A ladybird's colour reveal its level of toxicity

A new study shows that for ladybirds, the brightness of their color reveals the extent of their toxicity to predators. The research also found that the more conspicuous and colorful the ladybird species, the less likely it is to be attacked by birds.

The brighter the ladybird the more toxic it is to predators, new research from the Universities of Exeter and Cambridge show.

Although red ladybirds with black spots are most familiar, ladybirds are a diverse group of species and come in many different colours and patterns, from yellow and orange to even camouflaged browns. The bright colouration of different ladybird species acts as a warning signal, telling potential predators to beware of the foul smelling, poisonous chemicals they use for defence.

The study which is published in the journal Scientific Reports, also found that the more conspicuous and colourful the ladybird species, the less likely it is to be attacked by birds.

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Ladybird colors reveal their toxicity

Date:

June 5, 2015

Source:

University of Exeter

Summary:

For one of Britain's best-loved and colorful group of insects, ladybirds, the brightness of their color reveals the extent of their toxicity to predators, according to new research. Although red ladybirds with black spots are most familiar, ladybirds are a diverse group of species and come in many different colors and patterns, from yellow and orange to even camouflaged browns.

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Black widow spider venom unveiled: The fast evolution of a potent toxin

Date:

January 6, 2015

Source:

Society for Integrative and Comparative Biology (SICB)

Summary:

New research shows rapid evolution has helped to make the venom of black widow spiders so toxic.

Dr. Jessica Garb of the University of Massachusetts, Lowell, along with a team of collaborators in the US and the UK, has been attacking these questions by studying the spider's genetics, protein expression, and venom content, searching for clues about just how the widow spider's venom evolved to be so potent.

The most potent neurotoxins present in black widow venom are called latrotoxins, which takes its name from the group of widow spiders known as Latrodectus. The most toxic of these latrotoxins is alpha-latrotoxin, a devastatingly debilitating chemical that hijacks the body's own internal communications, the electrical and chemical signaling of the nervous system.

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Cane toads continue to spread poison in WA, Australia-4/12/14 - via Herp Digest

TOXIC cane toads have reportedly wiped out entire species of animals in the world heritage-listed Purnululu National Park, home to Western Australia's famed Bungle Bungles.

Kimberley Toad Busters (KTB) founder Lee Scott-Virtue said cane toad numbers had reached staggering numbers as they invaded every habitat system.

The first toad arrived just east of the Bungle Bungles - the large cone-shaped quartz sandstone ranges formed from erosion over 20 million years - in May last year.

The poisonous creatures had already wiped out some entire species of animals in the areas they infected including quolls and some reptiles such as king brown snakes.

Ms Scott-Virtue said visitors and people working in the park were horrified by the number of toads that had appeared since the wet season.

She warned numbers would continue to increase if nothing was done about their breeding.

"It's going to happen in every national park," Ms Scott-Virtue told AAP on Monday.

One operator commented that despite busting toads every night, there seemed to be just as many the next night, Ms Scott-Virtue said.

The Department of Parks and Wildlife (DPaW) has put in live toad drop boxes in the park but Ms Scott-Virtue said those toads were usually only found in permanent camp sites at night, which made up about one per cent of the total area of the park.

Killing toads in the national park remains prohibited and DPaW have banned the use of Dettol in the park - the only effective method of killing the metamorph, Ms Scott-Virtue said.

KTB was granted permits to work in the park but found the restrictions too prohibitive because they had to take the toad catch out of the park to euthanase and were not allowed to use Dettol to deal with the immature metamorphs.

They were also restricted to specific areas that contained designated vehicular tracks, which meant there was no access to a large part of the park to undertake appropriate toad busting, she said.

KTB has been trialling the use of Dettol on metamorphs congregating around water edges since 2006.

The group says there has been little residual evidence of Dettol afterwards and no evidence of bi-catch.

Cane toads were introduced to Queensland in 1935 and began spreading to the Northern Territory before invading northern WA in 2009.

They are now advancing into the state at a rate of about 50 kilometres a year.

The KTB has not had any government funding since last June.

Venomous Hobo Spider Bites May Be Not So Toxic After All

By Agata Blaszczak-Boxe, Staff Writer | April 17, 2014 10:17am ET

Whether the bites of the hobo spider are toxic to people has been a matter of scientific debate, but a new study suggests the spider's venom may be less harmful than many people think.

With black widows and brown recluse spiders, hobo spiders are listed by the Centers for Disease Control and Prevention as one of the three venomous spiders that can be found in the United States, that can be dangerous. In some cases, hobo spider bites have caused necrosis, which is the death of cells or tissue, according to a 1996 report from the CDC.

However, researchers have questioned for years whether there is actually sufficient evidence that hobo spider venom can indeed cause necrotic skin lesions, and how dangerous to humans these spiders really are. Moreover, hobo spiders are considered innocuous in Europe, and previous research comparing the venom of American and European members of the species did not find significant differences between the two.

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Plant Poison Turns Seed-Eating Mouse Into Seed Spitter

ScienceDaily (June 14, 2012) — In Israel's Negev Desert, a plant called sweet mignonette or taily weed uses a toxic "mustard oil bomb" to make the spiny mouse spit out the plant's seeds when eating the fruit. Thus, the plant has turned a seed-eating rodent into a seed spreader that helps the plant reproduce, says a new study by Utah and Israeli scientists.

"It's fascinating that these little mice are doing analytical chemistry, assaying the fruit for toxic compounds" and learning not to bite into the seed, says Denise Dearing, a coauthor of the study and professor of biology at the University of Utah.

"It adds a new dimension to our understanding of the ongoing battle between plants and animals," she adds. "In this case, the plants have twisted the animals to do their bidding, to spread their progeny."

The study was set for online publication June 14 in the journal Current Biology.

The study illustrates the first known case within a single species of what is known as the "directed deterrence" hypothesis, namely, "the fruit is trying have itself eaten by the right consumer -- one that will spread its seeds," Dearing says. "The plant produces a fruit to deter a class of consumers that would destroy its seeds."

Continued:  http://www.sciencedaily.com/releases/2012/06/120614130932.htm

Redder Ladybirds More Deadly, Say Scientists

ScienceDaily (Feb. 6, 2012) — A ladybug's colour indicates how well-fed and how toxic it is, according to an international team of scientists.


Research led by the Universities of Exeter and Liverpool directly shows that differences between animals' warning signals reveal how poisonous individuals are to predators.

Published in the journal Functional Ecology, the research shows that redder ladybugs are more poisonous than their paler peers. The study reveals that this variation is directly linked to diet in early life, with better-fed ladybugs being more visible and more deadly.

Ecologists have long assumed that there are no individual differences between the warning signals of animals of the same species. More recently, scientists have identified variation between individuals' warning signals, but have not known if these differences were meaningful and linked to levels of toxicity.

Continued:  http://www.sciencedaily.com/releases/2012/02/120206214228.htm