The point of bringing these Salticids up was that a study has shown that the whirling technique used by the cellar spiders is effective against the attacks from the spider hunting jumping spiders (Jackson, 1990). Portia jumping spiders made the news not too long ago for their problem-solving abilities potentially being a sign of a level of intelligence that is uncommon in arthropods, but I’ll save that for another post. Many jumping spiders predate on web dwelling spiders by pouncing on them from outside the web, however Portia jumping spiders invade the web and actually use aggressive mimicry against the cellar spiders. The jumping spiders of the Genus Portia are particularly known for their ability to predate on web building spiders and have been consistently observed feeding on Pholcus phalangioides (Jackson, 1990). This is particularly necessary because whilst they hunt spider, they are also predated on by other spiders, most notably jumping spiders (Salticids), it really is a spider eat spider world out there. Further, they become a far harder target to accurately attack. By rapidly moving their body in a circular motion they can potentially appear much larger than they are to their attacker. Furthermore, they exhibit a behaviour known as ‘whirling’ where they whip their small body around in circles, which is thought to aid them in several ways when being predated on. It is not uncommon to find cellar spiders with one or two legs missing from their close encounters with their dangerous prey. Their gangly legs give them a defensive advantage as well and they will often abandon a leg that has been caught by their attacker whilst again making a hasty retreat. phalangioides is often observed throwing silk at its attacker before making a hasty retreat. For example, when confronted aggressively by larger spiders, P. However, many of these offensive behaviours are also employed when on the defensive and become particularly important when attempting to take down larger spiders. Lacking the characteristically small body as this female is gravid (carrying eggs). A female cellar spider upside down on the ceiling of a shed. They have been observed hanging from their webs leaving as few as two legs still in contact with the web and ‘throwing’ silk over a prey item that is residing away from the web. Their first move is often to throw silk at their prey, be it a spider or an insect, before biting. Its long, thin legs, do not give the spider a lot to attack and enables the cellar spider to keep its body out of reach of counter attack. As the web’s owner approaches, thinking it has caught itself some dinner, the P. To do this, the cellar spider sits next to another spider’s web and uses its legs to vibrate the web in a way that resembles the vibrations of an ensnared insect (Jackson and Brassington, 1987). phalangioides has a number of attributes and behaviours that enable it to predate on larger spiders. The size difference between these two spiders is substantial and the one you’d expect to be the hunter is the prey. There are plenty of araneophagic animals out there, but what fascinates me is the contest between these cellar spiders are your typical “house spiders”, Eratigena atrica (or Tegeneria depending on your phylogenetic stance… a topic for another day). That’s right, even arachnophobes are going to want these guys occupying their homes. Whilst they are often overlooked due to their abundance, they exhibit numerous fascinating behaviours.ĭespite their spindly appearance, these thin bodied arachnids are deadly spider hunters. Pholcids are well known for their incredibly long legs when compared to their body size and their messy, tangled webs. These spiders are spread across the world and found on every continent apart from Antarctica. They belong to the spider family Pholcidae, which is among the most speciose spider families and is comprised of approximately 1500 species (Dimitrov et al., 2013). The cellar spider ( Pholcus phalangioides), is also sometimes called a ‘daddy-longlegs’ but this is a term that I greatly dislike, due to it being used for so many different organisms (crane flies, harvestmen etc). So, I thought I would write a little post about why these common house invaders are one of my favourite species and why they should be a welcomed house guest. However, being incredibly common, does not make them boring, in fact they display several behaviours that make them particularly interesting. If you don’t believe me then go and open your airing cupboard, garage, or garden shed and I guarantee you’ll find one of these spindly spiders. I am pretty confident that these guys are probably one the most frequently encountered spiders out there, yep that’s right I am talking about the cellar spider ( Pholcus phalangioides). If, like me, you live in the UK then you will have seen this spider.
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