Feature

Great Suffocating Spiders!

Dr Simon D Pollard

In Canterbury Museum's "Victorian Museum", directly opposite the mummy's head, in a glass cabinet, is an artefact from the New Hebrides (Vanuatu) that resembles a flaccid, wool-coloured, dunce's hat. The label, written in the early 1900s, describes it as a "spider-web cap" that was used for "smothering adulterous women".

In what seems to be a macabre literation of the saying "if the cap fits, wear it", the silken cap, by being pulled over a woman's head and fastened beneath her chin, caused the unfortunate victim to suffocate.

This silken equivalent of a plastic bag was made by passing a cone-shaped piece of wood backwards and forwards through numerous spider webs until it was covered with a thick felted mass of spider silk. The wooden cone was withdrawn so the conical cap could accommodate a human head.

The Shroud of Nephila

The unwitting partner in this bizarre punishment is the golden-silk or giant wood spider Nephila. Keith McKeown, author of Spider Wonders of Australia published in 1936 writes:

The female spider -- the sex usually seen in the webs -- is a huge and striking creature of repulsive appearance. Even when one is accustomed to association with spiders at close quarters, it is almost impossible to repress a backward start of revulsion when, as one pushes through the bush, this huge spider is suddenly seen hanging in its web a few inches away from one's face.

However, McKeown concedes: "Having conquered our aversion sufficiently to examine the spider closely, we are forced to admit that it is a handsome, even a beautiful creature". Nephila are enormous spiders and common throughout the tropics. The female can have a body seven centimeters long and a leg span up to 20 centimeters. Compared to the female, the male is a tiny dwarf, but more about him later.

Nephila build webs similar in appearance to the familiar orb-webs seen around houses, but they can be up to two meters in diameter and are very strong. These webs have attracted the attention of naturalists, including Charles Darwin, for many hundreds of years, presumably because many of them accidentally walked through them. Sir Hans Sloane, in his modestly titled book of 1725 (A Voyage to the Island, Madera, Barbados, Nieves, S. Christopher and Jamaica, with the Natural History of the Herbs and Trees, Four-Footed Beasts, Fishes, Birds, Insects, Reptiles etc. of the Last of those Islands) wrote of a large spider which makes webs "so strong to give a man inveigled in them trouble for sometime with their viscid, sticking quality. They will stop not only small birds, but also wild pigeons".

One hundred and twenty years later, in The Voyage of the Beagle, Charles Darwin described, how in Brazil "every path in the forest is barricaded with the strong yellow web of a species belonging to some division within the Epeira clavipes of Fabricius (= Nephila), which was formerly said by Sloane to make, in the West Indies, webs so strong as to catch birds".

Although, small birds and bats do get caught in Nephila webs, and probably are eaten at times by the female, flying insects are more common prey.

In a collection of wonderfully titled books -- LM'd Albertis (1880) New Guinea: What I Did and What I Saw (Vols. 1 & 2), J Gaggin (1900) Among the Maneaters, EA Pratt (1906) Two Years among New Guinea Cannibals and AS Meek (1913), A Naturalist in Cannibal Land -- various natural historians, who obviously did not pass through the digestive system of their subjects, but did pass through the webs of Nephila, all wrote about their size and strength.

Returning to McKeown, who having recovered from seeing a female Nephila in her web, went on to write:

When traveling through the bush, it is not unusual to encounter the webs of these spiders suspended between two trees; the first intimation of their presence is, usually, the drag of the strong viscid threads drawn across the face. The strength of the silken strands of the snare of Nephila is astonishing; it is not unusual for a man's hat to be snatched from his head by the sudden contact of one of these webs.

I accidentally walked through a Nephila web, while hatless, in Sri Lanka. The silk stretched across me and the skin on my face was pulled back towards my ears, as if an invisible cosmetic surgeon was selling me a face-lift. As I took another step, the silk strings pinged and my face popped forward.

While most female spiders are larger than males of the same species, female Nephila are about 400 times heavier than the male. McKeown eloquently noted this size disparity: "The male is a puny and insignificant pygmy in comparison with its great mate". While we may shudder at the thought of such a scenario in humans, I'm sure many women would savour the idea of, at least being courted by, men the size of mice.

Because females are so huge and have cannibalistic tendencies, mating is a risky pastime for male Nephila. McKeown writes of the dangers:

He approaches his bride-to-be with every evidence of caution; he seems to be fully aware that he is indeed embarked upon a great and dangerous adventure. He tests every thread carefully before trusting his weight to it, but woe betide him if, in his anxiety, he vibrates the web ever so slightly, for in that instance he meets with an untimely end -- and provides his prospective bride with a meal be it ever so small; perhaps he is too minute to be termed a meal, but at least he is an appetizer!

While some males manage to escape intact after mating, others lose limbs, and still others end up with their sperm where it should be, but the rest of their body inside the female's stomach!

Even less fortunate males are cannibalised as virgins. I have seen tiny male amputees with only three legs limping tragically across the web towards the female, presumably hoping she will still respect him as a worthy, but largely legless, suitor. To add insult to real injury, females may mate with many males, before laying eggs.

Males captured by female Nephila are wrapped in a shroud of silk. Ironically, this is the same silk that was used to smother adulterous women in the New Hebrides. The silk in both cases comes from a female that is not only cannibalistic, but also an adulterer.

I'm sure if New Hebridean males were the size of mice, Nephila webs woven into a cap would never have ended up on the heads of New Hebridean women.

Dr Simon D Pollard is Curator of Invertebrate Zoology at Canterbury Museum.