The agony of the woman in the documentary film was palpable. She said the pain was unbearable and necrosis was eating her finger. Her finger had been amputated joint by joint as the rot spread.

Other case histories followed; the culprit in every case was the same species of spider: the brown recluse of America. Modern medicine seemed to be helpless against this tiny two-centimetre-long creature.

I asked David Warrell, an authority on treating venomous animal bites, about blaming the brown recluse for these horrors. He dismissed my concerns, saying I ought not to trust my fellow filmmakers. I persisted, “But what else could cause such horrific symptoms?”

“It could be almost anything. These are unverified cases, and I wouldn’t consider them spider bites without evidence.”

I grumbled to myself, “Does he have to see the spider biting the person before he will call it a spider bite?”

In a medical review, entomologist Richard Vetter and toxinologist Geoffrey Isbister note several medical conditions mimic spider bite symptoms, including bacterial and viral infections, diseases, allergies, and flea and bed bug bites. In an American national study, about 30 per cent of patients with skin lesions claimed to have been bitten by spiders, when they actually suffered from an infection caused by methicillin-resistant Staphylococcus aureus (MRSA).

Spiders take the rap from both the uninformed and doctors. Florida’s poison control centres received 844 reports of brown recluse bites over a six-year-period, 15 per cent from medical personnel. But only 70 recluse spiders have been found in Florida in 100 years. No wonder David was particular about evidence.

To confirm a case of spider bite, clinicians need all of these three criteria to be fulfilled: records of the clinical effects of the bite, the spider caught at the time of bite, and its identity determined by an expert.

Fifteen years ago, Phillip Anderson, a Missouri physician and recluse expert, said although several deaths caused by recluses have been reported, not one has been proven. That remains true today.

In reality, spiders are better behaved than we give them credit. In six months, one family in Kansas collected 2,055 recluse spiders from their home. In an Oklahoma barn, spider hunters caught 1,150 over three nights. Despite these high numbers, no human resident was bitten. They are, after all, called recluses for a reason.

What about India? Is any species dangerous to human life? In early May last year, villagers in Sadiya, near the Assam-Arunachal Pradesh border, claimed swarms of spiders were attacking them. A man and a boy were purportedly killed in Tinsukia district. Some newspapers wildly claimed the creatures were black widow spiders. How did these natives of North America find their way to remote Assam?

Tarantula expert Manju Siliwal at Wildlife Information Liaison Development Society, Coimbatore, visited the area during the panic. No one witnessed a spider biting anyone. No autopsy of the two purported victims was done. The rumour began with a television reporter. She identified a specimen a villager had caught as Chilobrachys assamensis, a tarantula until then known from Sivasagar, almost 200 km away.

I did find a spider bite victim closer to home: Mittal Gala who works at the Croc Bank. She said the bite of a captive Indian ornamental tarantula from the Western Ghats caused extreme pain for about six hours and muscle cramps for a week. She couldn’t hold a pen for more than five minutes or walk more than 50 steps. But the symptoms passed without permanent effects. That’s the most serious case of a confirmed spider bite we’ve heard in India.

David and colleagues from Oxford, U.K., reported that hobbyists bitten by pet Indian ornamental tarantulas also suffered from local swelling, rash, and shivering, besides severe pain and muscle cramps.

Spiders are reticent. Unfortunately, we are too quick to believe rumours of how terrible they are. There’s no doubt a few spiders cause immense human misery worldwide, but should we indict the entire lot of them?

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