Invasive Joro Spider May Colonize Entire US East Coast; Do Genetic Weapons Hold Key to Battle Against Invasive Species?

It is the stuff of an arachnopobes nightmare: large as a human palm and spreading a huge web – it is the invasive Joro spider and it appears to have colonized Georgia and seems likely to spread throughout the eastern seaboard.

The joro spider is native to Japan. It began showing up in Georgia recently but there isn’t much to worry about according to The Alabama A&M and Auburn Universities Extension. They say Joro and similar spiders have been in the U.S. for about a decade and have not displaced native species. They have venom, most spiders do, but it is not medically significant. Their jaws are also adapted to biting soft-bodied insects, making bites unlikely.

A joro spider eats soft bodied insects and thus does not have the jaws to bite people. Photo credit Pam Overmeyer

Although it is so far benign in its impact -except to prey species – it is a non-native species and is being watched with care. Invasive, species, those that disrupt eco systems, are causing havoc all over the world. Many are far bigger than spiders. We have reported on a number of cases including hippos in Colombia. The hippos were brought to Colombia by drug lord Pablo Escobar and abandoned after his death. They are multiplying and may have to be killed to prevent all sorts of environmental damage. Also, There are numerous invasive species in Australia. Many of you are probably familiar with the invasion of Florida by Burmese pythons and the major efforts underway to fight them. Florida has been struggling for years, offering bounties, trying to find recipes and even importing snake hunters from Asia. A recent news article about a bobcat eating python eggs has been taken as a sign that native species are fighting back.

brown and beige snake in the grass during daytime
There are many types pythons . Burmese pythons are invasive in Florida and wreaking havoc on native wildlife.. Photo by Pixabay on

But humans are inventive and there is a never ending effort to control ongoing invasions by any means available. Recently, major advances in the war against dangerous insects point the way toward control of other invasive species. We recently reported on a major advance in the war on ticks, In the United States alone ticks are responsible for 14 dangerous diseases. Researchers at the University of Nevada have announced that they have found a way past tick defenses to modify their genes. Meanwhile, billions of genetically modified mosquitoes are to be released in Florida and perhaps California to drive down the population of the biting insects. This is similar to the very successful efforts eliminate screw worms by releasing sterilized flies. The federal government has approved the pilot program. Disease carrying mosquitoes have arrived in the US carrying yellow fever, dengue fever and Zika virus. The release, which has met with opposition, is designed to reduce the number of mosquitoes. The mosquitoes are male, which do not bite. They are designed to mate with females who will then produce a generation of females that do not survive to maturity, thus breaking the reproductive cycle.

a close up shot of a bobcat
A Florida bobcat was recently seen eating oython eggs, a sign that native species are fightingn back. l lPhoto by Alex Burr

Genetic modification can be done on large animals as well, but is likely to be even more controversial. Australia is plagued with 6 million feral cats which are annihilating native species. So Australia is considering bioengineering methods to destroy the cats, The methods under study include similar controls imposed on insects. One idea is genetically modifying the cats so that only one gender is born. This would quickly lower the population. Other options include making the animals more susceptible to disease. One thing is likely – there is likely to be more public concern about genetic assault on larger animals than there is on ticks, fleas, mosquitoes, flies or even, potentially, spiders.

animal cute grass grey
House cats are not native to Australia. They have gone feral and are annihilating many vulnerable populations of native animals.Photo by Sol Fotografías on

Published by ursusrising

long time writer and editor living in Los Angeles

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