Are there any sources that would tell us whether (any) ancient Greeks or Romans were afraid of spiders?
In this article the author is referring to a study conducted by Columbia University in New York where the leader of the study, Joshua New stated, that fear of spiders dates back to the early human evolution in Africa. It acted as sort of a survival instinct. Detecting the spider before it could bite was important for survival. And according to the study the fear of spiders evolved out of that survival instinct.
So yes, it seems quite likely that the fear was present at Greek and Roman times.
No. We might infer from the documented existence of specific phobias that one for arachnids would be possible as well. So that's really a circumstantial, weak, tiny little maybe yes.
But for arguing with evolutionary psychology?
We have to differentiate already our modern definitions for fear, anxiety and phobia. They have different wiki pages, because they are quite different. Unfortunately, phobia (φόβος), the original Greek word will cloud our investigation into ancient texts, as this distinction in definitions is wholly modern. We see a broad spectrum of emotional reactions, from 'rational' to irrational, concrete and abstract.
Further. As simple as this specific phobia seems to be and its presence to be asserted in antiquity of high face value, we cannot and mustn't jump that fast.
There is not much evidence for fear of spiders, let alone a specific phobia for spiders in ancient sources. As a phobia is very distinct from a simple fear or anxiety:
Arachnophobia is an excessive fear of spiders that results in the affected person actively avoiding direct contact with spiders, or even any mention or depiction (e.g. photos or pictures) of them. The process of avoiding spiders usually has a significant impact on their daily life by either restricting where they can go, what they can do, or resulting in significant emotional distress.
The ancient source for a specific phobia is:
Nicanor's affection (πάθoς), when he went to a drinking party, was fear (Φόβoς) of the flute girl. Whenever he heard the voice of the flute begin to play at a symposium, masses of terrors rose up. He said that he could hardly bear it when it was night, but if he heard it in the daytime he was not affected. Such symptoms persisted over a long period of time.”
Hippocrates. Vol VII. Epidemics 2, 4-7. Trans: Smith WD. Loeb Classical Library. Cambridge, MA: Harvard University Press; 1994. (online)
In this text, a typical case of phobia is labeled as a medical disorder. As you can get a specific phobia to just about anything (slugs, beards, rabbits), arachnophobia gains likelihood.
animals, fear of The fear of animals in general is known as zoophobia. Many individuals fear animals in general, as well as fearing wild animals (agrizoophobia) or particular animals such as SNAKES (ophidiophobia), CATS (ailurophobia), DOGS (cyno- phobia), INSECTS (acarophobia), MICE (musophobia), or SPIDERS (arachnophobia). Animal phobias are often acquired by children through vicarious modeling; for example, by seeing an animal in the context of a frightening situation, such as a dog attacking a person in a movie or on the street; by having a traumatic experience, such as being bitten, or by generalization (for example, an existing fear of dogs that is generalized to a fear of cats).
Animal phobias usually develop early in life, around age four, and rarely occur after age seven or eight. However, if an individual experiences a traumatic event that is related to animals later in life, such as being attacked by a dog, a lasting fear may develop even during adulthood. Most animal phobics are female.
Ronald M. Doctor et al. (Eds): "The Encyclopedia of Phobias, Fears, and Anxieties", Facts on File: New York, 32008.
Arachnophobia has historical and cultural causes. According to Graham C. L. Davey of the City University, London, “In most of Europe during the Middle Ages, spiders were considered a source of contamination that absorbed poisons in their environment (e.g. from plants). Any food which had come into contact with a spider was considered infected. Similarly, if a spider fell into water, that water was then held to be poisoned.” (Renner, 1990) Pests.org: Arachnophobia Updated for 2019
So, a collection of articles that dance around the main point here: these phobias and even fears are mainly culturally imprinted, not some evolutionary remnants, as the evidence for the latter is extremely weak and unsatisfactory. Frankly, in this as in quite some other cases they don't make much sense at all.
If there were any truth to the evolutionary origin theory,
Fear of spiders holds a lengthy history, since about the time of Jesus' birth where areas of Abyssinia were deserted through the full populace because a effect of a 'plague of spiders'. Amongst primeval peoples fear of spiders, countless African people show signs of a universal fear of sizable spiders most Amazonian Indians don't.
Cultural depictions of spiders in Greek and Roman antiquity are not really that threatening.
Stephen T. Asma: "Epistemic Territory and Embodied Imagination", Evolutionary Studies in Imaginative Culture Vol. 1, No. 1 (Spring 2017), pp. 33-36 (jstor, DOI)
Small sample disease again, plus WEIRD people again: July 2003 John M. Hettema et al.: "A Twin Study of the Genetics of Fear Conditioning", Arch Gen Psychiatry. 2003;60(7):702-708. doi:10.1001/archpsyc.60.7.702
Peter Muris: "Common childhood fears and their origins", Behaviour Research and Therapy, Volume 35, Issue 10, October 1997, Pages 929-937 (DOI)
Chris Buddle: "WHY ARE WE SO AFRAID OF SPIDERS? Children say they fear spiders most, but is this down to a bad encounter? Scientists have shown arachnophobia is inheritable - you don't need to necessarily experience spiders to be fearful of them.", Independent, Wednesday 20 May 2015 14:22
Randolph R. Cornelius and James R. Averill: "Sex Differences in Fear of Spiders", Journal of Personality and Social Psychology, 1983, Vol. 45, No. 2, 377-383.
Klaas J. Wardenaar et al.: "The cross-national epidemiology of specific phobia in the World Mental Health Surveys", Psychol Med. 2017 Jul; 47(10): 1744–1760. Published online 2017 Feb 22. DOI
Mats Fredrikson et al. "Gender and age differences in the prevalence of specific fears and phobias", Behaviour Research and Therapy 34(1):33-9 · February 1996. DOI The most often cited paper for "researchers found out" evolutionary basis for arachnophobia is:
Arne Ohman et al.: "Emotion Drives Attention: Detecting the Snake in the Grass", Journal of Experimental Psychology: General, 2001, Vol. 130, No. 3, 466-478. DOI: 10.1037/AXJ96-3418.104.22.1686
But this is, well, laughable:
Participants. Twenty-five psychology students, 12 men and 13 women, volunteered on an informed consent basis to perform as research participants to gain course credits. They were not screened for fear of snakes or spiders. Their age ranged from 21 to 41 years with a mean of 28 years.
Follow these links and find weak science that is reported and cited in other papers without any proportion to the actual epistemological reach they could offer. The criteria for objectivity, reliability and validity have to be evaluated in each case when looking at sample size, sample bias, etc.
It's a bleak picture.
In doing history, culture much more often trumps biology than is commonly thought nowadays.
A much, much more convincing theory is found in
Graham Davey: "The 'disgusting' spider: The Role of Disease and Illness in the Perpetuation of Fear of Spiders", Society & Animals, Volume , Issue 1, 1994 (DOI):
The development of the association between spiders and illness appears to be linked to the many devastating and inexplicable epidemics that struck Europe from the Middle Ages onwards, when the spider was a suitable displaced target for the anxieties caused by these epidemics. Such factors suggest that the pervasive fear of spiders that is commonly found in many Western societies may have cultural rather than biological origins, and may be restricted to Europeans and their descendants.
If you continued to read this far, enjoy a video or two, that laugh in the face of evolutionay theories for this: Primitive Technology - Find big Black Spider by bamboo - Eating Spider delicious, Primitive People - Australian Aborigines (1950s), Hairy Delicacy - Cambodian Tarantula.