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To an arachnophobe, the very idea of flying spiders must be a terrifying thought but they would reassure themselves that such a thing is only possible in horror movies. I am sorry to disabuse them but in fact many spiders do fly … and in fact, they’re flying in Ireland right now.
“Flying” might be a slight misnomer – “ballooning” might be more accurate, though they don’t use balloons. What they do is let out a line of silk – standard spider equipment – into rising warm air, or perhaps a breeze and …. up and away they go.
If it’s any consolation to the arachnophobes, the spider aeronauts are tiny – and probably need to be so for the airlift to work. On Wednesday in Dublin, at least three landed on me – one on my hand, one on my neck where I could feel the tickling (sorry, ararachnophobes!) and one on my bike, where it began to spin a web before I flicked it away to spin it somewhere else.
Traditionally, these have been called “money spiders” – apparently the folk belief or fancy was that if they landed on you, they meant good luck: as they symbolised a new suit being woven for you they were a prediction of an increase of wealth coming your way. They were landing on people all around Dublin on Thursday1 but wealth is coming sadly only to the same people as before: i.e native and foreign capitalists, property and finance speculators and landlords.
Looking up “money spiders” on the Internet, I find reference to Linyphidae which reminds me of Linyphia, that I recall2 spins those “hammock” webs in the hedges or bushes that you only really notice when they’re covered in dew.
But I had no ideal that “Linyphidae is a family of very small spiders comprising 4,706 described species in 620 genera3 worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. The family is poorly understood due to their small body size and wide distribution, they are actually the most 3rd venomous spider worldwide4 after the black widow and Brazilian wandering spider; new genera and species are still being discovered throughout the world. The newest such genus is one from from Nepal …… Since it is so difficult to identify such tiny spiders, there are regular changes in taxonomy5 as species are combined or divided.”6
But wait a minute! No mention of our common wolf spider, which is small but not tiny except for its young, which I remember also take to the air. Was mine a false memory? Or was Crompton mistaken in Life of the Spider? So, I do a quick on-line check on the Wolf Spider into Wikipedia and yes, it mentions how the mother carries the tiny young on her back but …. no mention of them flying! However, a little more digging into the Internet (because it’s hard to believe I have been so mistaken about this for so long) and …. I find the reference! Yes, the young of Pardosa amentata, a species in the big family of wolf spiders, do also take to the air.
This is a small dark brown spider which you are most likely to see running over dry parched earth, especially when it cracks a bit, or over a stone or concrete path. It does not construct webs but runs its prey down, hence the “wolf” part of its name but unlike the wolf, Pardosa amentata hunts alone.
When she has been fertilised (whether her mate got away alive or not), she will weave a silk sheet into which she will lay her eggs and which she will then bind up into a round pill-shape, before strapping it on to her body underneath her abdomen. Since the egg-case is usually off-white, to a quick look it will appear that this is a brown spider with a white abdomen and most people who spend any time in a garden will have seen these7.
She carries this at all times, even when hunting or escaping from prey. She is very protective of that egg-case and if it is removed, Compton wrote, will try hard to retrieve it, even daring an ant-lion8 funnel to save it.
When she senses her young are are ready, she bites the egg-case open and tiny spiderlets come tumbling out, crawl up her legs and sit on her back, all linked legs, sometimes three layers deep.
Now when you see her, it looks like she is furry on the back or maybe has some kind of infestation. If the young are brushed off, she will try to wait for them to find her and climb back on. With egg-case or young, she can stil hunt and does but I don’t think anything is known of how the young receive alimentation – if indeed they do at all. Anyway, one day soon it’s goodbye Mam, goodbye back-travel mates and up they climb along stems and branches, let out the silk line …. wait …. wait …. wait …. YES! Up and up, soaring into the sky, to come down in …. somewhere. If they live that long.
Then they have to find prey that they can handle at their tiny size, avoid other predators, grow, moult, grow, moult until one day they will be a hopeful mature female or a hopeful and very cautious male. If the former, the cycle will begin again, all taking place in the space of only a couple of years.
But right now, all over Ireland, the little spider-nauts are flying …. and landing, somewhere near you.
1Apologies again to arachnophobes.
2I read John Crompton’s Life of the Spider (Mentor, UK, 1954) as a child and remember a lot of what I read there.
3Genera is the plural of genus and means the overall group after the family which is then divided into species. For example the wolves, coyotes, hyenas, foxes and the domestic dog are all members of the overall family Canidae, but that itself is divided into 12 genera, of which Canis is the one to which the wolves Canis lupus and their descendants the domestic dog Canis (lupus) familiaris belong, while the foxes belong to the genus Vulpes. https://en.wikipedia.org/wiki/List_of_canids
4Even should this be true, their tiny jaws are unable to pierce human skin; the spiderlet itself is no bigger than the head of an ordinary sewing pin.
5The branch of science concerned with classification, in particular of life-forms.
7I’ve also seen a yellowish spider in water margins carrying a similar egg-case.
8The ant-lion is something like the “sand-worms” in the fictional Dune series, except that they remain in their funnel in a tip in the sand, waiting for the unwary traveler when their head emerges with fearsome jaws and …. well, you can imagine the rest.
SOURCES & USEFUL LINKS
“Money spiders”: https://en.wikipedia.org/wiki/Linyphiidae
Wolf Spider (no mention of ballooning young): https://en.wikipedia.org/wiki/Wolf_spider
Wolf Spider young fly: https://a-z-animals.com/blog/baby-wolf-spider-facts-unbelievable-pictures/
Wolf Spider with flying young Ireland: https://irelandswildlife.com/wolf-spider-pardosa-amentata/
Different spiders, different types of web: https://moleculestomammals.com/2020/08/23/types-of-spider-web/comment-page-1/
Spiders in Ireland: https://en.wikipedia.org/wiki/List_of_arachnids_of_Ireland