Mixed signals from poisonous moths

Date:  June 4, 2018

Source:  University of Exeter

Poisonous moths use bright red spots to warn predators to avoid them -- but natural variation in these wing markings doesn't provide clear indications of how toxic individual moths might be -- new research shows.

University of Exeter scientists studied six-spot burnet moths, which produce cyanide-based compounds to make themselves a bad snack for predators, to see if differences in colours indicated different toxicity levels.

While smaller and paler red forewing markings were associated with more cyanide in females, size and brightness of wing colour were no guide to cyanide levels in males.

"Many animals use aposematism (warning colouration) to tell predators it would be better to find lunch elsewhere," said first author Emmanuelle Briolat, of the University of Exeter.

Continued  

Mixed signals from poisonous moths

Date:  June 4, 2018

Source:  University of Exeter

Poisonous moths use bright red spots to warn predators to avoid them -- but natural variation in these wing markings doesn't provide clear indications of how toxic individual moths might be -- new research shows.

University of Exeter scientists studied six-spot burnet moths, which produce cyanide-based compounds to make themselves a bad snack for predators, to see if differences in colours indicated different toxicity levels.

While smaller and paler red forewing markings were associated with more cyanide in females, size and brightness of wing colour were no guide to cyanide levels in males.

"Many animals use aposematism (warning colouration) to tell predators it would be better to find lunch elsewhere," said first author Emmanuelle Briolat, of the University of Exeter.

Continued

Rainforest Science: Researcher Licks Frogs to Tell if They’re Poisonous (Herp Digest)

There’s a certain school of thought among wildlife biologists that you should eat any organism you study. Frog scientists—who study toxic frogs, mind you—have a similar habit: lick any frog you study. “Sometimes I just can’t wait till I get back to the lab to do the chemistry, and I want to get an idea if there is something nasty,” said frog scientist Valerie Clark to National Geographic. With limited equipment out in the rainforest, a taste test is the quickest way to tell whether a frog is poisonous. Most of them can’t kill a human, but the poison can make your throat burn and constrict.

While frog-licking works in a pinch out in the field, discussing how skin secretions tickle your palate isn’t going to pass the rigors of peer review. Clark’s new study used electrical stimulation to extract skin secretions from frogs and analyzed them in a mass spectrometer. Among the products: sucrose and a new bile acid called tauromantellic acid.

Why does the frog have a bile acid, usually found in the gut, on its skin? Poisonous frogs get their toxins from the insects they eat, and they need some kind of sequestering system so that they don’t poison themselves. Clark hypothesizes that tauromantellic acid is involved in transporting toxins from food the frog eats onto the frog’s skin. Humans haven’t evolved that system, so no, licking a lot of frogs will not make your skin secrete poisons. Depending on your feelings about hallucination, licking toads might be more up your alley.

Go to http://blogs.discovermagazine.com/discoblog/2012/02/23/rainforest-science-researcher-licks-frogs-to-tell-if-theyre-poisonous/  For video.