it earns its place
Skirtings, wardrobes, the garage and the roof hatch, and the roof space itself for cluster flies. Living areas are not sprayed by default.
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We tell you what keeps them coming
Outdoor lights, planting against the cladding, where the bins sit, and how long the treatment can realistically be expected to last on your walls.
Cost
What a spider or fly treatment costs
| Job | What it covers | Indicative |
|---|---|---|
| Exterior spider treatment | Standard house: webs and egg sacs brushed down, then eaves, soffits, window and door frames, decks and fences | $190 – $290 |
| Interior and exterior | Exterior perimeter plus skirtings, wardrobes, garage and the roof space hatch | $310 – $420 |
| Fly treatment | House fly or cluster fly work: roof space, sunny wall voids, window frames and bin areas | $230 – $390 |
| Large, two storey or commercial | Extra height and access equipment, or documented commercial fly management | from $420, quoted on inspection |
Prices include GST. See the full pricing page for what moves a job within its range.
Questions
What people ask about spiders and flies
What does a spider treatment cost in Auckland?
An exterior treatment for a standard house is $190 to $290, interior and exterior together $310 to $420, and fly treatment $230 to $390. Larger and two-storey homes, and commercial premises, start from $420 and are quoted once we have seen them. What moves a job within its range is mostly the outside of the building: the length of eave, how high it is, and how much cladding and fencing needs covering.
Is there a permanent fix for spiders?
No, and we will not tell you it can. A residual treatment cuts down the web builders on the treated surfaces for a few months, while new spiders keep arriving from gardens, hedges and reserves. The realistic aim is fewer webs on the house and fewer spiders indoors, and it is worth remembering that spiders eat a good share of the flies and moths you would otherwise have.
Why are there suddenly so many spiders around?
Usually because of the season rather than an infestation. In late summer and autumn the mature males of several species leave their retreats to find a mate: Avondale spider males come indoors from January to March and vagrant spider males in autumn. Outdoor lights make it worse by drawing in the insects that web builders feed on, so webs collect around lit windows and doors.
Is the spray safe for children and pets?
We apply products to label directions, mostly to exterior surfaces, and ask that children and animals keep away from anything treated until it has dried. Tell us about fish ponds, aquariums and beehives before we start, because residual insecticides are toxic to fish and bees, and we change where we apply and what we use around them. Living areas inside are not sprayed by default.
Do you treat white-tail spiders?
Yes, and the effective way to do it is indirect. White-tails build no web and feed on other spiders, chiefly the grey house spider, so treating the webbing species on the outside of the house is what reduces them. Inside, keep clothes and towels off the floor and shake out shoes left by the door. We have also written up what a white-tail bite actually does.
Why do I suddenly have a lot of flies in my house?
There are three usual causes. Sluggish grey flies gathering at sunny windows in autumn have wintered in the roof space or the walls: those are cluster flies. A burst of large metallic blowflies in one room usually means a dead rat or bird nearby, and if you have had rodents, start looking there. Ordinary house flies in numbers point to a breeding source outside, such as bins, compost or pet waste.
Which months are best for spider spraying?
We recommend late summer into early autumn, so the treatment is fresh before the autumn rise in wandering spiders and before cluster flies look for a place to spend the winter, and a repeat in spring where webbing is heavy. That timing is our own recommendation rather than a published rule. Whatever the month, choose a dry, still day and dry surfaces.
Will you get rid of a katipō?
No. Katipō are native, they are declining, and the Wildlife Act 1953 gives them Absolutely Protected status, so we never treat, kill or remove one, and we never spray dunes. It lives on coastal sand dunes rather than on houses. The black spider in your shed or garage is almost always the false katipō, which we deal with as part of a normal spider treatment.
What are the small flies around my fruit bowl?
Almost always vinegar flies (Drosophila), which breed in ripe fruit, bins and recycling and go once the source does; spraying is not needed. They are not the Queensland fruit fly, a biosecurity pest that we never treat. If one turns up, take a photo, trap it if that is easy, and ring MPI's pest and disease hotline, 0800 80 99 66.
Guides
Spider and fly guides: bites, katipō, spraying and cluster flies
Do white-tail spider bites really cause flesh damage?
Do white-tail spider bites cause necrosis? What the 130-bite study and the Christchurch Hospital review found, what a real bite does, and when it needs a doctor.
Read this Venomous spidersIs it a katipō? New Zealand's venomous spiders and their look-alike
How to tell New Zealand's two venomous widow spiders from the harmless false katipō, where each is found, why the katipō is protected, and what to do after a bite.
Read this Spider sprayingWhen to spray for spiders in New Zealand
The best months and weather to spray for spiders in New Zealand, which product types last on which surfaces, and the order to treat eaves, frames and fences.
Read this Cluster fliesCluster flies in the house every autumn
Why slow cluster flies gather in sunny upstairs windows each autumn in New Zealand, where they spend the winter, and what actually reduces them the next year.
Read thisRelated
Other exterior treatments
Wasp & Bee Nest Removal
Wasp nests are treated at the nest entrance, normally at dusk when the colony has returned, and a correctly treated Vespula nest is dead within about twenty-four hours.
Read about it CockroachesCockroach Control
The species decides the treatment.
Read about it AntsAnt Control
The two ant species that cause most Auckland problems, the Argentine ant and the white-footed house ant, both form very large colonies with many queens and many nests.
Read about itDealing with spiders and flies?
Describe what you have seen, or send a photograph. We will tell you what it is and what it needs before anyone visits.