Black House Spiders - All you Need to Know!
|
|
The black house spider, Badumna insignis, is one of the more common spiders found around New Zealand homes. Although their bite is quite painful the main concern for homeowners is that they build unsightly, dense webs around windows, doors and eaves. Fortunately, this makes it very easy for the homeowner to carry out their own pest control treatment.
Black house spider bite
Black house spider bite symptoms
Black house spiders are actually quite timid and will often retreat into their web when disturbed. However, their bite can be quite painful and cause local swelling around the bite area. Nausea, vomiting and sweating has been recorded in a few cases. Following a black house spider bite you should follow the standard spider bite first aid.
Standard spider bite first aid:
- The patient should sit down and try to relax
- Clean the bite with water and disinfectant
- Apply an ice pack to the bite area
- If possible, collect the spider or take a picture for identification (if medical treatment is required)
- If symptoms worsen seek medical attention
Medical Disclaimer: While we make every effort to make sure the information in this website is accurate and informative, the information does not take the place of professional or medical advice.
Black House Spider Identification
What do black house spiders look like?
Black house spiders are a charcoal / black colour, although the abdomen appears grey (sometimes brownish) with white markings. Their legs can be brown and black. Females can have a body of up to 18 mm long with a leg span of 30 mm. Males are noticeably smaller and slimmer. Their dense, obvious webs are a key identifying feature, if the spider cannot be located.
Where do black house spiders live?
In their natural environment, black house spiders build their webs on tree trunks, logs and under rocks – any place where there is a crevice to hide. Around buildings, they build their webs around window and door frames, in vents and under eaves.
Black house spiders build dense webs, often with a funnel-like shape which leads to their hiding place. Their webs are not actually sticky but make up of a dense network of silk, which is designed to snag the spiny legs of insects.
Female spiders will never leave their web unless they are forced to, and will keep on adding layers of silk, making the web denser over time.
Black house spider webs
In their natural environment, black house spiders build their webs on tree trunks, logs and under rocks – any place where there is a crevice to hide. Around buildings, they build their webs around window and door frames, in vents and under eaves.
Black House Spider Lifecycle
How long do black house spiders live?
Spiderlings moult as they grow. They mature during the warmer months (having grown on plentiful prey) and live for about 2 years.
What does a black house spider eat?
Black house spiders feed predominately on insects (both crawling and flying), which get caught in their dense, stick webs. They will often build their webs on houses near sources of artificial light, which attracts flying insects.
Other interesting facts…
Males leave their webs to find females and will pluck strands on the female’s web to make sure she is receptive to mating. The males will often remain with the female for several days and mate several times – they are not consumed after mating as is often the case with redback spiders!
Black house spiders are one of the favourite prey items of white-tailed spiders. So, carrying out a treatment for black house spiders will make your property less attractive to white-tailed spiders due to the lack of food.
Black House Spider New Zealand – FAQ
Are black house spiders poisonous / venomous?
People ask whether black house spiders are poisonous, but what they really mean is, are they venomous? (Poison = something injested, inhaled or absorbed through skin, venom = something injected).
Black house spider bites are moderately venomous, although there is no need for an anti-venom. The standard spider bite treatment is generally all that’s required, although seek medical attention if concerns or unsure about spider identification.
Are black house spiders dangerous?
Although black house spiders are moderately venomous, they are not considered particularly dangerous, as bites are not that common because they are quite a timid spider. When disturbed they typically retreat quickly into their hiding place. They will generally only bite if picked up (intentionally or by accident).
What are the black house spider bite symptoms?
Black house spider bites are moderately venomous, in that the can cause pain with swelling around the bite. Sometimes they can cause sweating, nausea and dizziness.
How to get rid of Black House Spiders?
A general insecticide spray around the perimeter of the home, particularly around windows and doors, under eaves and in vents, will prevent black house spiders building their webs for many months.
If you already have black house spiders living around the outside of your home, make sure you spray the webs and into their hiding places. Leave the webs in place for at least 24 hours before brushing down the webs. Don’t wash the webs down with a hose, as it will also wash the insecticide away.
To get rid of black house spiders in the house, best to spray it directly and coat the web with PestXpert Pro-Spray Spider Blast. Once the spider has died, simply brusg the web away.
PestXpert Pro-Spray Outdoor Perimeter is the idea product for whole of house treatment, although PestXpert Pro-Spray Spider Blast is a great option for spot treatment.
More information on spider pest control…
Author:
Gordon Reidy has over 30 years experience in Pest Control Product Development and Product Safety. As the lead formulator at PestXpert, he has helped develop some of Australia’s most trusted household pest solutions. With a PhD in Toxicology, Gordon is passionate about delivering effective, science-backed products that are safe for families and the environment.
Share This Post
Further Reading
-
White Tail Spiders – All You Need to Know...White tail spiders (Lampona spp.), sometimes call white tip spiders, are found across the North Island of New Zealand, with significant populations also in Christchurch and Nelson. The two species found in New Zealand are two species are Lampona cylindrata…
-
Redback Spiders - All you need to know…The Australia redback spider (Latrodectus hasselti) has two main populations in New Zealand – in Central Otago and New Plymouth, although it is probably present elsewhere. Along with the Katipo, the redback is considered the most dangerous spider in New…
-
Huntsman spiders – Everything you need to knowHuntsman spiders are probably the largest and scariest!) spiders in New Zealand. They have been introduced from Australia and their main populations are in Auckland (the Avondale spider) and Christchurch. Their size, fast movement and ability to “jump”, coupled with…
-
The Ultimate Guide to Spider ControlSpiders do a lot of good in environment, but they are also scary to many people and some can give a nasty bite. Here are a range of prevention tips and control methods for the common spiders found in Australia.