Sunday, March 19, 2017

Voracious Predators













Come dine with me! Image credit: bemiedup, CC BY-NC-SA

Of course, we know spiders. These are air-breathing arthropods that have eight legs, chelicerae with fangs that are generally able to inject venom, and spinnerets that extrude silk. 

Oftentimes, we overlook these arachnids. Did you know that because they are so abundant, they are the most important predators of insects? 

Spiders have been used to control insects in apple orchards in Israel and rice fields in China. Large numbers of spiders have also been observed feeding on insects in South American rice fields and in fields of North American crops. Modern pest-management strategies emphasize the use of insecticides that do the least damage to natural predators of insect pests.

Spiders (Class: Arachnida; Order Araneae) – of which there are more than 45,000 species with a collective weight of about 25 million tons – devour up to 800 million tons of prey each year, making them some of the world’s most voracious predators, according to calculations by a team of Swiss and Swedish scientists.

Most of their victims are insects but the largest tropical species occasionally make a meal of vertebrates such as frogs, lizards, fish and even small mammals.

Martin Nyffeler, from the University of Basel in Switzerland says. “In concert with other insectivorous animals such as ants and birds, they help to reduce the population densities of insects significantly”.

Nyffeler continues: “Spiders thus make an essential contribution to maintaining the ecological balance of nature”.

And adds Nyffeler: “We hope that these estimates and their significant magnitude raise public awareness and increase the level of appreciation for the important global role of spiders in terrestrial food webs”.

The appetite of spiders even exceeds that of whales, which get through an estimated 280 million to 500 million tons of prey a year.

In comparison, all the humans on Earth consume about 400 million tons of meat and fish each year, according to the United Nations Food and Agriculture Organization.

[Note: Journal reference: The Science of Nature, DOI: 10.1007/s00114-017-1440-1].

On Saturday, I was at the MIMKL Toastmasters meeting to evaluate a CC #2 speech before going to the HELP University campus at Persiaran Cakerawala in Subang Bestari, Seksyen U4, Shah Alam to judge at the Area J1 International Speech & Table Topics contests.

Two events in two locations in one day really speak of my Toastmastering passion! Hmmm, if one day I decide to quit Toastmasters, it would free up a humongous amount of time for me! I wonder what would I do then?

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