Cannibal harlequin ladybirds now threaten native species with STDs

Scientists have warned about the unknown effect this fungal infection may have on the already beleaguered native population

ROSE TROUP BUCHANAN

Saturday 18 October 2014

Cannibal harlequin ladybirds are posing a new threat to Britain’s native species after scientists warned the variety was spreading a virulent sexually transmitted fungal infection.

Scottish scientists are concerned the insect fungus, which is transmitted primarily through mating, may be passed onto native species from the non-indigenous type with unpredictable consequences, the Scotsman reports.

Many harlequin ladybirds are already suffering from the Laboulbeniales fungal infection, according to studies conducted by the University of Stirling’s departments of biological and environmental sciences with the Centre for Ecology and Hydrology.

Researcher Matt Tinsley said: “The study will allow us to know where this fungus has spread to and what proportion of native and invasive ladybirds are infected.”

The number of harlequin ladybirds has greatly increased in recent years after they were first seen in the UK in 2004 when they were imported to Europe from East Asia for commercial pest control of crops.

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Mysterious Rattlesnake-Killing Infection Emerges – via Herp Digest

Wynne Parry, LiveScience Senior Writer, 2/24/2012

In south-central Illinois, rare rattlesnakes have been dying from what appears to be aggressive fungal infections that cause grotesque facial lesions.

"What is kind of scary about it is it loves the skin, but once it gets through the skin, it will invade muscle and bone and it is extremely destructive," said Matthew Allender, a wildlife veterinarian affiliated with the University of Illinois who has been studying these infections."I've never quite seen anything like this in a reptile."

Since 2008, four confirmed and two probable cases have turned up in a population of eastern massasauga rattlesnakes of about 50 to 60 individuals. (This species of snakes are candidates for listing under the federal Endangered Species Act.) Allender has tried, unsuccessfully, to treat two of these cases, but all have been fatal.

A soil-dwelling fungus, Chrysosporium, appears to be responsible. It is a not-too-distant relative of another soil fungus turned killer. Geomyces destructans was recently confirmed as the cause of white-nose syndrome, which has been decimating bat populations in the eastern U.S. after first being spotted in a cave near Albany, N.Y., in 2006.

Fungal pathogens have been increasingly associated with epidemics in wildlife, he notes in a report published in the journal Emerging Infectious Diseases in December. Amphibians around the planet have been devastated by chytridiomycosis, a fungal disease.

Allender suspects the handful of cases he's seen among the eastern massasauga rattlesnakes are just the tip of a larger phenomenon. Other biologists have told him they have seen similar infections accompanied by the fungus in rattlesnake populations in the northeastern United States.

"We are at the early stage where white-nose syndrome was four years ago, where they had all these outbreaks they were starting to see, then starting to investigate," Allender said.

The eastern massasauga rattlesnakes were once plentiful, but loss of habitat has reduced their numbers and driven them into closer quarters.

This gives rise to one possible scenario that might explain the outbreak of the disease: Once crowded together, the snakes are more likely to interact and pass the fungus to one another. Chrysosporium may also represent a new and devastating "superbug,"or there may be something in the environment that is weakening the snakes' immune systems, leaving them more vulnerable to an infection they could once fight off, Allender said.  

Allender is collaborating with biologist Michael Dreslik of the Illinois Natural History Survey Prairie Research Institute, who conducts the population surveys that have uncovered the sick rattlesnakes. This year's survey will begin in the coming month, Allender said.

Biodiversity Loss May Be Contributing to Amphibian-Killing Fungal Infection

ScienceDaily (Sep. 19, 2011) — Researchers at Oregon State University have shown for the first time that loss of biodiversity may be contributing to a fungal infection that is killing amphibians around the world, and provides more evidence for why biodiversity is important to many ecosystems.

The findings, being published this week in Proceedings of the National Academy of Sciences, used laboratory studies of amphibians to show that increased species richness decreased both the prevalence and severity of infection caused by the deadly chytrid fungus, Batrachochytrium dendrobatidis.

"With greater diversity of species, you get a dilution effect that can reduce the severity of disease," said Catherine Searle, an OSU zoologist and lead author on the study. "Some species are poor hosts, some may not get infected at all, and this tends to slow disease transmission.

"This has been shown in other systems like Lyme disease which infects humans, mice and deer," she said. "No one has really considered the dilution effect much in amphibians, which are experiencing population declines throughout the world. It's an underappreciated value of biodiversity."

It's generally accepted, the researchers said, that a high diversity of species can protect ecosystem function, help to recycle nutrients, filter air and water, and also protect the storehouse of plant or animal species that may form the basis of medicines, compounds or natural products of value to humans.

Protection against the spread of disease should more often be added to that list, they said.
"Emerging infectious diseases are on the rise in many ecosystems," said Andrew Blaustein, a co-author on this study, professor of zoology at OSU and leading researcher on the causes of amphibian declines.

"Protection of biodiversity may help reduce diseases," he said. "It's another strong argument for why diverse ecosystems are so important in general. And it's very clear that biodiversity is much easier to protect than it is to restore, once it's lost."

The fungus, B. dendrobatidis, can lead to death from cardiac arrest when it reaches high levels in its amphibian hosts. It is not always fatal at lower levels of infection, but is now causing problems around the world. One research team has called the impact of the chytrid fungus on amphibians "the most spectacular loss of vertebrate biodiversity due to disease in recorded history."

Amphibians face threats from multiple causes, including habitat destruction, pollution, increases in ultraviolet light due to ozone depletion, invasive species, and infectious disease.

The dilution effect can occur in plants and animals, but also in human diseases. In a different report published last year in Nature, researchers noted an increased risk of West Nile encephalitis in the U.S. in areas with low bird diversity. And in more diverse communities, the infection of humans by schistosomiasis -- which infects 200 million people worldwide -- can be reduced by 25-99 percent.

http://www.sciencedaily.com/releases/2011/09/110919151311.htm