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

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


The cellar spider (Pholcus phalangioides), can be typically referred to as a ‘daddy-longlegs’ however it is a time period that I enormously dislike, as a consequence of it getting used for therefore 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 measurement and their messy, tangled webs. Whereas they’re typically missed as a consequence of 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 one more day). The dimensions distinction between these two spiders is substantial and the one you’d count on to be the hunter is the prey. P. phalangioides has plenty 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 manner 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 a whole lot of assault and permits the cellar spider to maintain its physique out of attain of counter assaults. Their first transfer is usually 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 other way up on the ceiling of a shed. Missing the characteristically small physique as this feminine is gravid (carrying eggs).

Predator protection

Nonetheless, many of those offensive behaviors are additionally employed when on the defensive and turn out to be significantly necessary when trying 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 effectively and they’re going to typically abandon a leg that has been caught by their attacker while once more making a hasty retreat. It’s not 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 referred to as ‘whirling’ the place they whip their small physique round in circles, which is assumed 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 significantly obligatory 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 significantly recognized for his or her skill to predate on internet constructing spiders and have been persistently noticed on feeding Pholcus phalangioides (Jackson, 1990). Many leaping spiders predate on internet dwelling spiders by leaping on them from outdoors the online, nevertheless Portia leaping spiders invade the online and really use aggressive mimicry in opposition to 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 skills doubtlessly being an indication of a stage of intelligence that’s unusual in arthropods, however I will save that for one more put up. The purpose of bringing these Salticids up was {that a} research has proven that the whirling approach utilized by the cellar spiders is efficient in opposition to the assaults from the spider searching leaping spiders (Jackson, 1990). Nonetheless, 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 begin whirling (Jackson, 1990). That is what units the Portia other than the opposite spider searching Salticids.


I could 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 ways.

I hope that you’ve 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.

Remember 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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