Daddy-Long-Legs Spiders

Scientific Name: Pholcus phalangioides

How to identify a Daddy-long-legs Spider

Daddy-long-legs spiders are easily recognised by their extremely long, skinny legs and small body. Pholcus phalangioides has a brown patch on its pale carapace and a cream to pale brown, lightly patterned abdomen. Some related species have different colour patterns, for instance, the Marbled Cellar Spider (Holocnemus pluchei) has a strongly patterned abdomen with a dark stripe on the underside.

Where are Daddy-long-legs spiders commonly found?

Daddy-long-legs Spiders are found in most urban areas, in particular houses. They make a thin, tangled web in sheltered positions were they are unlikely to be disturbed, such as under furniture, behind doors, in the corner of the ceilings, in sheds, in garages and under decks.

Why are Daddy-long-legs spiders considered a pest?

There is a persistent belief that the Daddy-long-legs Spider has the most toxic venom of all spiders. However, there is no scientific evidence to back this up. The myth probably grew from observations that the Daddy-long-legs Spider will kill and eat a Redback Spider. However, the venom is not actually that potent, even for insects.

It had been thought that the fangs of this spider were incapable of piercing human skin. Recently, however, it was shown that the tiny fangs (about 0.25 mm) were actually capable of piercing human skin in a test done on the US television show, Mythbusters but the stinging sensation produced was very short-lived. Most reputable sources, including the University of California, Riverside, still say that this species would never be considered as harmful to humans.

However, in the unlikely event of a bite from this species, a positive identification of the spider by an expert should be made and medical attention sought if any reaction persists for more than a short time.

What is the biology and lifecycle of a Daddy-long-legs spider?

The average life span of an adult daddy-long-legs can vary from 223-774 days and in that time the female may produce from two to eight egg sacs containing a mix of fertilised and unfertilised eggs.

Management Tips for Daddy-Long-Legs Spider

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 keeping 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.