Science

Ant-repelling cobweb chemical could lead to new pesticides

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Golden orb web spiders, such as the red-legged golden orb-web spider (pictured), could help to develop new ant-repelling pesticides
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Golden orb web spiders, such as the red-legged golden orb-web spider (pictured), could help to develop new ant-repelling pesticides
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Ants. What a pest. Once you get them in your house it can be a real mission to get rid of them. But it seems the Golden orb web spider has developed a way to keep its home clear of the little buggers. The secret uncovered by researchers from the National University of Singapore (NUS) and the University of Melbourne relates to a chemical compound the spider adds to its web that appears to repel ants. So not only are spider webs providing inspiration for better adhesives and stronger materials, they may also provide the basis for new, environmentally friendly, ant-repelling pesticides.

Golden orb web spiders are already in high demand amongst researchers due to the strength of their webs. The silk of this particular spider is almost as strong as Kevlar, and only a fraction of the weight. But NUS Associate Professor Daiqin Li was more interested in the possible ant-repelling nature of the spider's web after noting that, although ants were ever abundant near the webs of the orb web spiders, they don't typically end up trapped in the webs.

After observing spun webs and analyzing the compounds in the silk, the scientists soon discovered the mystery substance, which was later determined to be an alkaloid compound. Once discovered, scientists observed ants in the presence of the compound and discovered that they displayed evasive behavior whenever they came near the alkaloid.

"We found that large Golden orb web spiders add a defensive alkaloid chemical onto the silk, which stops the ants from walking onto the web when they come into contact with it," said Diaqin Li of Biological Sciences, NUS.

"The type of chemical deterrent found in the spider silk is known as a pyrrolidine alkaloid, which acts as a predator deterrent in many species of ants, moths and caterpillars," added Professor Mark Elgar from the University of Melbourne's Department of Zoology. "The orb spider is potentially vulnerable to attack from groups of ants while sitting in its web waiting for prey, so the chemical defense in web silk may have evolved to not only protect the spider, but to reduce the time and energy that would otherwise be required to chase away invading ants."

The discovery offers the prospect of the development of a pesticide for keeping ants away from where they aren't wanted.

The NUS and University of Melbourne team's paper appears in the journal Proceedings of the Royal Society B.

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8 comments
covenantfarm
Oh wait, I might get attacked by ants, so I\'ll just whip up a batch of pyrrolidine alkaloid, which based upon my research will surely repel them. Note to self: find chemicals necessary to concoct the alk, figure out where in my system to brew it, inject or otherwise get it mixed into my amazing spider silk machine. Oops, no time, here come the ants.
kuryus
covenantfarm, now, now, don\'t go pointing out the obvious. You might upset someone.
Douglas Jack
This research is a great step forward in effective pest control for a whole range of species. Observe, learn from and mimic nature\'s low cost solutions. Presently diatomaceous earth is one effective non-toxic solution for ants, but this pyrrolidine alkaloid will add to effective control for certain situations. We should always understand ants and other species as ecological and elemental by asking where are their sources of foods, where are their sources of water, where are they nesting and other such questions which help us determine lasting solutions. At the base of this article is a great response to a faulty industrial assumption of \'ciding\' = \'killing\' any problem rather than determining the weakest link in the ant ecology upon which we can be entirely effective, without even having to kill. The faulty \'kill\' analysis has led to incredibly toxic nerve poisons which are used in most commercial pesticides and ant - icides critically damaging the lives of millions of humans worldwide. www.indigenecommunity.info
Gadgeteer
Why the pointless snark, covenantfarm? The article describes the compound as the possible basis of an ant repellent, not to protect against ant attack. Believe it or not, most people aren\'t thrilled with having ants in their homes.
Harriet Russell
I don\'t like, or understand, the \"-cide\" part either. The article talks about the substance repelling ants, then goes on to say it \"offers the prospect of the development of a pesticide for keeping ants away from where they aren\'t wanted.\"
I sprinkle red pepper where I don\'t want the big ones, and let the little ones micro-clean my counter-top!
covenantfarm
Gadgeteer... pointless? No, you just missed the point. But, to your point. I also dislike ants in my house. The author who said, \"The orb spider is potentially vulnerable to attack from groups of ants while sitting in its web waiting for prey, so the chemical defense in web silk may have evolved to not only protect the spider\", is evidently disagreeing with your understanding of his thesis, where you said it was strictly a repellent,\"not to protect against ant attack\".
Gadgeteer
covenantfarm, you make no sense whatsoever. Just because it may help protect the spider from ant attacks, you argue that its only benefit for humans would likewise be to prevent attacks from ants. Yours is the worst kind of non sequitur.
covenantfarm
Gadgeteer,
Ok, everyone missed the point but Kuryus. I was speaking from the point of view of the spider not me. Read it from that perspective and you\'ll see where I was going. Maybe you won\'t agree, but that OK.