Cellar Spiders – As Attention-grabbing as they’re Widespread

If, like me, you reside within the UK then you should have seen this spider. I’m fairly assured that these guys are in all probability probably the most ceaselessly encountered spiders on the market, yep that is proper I’m speaking concerning the cellar spider (Pholcus phalangioides). Should you do not imagine me then go and open your airing cabinet, storage, or backyard shed and I assure you will discover one in all these spindly spiders. Nevertheless, being extremely widespread, doesn’t make them boring, actually they show a number of behaviors that make them notably fascinating. So, I believed I’d write slightly put up about why these widespread home invaders are one in all my favourite species and why they need to be welcome home visitors.


The cellar spider (Pholcus phalangioides), can be generally referred to as a ‘daddy-longlegs’ however it is a time period that I tremendously dislike, resulting from it getting used for thus many various organisms (crane flies, harvestmen and so forth). They belong to the spider household Pholcidae, which is among the many most speciose spider households and consists of roughly 1500 species (Dimitrov et al., 2013). These spiders are unfold internationally and are present in each continent other than Antarctica. Pholcids are well-known for his or her extremely lengthy legs when in comparison with their physique dimension and their messy, tangled webs. Whereas they’re typically missed resulting from their abundance, they exhibit quite a few fascinating behaviors.

Spider searching

Regardless of their spindly look, these skinny bodied arachnids are lethal spider hunters. That is proper, even arachnophobes are going to need these guys to occupy their properties. There are many araneophagic animals on the market, however what fascinates me is the competition between these cellar spiders are your typical “home spiders”, Eratigena atrica (or Tegeneria relying in your phylogenetic stance… a subject for an additional day). The scale distinction between these two spiders is substantial and the one you’d count on to be the hunter is the prey. P. phalangioides has a lot of attributes and behaviors that allow it to predate on bigger spiders. First, it acts as an aggressive mimic. To do that, the cellar spider sits subsequent to a different spider’s internet and makes use of its legs to vibrate the online in a approach that resembles the vibrations of an ensnared insect (Jackson and Brassington, 1987). As the online’s proprietor approaches, pondering it has caught itself some dinner, the P. phalangioides assaults. Its lengthy, skinny legs don’t give the spider quite a lot of assault and permits the cellar spider to maintain its physique out of attain of counter assaults. Their first transfer is commonly to throw silk at their prey, be it a spider or an insect, earlier than biting. They’ve been noticed hanging from their webs leaving as few as two legs nonetheless involved with the online and ‘throwing’ silk over a prey merchandise that’s residing away from the online.

Cellar spiders
A feminine cellar spider the wrong way up on the ceiling of a shed. Missing the characteristically small physique as this feminine is gravid (carrying eggs).

Predator protection

Nevertheless, many of those offensive behaviors are additionally employed when on the defensive and turn out to be notably vital when making an attempt to take down bigger spiders. For instance, when confronted aggressively by bigger spiders, P. phalangioides it’s typically noticed throwing silk at its attackers earlier than making a hasty retreat. Their gangly legs give them a defensive benefit as properly and they’re going to typically abandon a leg that has been caught by their attacker while once more making a hasty retreat. It isn’t unusual to search out cellar spiders with one or two legs lacking from their shut encounters with their harmful prey. Moreover, they exhibit a habits often known as ‘whirling’ the place they whip their small physique round in circles, which is believed to assist them in a number of methods when being predated on. By quickly transferring their physique in a round movement they will doubtlessly seem a lot bigger than they’re to their attacker. Additional, they turn out to be a far more durable goal to precisely assault. That is notably mandatory as a result of while they hunt spiders, they’re additionally predated by different spiders, most notably leaping spiders (Salticids), it truly is a spider consuming spider world on the market. The leaping spiders of the Genus Portia are notably identified for his or her potential to predate on internet constructing spiders and have been constantly noticed on feeding Pholcus phalangioides (Jackson, 1990). Many leaping spiders predate on internet dwelling spiders by leaping on them from exterior the online, nevertheless Portia leaping spiders invade the online and truly use aggressive mimicry towards the cellar spiders. Oh, how the desk has turned. Portia leaping spiders made the information not too way back for his or her problem-solving talents doubtlessly being an indication of a degree of intelligence that’s unusual in arthropods, however I am going to save that for an additional put up. The purpose of bringing these Salticids up was {that a} research has proven that the whirling method utilized by the cellar spiders is efficient towards the assaults from the spider searching leaping spiders (Jackson, 1990). Nevertheless, there’s a predator-prey arms race between these two spiders due to the number of methods within the Portia arsenal has resulted in them typically with the ability to keep away from detection by the cellar spider till it’s too late for it to start out whirling (Jackson, 1990). That is what units the Portia other than the opposite spider searching Salticids.


I’ll have turn out to be barely distracted on the finish there by the behaviors of the leaping spiders, nevertheless it’s nonetheless considerably related. It’s fascinating that the widespread cellar spider which is discovered internationally and in your individual residence demonstrates such fascinating behaviors each when on the offensive and on the defensive. I discover it much more fascinating that one other species of spider predates on the cellar spider by using the identical techniques.

I hope that you’ve got loved this put up on the cellar spider, it has acted as yet one more instance of a standard species being extra fascinating than it first appeared. Thanks for studying, till subsequent time.

Do not forget you will discover ZoologyNotes on Twitter – Matthew Woodard @ZoologyNotes


Dimitrov, D., Astrin, JJ and Huber, BA Pholcid Spider Molecular Systematics Revisited, with New Insights into the Biogeography and the Evolution of the Group. Cladistics, 29132-46.

Jackson, RR and Brassington, RJ (1987). The Biology of Pholcus phalangioides (Araneae, Pholcidae): Predatory versatility, araneophagy and aggressive mimicry. London Journal of Zoology, 211227-38.

Jackson, RR (1990). Predator-prey interactions between leaping spiders (Araneae, Salticidae) and Pholcus phalangioides (Araneae, Pholcidae). London Journal of Zoology, 22553-9.

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