Cellar Spiders – As Fascinating as they’re Widespread

Cellar Spiders – As Fascinating 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 most likely one essentially the most often encountered spiders on the market, yep that is proper I’m speaking in regards to the cellar spider (Pholcus phalangioides). If you happen to do not imagine me then go and open your airing cabinet, storage, or backyard shed and I assure you may discover considered one of these spindly spiders. Nonetheless, being extremely widespread, doesn’t make them boring, actually they show a number of behaviors that make them notably attention-grabbing. So, I assumed I might write a bit of put up about why these widespread home invaders are considered one of my favourite species and why they need to be a welcomed home visitor.


The cellar spider (Pholcus phalangioides), can also be typically known as a ‘daddy-longlegs’ however this can be a time period that I vastly dislike, as a result of it getting used for thus many various organisms (crane flies, harvestmen and many others). They belong to the spider household Pholcidae, which is among the many most speciose spider households and is comprised of roughly 1500 species (Dimitrov et al., 2013). These spiders are unfold internationally and located on 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. While they’re usually neglected as a result of their abundance, they exhibit quite a few fascinating behaviours.

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 occupying 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 dimensions distinction between these two spiders is substantial and the one you’d anticipate to be the hunter is the prey. P. phalangioides has quite 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 net and makes use of its legs to vibrate the net in a means that resembles the vibrations of an ensnared insect (Jackson and Brassington, 1987). As the net’s proprietor approaches, considering it has caught itself some dinner, the P. phalangioides assaults. Its lengthy, skinny legs, don’t give the spider quite a bit to assault and allow the cellar spider to maintain its physique out of attain of counter assault. 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 net and ‘throwing’ silk over a prey merchandise that’s residing away from the net.

Cellar spider
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 notably necessary when making an attempt to take down bigger spiders. For instance, when confronted aggressively by bigger spiders, P. phalangioides is commonly noticed throwing silk at its attacker earlier than making a hasty retreat. Their gangly legs give them a defensive benefit as effectively and they’ll usually abandon a leg that has been caught by their attacker while once more making a hasty retreat. It’s not unusual to seek 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 believed to assist them in a number of methods when being predated on. By quickly shifting their physique in a round movement they’ll doubtlessly seem a lot bigger than they’re to their attacker. Additional, they turn out to be a far tougher goal to precisely assault. That is notably obligatory as a result of while they hunt spider, they’re additionally predated on by different spiders, most notably leaping spiders (Salticids), it truly is a spider eat spider world on the market. The leaping spiders of the Genus Portia are notably identified for his or her capability to predate on net constructing spiders and have been constantly noticed feeding on Pholcus phalangioides (Jackson, 1990). Many leaping spiders predate on net dwelling spiders by pouncing on them from exterior the net, nevertheless Portia leaping spiders invade the net 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 an additional 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 as a result of the number of strategies within the Portia arsenal has in them usually having 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, but it surely was nonetheless considerably related. It’s fascinating that the widespread cellar spider which is discovered internationally and in your personal dwelling display such attention-grabbing 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 one more instance of a standard species being extra attention-grabbing than it first seems. Thanks for studying, till subsequent time.

Do not forget yow 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. Journal of Zoology London, 211227-38.

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