Daddy long legs are inoffensive spiders that occur in all countries of the world, with the exception of Antarctica. Harmless as they are, some people pay to exterminate them using toxic sprays. This is a waste of time for 2 reasons.
- The chemical used is toxic, but very short lived, and within a few days, spiderlings drift in on threads of silk to recolonise vacated areas.
- The sprays kill everything, including predators and beneficial insects that maintain a natural balance and may increase the incidence of nastier spiders like Redbacks.
I have been reading a fabulous book called Spiders: Learning to love them (in Narrogin library). Lynne Kelly, the author is an inspirational person who studied spiders to overcome her arachnophobia, and now loves them.
The book is a mine of information. For example, did you know that a Daddy longlegs favoured food is other spiders?
They will kill much larger spiders by keeping them at a distance and wrapping them up with silk using their long legs. For example see the wrapped Huntsman spider below. They can also approach prey spider webs and tug on them like a trapped insect before nabbing the unsuspecting inhabitant.
Have you noticed that when disturbed, a Daddy long legs vibrates madly to make it harder for any potential predator to grab it. Vibration also makes any prey more enmeshed in the web.
Daddy long legs can have compound webs that contain many spiders but they have defined territories that they don’t cross without causing a fight. The ones shown are Smeringopus species - south African immigrants.
I have a theory that leaving our Daddy longlegs reduce Redback numbers. With this in mind I decided to pit a Redback against Daddy long legs and eventually found one after half a day looking and disturbing about a thousand Daddy longlegs.
I dropped the Redback in such a web complex and returning later, found a female Daddy long legs wrapping it up. Others moved in and there was an almighty fight before they all managed to feed together out of each other’s’ sight.
So withhold the spray and be grateful for the good old Daddy long legs!
More info https://en.wikipedia.org/wiki/Pholcidae