FASCINATED with spiders, scorpions and snakes ever since he was a child, Jonathan Leeming made a career out of his passion and is now an authority on the biting and stinging creepy-crawlies most of us fear.
Leeming addressed the U3A on the subject at their well-attended meeting at the Don Powis Hall in Settlers Park last week.
Born in the UK in 1970, Leeming and his family immigrated to South Africa in 1984, where he became fascinated with insects, arachnids and snakes from a young age.
He joked that his last “real job” was as an IT manager for Deloitte. “I didn’t like it. Weekends in nature was where my life was. I had to decide – is it going to be snakes and scorpions or sitting in an office all week?” He chose the creep-crawlies and became an entomologist.
He has worked with some of the most venomous creatures in the world in more than 10 countries and written nine books.
His latest work, his book called One World, focuses more on conservation and the role of humanity in the ecosystem.
As he states on his website, jonathanleeming.com: “We are the first generation who truly understands that the world our children grow up in will be vastly different from our own. As we live in the future of a decade ago, never before has humanity been so uncertain about the future. How we overcome the challenges of our time will make the difference between a world that we tolerate, and a world in which we prosper.”
His talk at the U3A was more generally about venomous creatures and their value.
One of the most common misperceptions is about the humble spider.
“Spider bite misdiagnosis in our country is absolutely rife. Medical professionals tell people they’ve been bitten by a spider without proof. Did you see the spider bite you?” Leeming asked.
“People think venomous creatures are a negative aspect of society we can live without. When we create a natural imbalance in the world we create problems. Should we be afraid of venomous animals and believe the You Magazine stories?”
Involving his audience in his presentation, Leeming asked what the largest venomous animal on Earth was. A few people correctly answered it was the Komodo dragon.
He listed a few other facts which many people may not know: the most venomous fish is the lion fish and sting ray, the most venomous snake is the vine snake, the most venomous scorpion is the Androctonus australis and the most venomous spider is the Brazilian wandering spider.
It was also a surprise to many to find out there is a venomous mammal, the solendon.
The most venomous creature of all is the box jellyfish, which can be as small as a finger.
Leeming explained how the experts measure toxicity, by injecting venom into mice and observing how many of the mice die, and then changing the amount of venom injected. The less needed to cause death reveals a high toxicity.
But he said the number of human deaths caused by a venomous creature is not a reliable indicator, as a highly venomous creature may live in a remote area where not many people are around and there are few deaths, but a less venomous creature may cause more deaths in a densely populated area. The availability of anti-venom in populated areas also reduces the number of deaths.
He explained the three general types of venom: neurotoxic venom (black mamba, Cape cobra) acts on the nervous system and brain; cytotoxic venom (puff adder) has a localised action at the site of the bite, destroying cell membranes; and hemotoxic venom (boomslang, vine snake) acts on the heart and cardiovascular system.
Scientific research has discovered amazing medical applications for some of these venoms, like rattlesnake venom for heart attacks, the gila monster’s being used to treat diabetes, the Brazilian wandering spider helping erectile dysfunction, the Chilean rose tarantula used to treat muscular dystrophy and the black mamba’s venom as a painkiller.