Study solves puzzle of snail and slug feeding preferences

December 5, 2018 by Alan Williams, University of Plymouth

Gardeners have puzzled for years as to why some seedlings are more commonly eaten by slugs and snails—and new research suggests it may be down to the smells produced by young seedlings in the early stages of their development.

A study led by the University of Plymouth analysed the feeding preferences of hundreds of snails when presented with seedlings of 14 different grassland plant species.

Their work showed that snails were more likely to attack seedlings based on their preference for, or dislike of, naturally omitted volatile scents produced by the seedlings.

Scientists say the research, published in the journal Annals of Botany, provides us with a better understanding of the important role slugs and snails play in natural ecosystems.

The research was led by Dr. Mick Hanley, Associate Professor (Reader) in Plant-Animal Interactions, and Post-Doctoral Fellow Roger Shannon at the University of Plymouth. It also involved academics from the University of Southampton and the University of Lyon, France.

Dr. Hanley, the corresponding author for the research, said: "Slugs and snails are just as damaging to seedlings in natural habitats like grasslands as they are gardens. But we have known for many years that not all grassland species suffer the same likelihood of attack. This is important because variation in where and when terrestrial molluscs are active can have significant impacts on which species survive the vulnerable seedling stage. In effect, by removing some plant species as seedlings, slugs and snails help dictate the nature of the established vegetation."

The research builds on a previous smaller study which focused specifically on oilseed rape, and suggested that harnessing naturally occurring chemicals could be used as a means to protect crop seedlings being eaten by common pests

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What do slugs hate? Home remedies put to the test

By Helen Briggs BBC News

Home remedies used by gardeners to deter slugs and snails are to be tested scientifically for the first time.

Researchers at the Royal Horticultural Society are investigating whether the likes of egg shells and copper have any effect in keeping slugs away.

The RHS is starting scientific trials of five traditional remedies to see if they are based on science or myth.

Dr Hayley Jones says the results, available in the autumn, will help them advise gardeners with real confidence.

"It will really start to tell us how well some of these barriers work," she said. "Is it worth spending your time and money on them?"

Until now there has been no formal study of the benefits of copper tape, sharp horticultural grit, pine bark mulch, wool pellets and egg shells, compared with doing nothing, she said.

Continued  

Slimy slugs inspire 'potentially lifesaving' medical glue

By James GallagherHealth and science reporter, BBC News website

28 July 2017

A defensive mucus secreted by slugs has inspired a new kind of adhesive that could transform medicine, say scientists.

The "bio-glue" is incredibly strong, moves with the body and crucially, sticks to wet surfaces.

The team at Harvard University have even used it to seal a hole in a pig's heart.

Experts have described the glue as "really cool" and said there would be "absolutely huge demand" for it.

Getting something to stick to a damp surface has been a huge challenge - think what happens when you get a plaster on your finger wet.

The university's Wyss Institute for Biologically Inspired Engineering turned to the "Dusky Arion" slug, which creates sticky mucus as a defence against predators.

"We engineered our material to take on the key features of slug mucus and the result is really positive," researcher Dr Jianyu Li said.

Continued   

Monster slugs are attacking birds in Europe

Slugs aren't usually considered predators.

BRYAN NELSON

August 29, 2016, 5:28 p.m.

An orange slug from the Arion genus. (Photo: Guillaume Brocker/Wiki Commons)

Death by slug: It's not a good way to go, but that's exactly what's happening to baby birds in Poland. Researchers there have witnessed a surprising pattern of large slugs of the Arion genus crawling into the nests of birds and eating the hatchlings alive, reports New Scientist.

A trail of slime is the only evidence remaining from such attacks. The behavior is so unusual that the birds' parents don't even try to defend them, possibly because they don't see the slugs as a threat until it's too late. One parent bird was even witnessed incubating a slug feeding on its dead chicks.

“The actual moment of slugs predating on nestlings isn’t easy to observe,” explained Katarzyna Turzańska from the University of Wroclaw in Poland, one of the researchers in the study. "You are more likely to come across the traces of the ‘tragedy’: dead or alive nestlings with heavy injuries, covered in slime – and often slugs’ droppings found nearby."

The researchers' work appeared in the Journal of Avian Biology.

Turzańska and colleague Justyna Chachulska have been researching this behavior since they observed it for the first time while studying whitethroat birds near Wroclaw, in Poland. Although predation by slugs has been recorded before across Europe, almost all of these reports pertain to bird species that nest close to the ground. That giant slugs would seek out treetop-nesting birds as food is a surprise, however. It appears unprecedented.

Slugs in the Arion genus can grow quite large, and they'll eat almost anything. While most slugs spend their time dining on leaves and rotting plants, they have been known to devour earthworms and other smaller slugs. Decomposing animals are certainly on the menu as well. And, apparently, now they've expanded their appetite to include live chicks.

Continued

'Sleepless slugs' on rise, say experts

The slug invasion that could devastate your garden

Last year's wet summer, followed by one of the warmest winters on record, has helped to create a generation of sleepless slugs, wildlife experts have warned.

The weather has not been cold enough in recent months to send the creatures into hibernation.

Conservation charity BugLife said Britons could start to a see a slug population "explosion".

This could cause "devastation for our gardens", it warned.

'Devastation for gardens'

Slugs stay active when temperatures remain above 5C (41F).

Because of the warm winter, slugs have not gone into hibernation and have been eating and and breeding through the winter months.

Slug snippets:

There are about 30 species in the UK. Most are vegetarian but a few are carnivorous

Slugs have two retractable pairs of tentacles. The upper pair are for vision and smell

The lower pair are are smaller and are used for feeling and tasting

A slug's two eye-stalks can move independently and can be re-grown if lost

Slug pests cause an estimated £8m of damage to vegetable crops each year

But slugs also eat decaying vegetation and so play an important ecosystem role

The average British garden usually has as many as 20,000 slugs - with the gastropods laying as many as 200 eggs per cubic metre - but Buglife predicted that number could increase over this year by 10%.

It said a decline in populations of many of the slugs' predators, such as amphibians and hedgehogs, was also a factor.

http://www.bbc.co.uk/news/science-environment-36166774

Worms hitch rides on slugs when traveling to far flung places

Slugs provide essential public transport for small worms in the search for food

Date: July 12, 2015

Source: BioMed Central

Summary: Slugs and other invertebrates provide essential public transport for small worms in the search for food, according to new research.

Slugs and other invertebrates provide essential public transport for small worms in the search for food, according to research published in the open access journal BMC Ecology.

Nematode worms (including Caenorhabditis elegans) are around a millimeter long and commonly found in short-lived environments, such as decomposing fruit or other rotting plant material. The worms face a high level of unpredictability in these environments as temperature and food availability fluctuate, and frequently need to move to new locations. However, little is understood on how such a small animal with limited mobility is able to travel long distances to find new food.

Continued ...

One will really amaze you, the other just eats his mates

High in the mists that shroud Mount Kaputar, near Narrabri in north-western NSW, scientists have discovered a secret world.

By day it is an isolated pocket of snow gums, wrapped in straggling native vines.

But on rainy nights, it is the domain of giant, fluorescent pink slugs - up to 20 centimetres long - and carnivorous, cannibal land snails that roam the mountaintop in search of their vegetarian victims.

''It's just one of those magical places, especially when you are up there on a cool, misty morning,'' said Michael Murphy, a national parks ranger for 20 years, whose beat covers the mountain top.

''It's a tiny island of alpine forest, hundreds of kilometres away from anything else like it. The slugs, for example, are buried in the leaf mould during the day, but sometimes at night they come out in their hundreds and feed off the mould and moss on the trees. They are amazing, unreal-looking creatures.''

Locals had long reported seeing bizarre pink slugs after rainfall in the area, but it was only very recently that taxonomists confirmed the slugs, Triboniophorus aff. graeffei, as well as several of the snail species - which prey on other vegetarian land snails - were unique to the mountaintop.

Continued

Who What Why: Are British slugs under threat?

A "super breed" of slugs has arrived from Spain, but are they a threat to the UK's native slugs?

The wet weather has resulted in myriad problems for people around the country and now there is another - it has helped a "super breed" of slug from Spain flourish in the UK.

Numbers of the creature commonly known as the Spanish stealth slug, Arion flagellu, are growing fast in the UK - helped by the wet weather - and threatening native molluscs, say experts in the field.

Another Spanish slug, Arion vulgaris, has already become a huge problem in Norway, attacking farms and gardens. Researchers fear the same could eventually happen in the UK.

Why the Spanish stealth slug poses such a problem is its aggressive breeding cycle. It produces hundreds more eggs than native slugs and so numbers multiply quickly. It also brings with it new diseases and parasites which can kill British slugs.

"It is a real concern," says Dr les Noble, a slug expert from Aberdeen University. "I have been collecting and analysing data on slugs for 30 years and it is clear to me that this incoming species is getting a foothold in the UK and spreading."

Their aggressive breeding cycle mean they lay around 400 eggs in a year, compared to the 100 or so laid by native species, says Dr Noble. Another problem is the diseases and parasites the slugs - which can grow to 10cm - carry.

"The Spanish stealth slug has evolved to deal with these diseases and parasites," says Dr Noble.

Continued:  http://www.bbc.co.uk/news/magazine-18672728

Amorous slug, orange snake among finds on Borneo

RIGHT: Dendrelaphis kopsteini

By VIJAY JOSHI, Associated Press Writer Vijay Joshi, Associated Press Writer – Thu Apr 22, 1:20 am ET

KUALA LUMPUR, Malaysia – A lungless frog, a frog that flies and a slug that shoots love darts are among 123 new species found in Borneo since 2007 in a project to conserve one of the oldest rain forests in the world.

A report by the global conservation group WWF on the discoveries also calls for protecting the threatened species and equatorial rain forest on Borneo, the South China Sea island that is the world's third-largest and is shared by Malaysia, Indonesia and Brunei.

"The challenge is to ensure that these precious landscapes are still intact for future generations," said the report released Thursday.

The search for the new species was part of the Heart of Borneo project that started in February 2007 and is backed by the WWF and the three countries that share the island.

The aim is to conserve 85,000 square miles (220,000 square kilometers) of rain forest that was described by Charles Darwin as "one great luxuriant hothouse made by nature for herself."

Explorers have been visiting Borneo for centuries, but vast tracts of its interior are yet to be biologically explored, said Adam Tomasek, leader of WWF's Heart of Borneo project.

"If this stretch of irreplaceable rain forest can be conserved for our children, the promise of more discoveries must be a tantalizing one for the next generation of researchers to contemplate," he said.

The scientists' discoveries include the world's longest known stick insect at 56.7 centimeters, a flame-colored snake and a frog that flies and changes its skin and eye color. In total, 67 plants, 29 invertebrates, 17 fish, five frogs, three snakes and two lizards and a brand new species of bird were discovered, said the report.

Borneo has long been known as a hub for monster insects, including giant cockroaches about 4 inches (10 centimeters) long.

Notable among the species discovered are:

• a snake that has a bright orange, almost flame-like, neck coloration that gradually fuses into an extraordinary iridescent and vivid blue, green and brown pattern. When threatened it flares its nape, revealing bright orange colors.

• A frog that breathes through its skin because it has no lungs, which makes it appear flat. This aerodynamic shape allows the frogs to move swiftly in fast flowing streams. Although the species was discovered in 1978, it was only now that scientists found the frog has no lungs.

• A high-altitude slug found on Mount Kinabalu that has a tail three times the length of its head. They shoot calcium carbonate "love darts" during courtship to inject a hormone into a mate. While resting, the slug wraps its long tail around its body.

The Heart of Borneo, the core island area the conservation effort targets, is home to ten species of primate, more than 350 birds, 150 reptiles and amphibians and a staggering 10,000 plants that are found nowhere else in the world, the report says.

http://news.yahoo.com/s/ap/20100422/ap_on_sc/as_malaysia_borneo_s_bounty

World's Longest Bug And 'Ninja' Slug Discovered in Borneo

RIGHT: This WWF Malaysia photo shows the "Phobaeticus chani", the world's longest stick insect

Jeanna Bryner
livescience.com – Wed Apr 21, 8:10 pm ET

An eccentric bunch of species have recently come out of hiding in the rainforests of Borneo, including the world's longest known stick insect - think two skinny pencils end-to-end, a slug that shoots "love darts," and a color-changing frog, scientists announce today.

The new WWF report details the 123 newly identified species that have been discovered since February 2007 when the three countries that make up Borneo agreed to conserve 85,000 square miles (220,000 square kilometers) of tropical rainforest, designated as the Heart of Borneo (HoB).

That's a rate of discovery of three species per month. Previously, scientists have estimated that there are about 2 million known species of life on Earth, and anywhere from 5 million to 100 million species that remain undiscovered.

"As the past three years of independent scientific discovery have proven, new forms of life are constantly being discovered in the Heart of Borneo," said Adam Tomasek, who leads the WWF project.

Here's an introduction to the new gang:

Longest insect - Measuring more than 1.6 feet (0.5 meters) in length, the world's longest stick insect, called Phobaeticus chani, was found near Gunung Kinabalu Park, Sabah. So far, only three specimens of the species have been found, all in the Heart of Borneo.

Fiery snake - Kopstein's Bronzeback snake (Dendrelaphis kopsteini) is about 5 feet (1.5 meters) long. Its neck is colored a bright orange, which fuses into an iridescent and vivid blue, green and brown pattern that extends the entire length of its body.

Color-changing frog - Called Rhacophorus penanorum, this small frog species, whose males grow to just 1.4 inches (3.5 centimeters), was discovered in Gunung Mulu National Park, Sarawak, in the Heart of Borneo. Also called the Mulu flying frog, the amphibian has a small pointed snout and is unusual in that the species has bright green skin at night but changes color to display a brown hue during the day. Its eyes follow suit to change color as well. And while the minute animal may not fly with the birds, it uses its webbed feet and aerodynamic flaps of skin on the arms and legs to glide from tree to tree.

Spectacled bird - Named because of its prominent eye-rings, the spectacled flowerpecker has a grey body with bright white arcs above and below its eyes, a white throat and white tufts at the breast sides. Scientists think the flowerpecker is a canopy specialist, feeding off fruits high in tree canopies.

Ninja slug - This green and yellow slug (Ibycus rachelae) was discovered on leaves in a mountain forest at altitudes up to 6,233 feet (1,900 meters) in Sabah, Malaysia. The slug sports a tail that's three times the length of its head, which it wraps around its 1.6-inch-long (4 cm) body as if a pet cat. In fact, its discoverers initially planned to name the slug Ibycus felis, after its feline inspiration. Instead, they named it after the girlfriend of one of its discoverers, Menno Schilthuizen of the Netherlands Centre for Biodiversity 'Naturalis.'

Maybe there's more to the name than meets the eye: The slug species makes use of so-called love darts. Made of calcium carbonate, the love dart is a harpoon-like structure that pierces and injects a hormone into a potential mate. The dart could increase the slug's chances of reproduction.

"The distinction between slugs and snails is not so strict in that part of the tropics, because most of the slugs, including the new one we described, are semi-slugs meaning they still have a shell but the shell is so small that it can't retract its body into it," Schilthuizen told LiveScience.

And though they've found several new slug and snail species, Schilthuizen said this rainforest environment isn't ideal for the animals. That's because the soil is highly acidic, which dissolves the animals' limestone shells.

Overall, the Heart of Borneo is now called home by 10 primate species, more than 350 birds, 150 reptiles and amphibians and a staggering 10,000 plants that are found nowhere else in the world, according to the new report.

To keep these species and their lush home safe from demise, under the 2007 agreement, the three governments have committed to conserve and sustainably manage the area.

http://news.yahoo.com/s/livescience/20100422/sc_livescience/worldslongestbugandninjaslugdiscoveredinborneo