Bad Ladybug

Different types of Harlequin ladybug, a rapidly spreading invasive pest. ©Entomart

Ladybugs, once the championed protectors of backyard gardens, are showing spots of a less flattering color, and their public image looks like it could be taking an even bigger turn for the worse. A new study has found that invasive Harlequin ladybugs crossbreeding with a species of flightless ladybugs are creating a super strain of a buggy pest.

In recent years, ladybugs have taken their voracious appetites around the world, and they don’t just gobble up target insects. Couple this with plagues of ladybugs infesting homes, and you’ve got an unseemly problem on your hands.

To fight their spread, flightless ladybugs were released as a biological control agent. The idea being that the walk-only ladybugs wouldn’t spread as far as quick. Harlequin’s aren’t to be put off it would seem. The two types of ladybugs can hybridize, giving rise to offspring that are larger, faster-growing, and generally more robust than either of its parent species. Preliminary research suggests that the cross-bred young are even better-equipped to deal with starvation.

The findings by BenoÎt Facon of UMR Centre de Biologie et de Gestion des Populations in Cedex, France, and his colleagues are just a beginning. Researchers want to test multiple generations of hybrid and subject them to different conditions to unravel the magnitude of the Harlequin ladybug dilemma.

You can read more about their discoveries in the current issue of Evolutionary Applications.

Cane toads heart climate change

Cane Toad, AKA Bufo marinus, AKA troublemaker extraordinaire (Photo/ Eli Greenbaum)

Cane toads like it hot, and with climate change poised to raise temps in Australia, this persistent, invasive species could soon be living it up even more.

At least that’s the word coming out of new research from the University of Sydney and presented at the Society for Experimental Biology’s annual conference in Prague.

A lot of what we hear about climate change focuses on habitat loss (cue rising sea levels) or species extinction (sorry red wolf and coral reefs), but here’s another way the pesky, poisonous cane toad can flip the amphibian bird to mankind – warmer climes mean prolific times as far as the toad is concerned.

“The negative effect of high temperature does not operate in cane toads, meaning that toads will do very well with human induced global warming,” said Professor Frank Seebacher from the University of Sydney in a press release.

Many of you reading this are probably familiar with the story of the cane toad, but here’s the quick shake down. In the mid 1930s, Australian biologists, hoping to stem the onslaught of beetles ravaging cane fields, introduced cane toads to Queensland and the Northern Territory. Unfortunately, toads passed on the beetles, instead turning their appetites towards lizards, snakes and other native wildlife. To compound factors, the toads secrete a toxic substance that can do a serious number on just about anything that tries to eat it. So the cane fields now have beetles and bucket loads of poisonous toads. Sigh.

And because of research by Seebacher, we now have a good idea that toads are going to thrive even more as temperatures rise from climate change. Warmer weather makes for stronger, or at least more efficient, heart and lungs in the cane toad, Seebacher found. And if that’s not unsettling enough, the study also states “the cane toad can adapt its physiology in response to a changing environment repeatedly and completely reversibly many times during its lifetime.”

Will nothing temper their proliferation?

Before you totally throw up your hands and say, “Why do I read this if all you’re going to tell me is bad news,” here’s a ray, or sliver, of hope. Maybe, just maybe, this phenomenon will prove true for other toads, ones we actually would like to see stick around. I’ll get back to you when Seebacher conducts that study.

Changing Chesapeake Bay acidity endangers oysters

New research shows that the shell growth of Crassostrea virginica from Chesapeake Bay could be compromised by current levels of acidity in some Bay waters. (Photo/Chris Kelly, UMCES Horn Point Laboratory)

Growing up at the mouth of the Lynnhaven River in Virginia, where the river meets the Chesapeake Bay and the bay meets the ocean, I can’t tell you how many mornings I woke up and looked out my window to see neighbors wading in rubber boots, harvesting oysters from the beds just off our riverbank. For some, like my neighbors, oysters were a way to connect with the land and make a little extra dough. For others it was their livelihood. The act was something that just was. It never occurred to me that the oysters could one day be gone.

That’s why I was especially alarmed to read this new report from the University of Maryland Center for Environmental Sciences. Rising acidity levels in the Chesapeake Bay are making it harder for oysters to grow their shells. I’ve heard the news before that rising ocean acidity from sources such as carbon dioxide can spell disaster for marine wildlife, but this new study shows that acidity is rising faster in the Chesapeake Bay than in the ocean and having a measurable impact on Bay wildlife.

“With oyster populations already at historically low levels, increasingly acidic waters are yet another stressor limiting the recovery of the Bay’s oyster populations,” said marine biologist Dr. Roger Newell of the UMCES Horn Point Laboratory in a press release.

But don’t turn around to blame climate change just yet. The story is a bit more nuanced than that, though the source of the problem still has to do with us. In the saltier areas of the bay, the acidity is going up, leading to thin shell growth that makes oysters more vulnerable to predators, including crabs. But in more freshwater portions of the Bay, acidity is actually going down, said the study, which looked at more than 20 years of historical water quality data from the Bay.

The difference seems to be not atmospheric carbon dioxide, but the base of the food chain. In freshwater areas along the upper Chesapeake, sewage and agricultural runoff cause phytoplankton blooms, which consume carbon dioxide and lower acidity, said the study. Sounds good at this point right? Here’s the catch. As phytoplankton drift through the Bay, they are eaten by animals and other bacteria, releasing the carbon dioxide that the plankton so diligently consumed in the first place. This carbon dioxide lingers in the water, leading to spikes in acidity in the saltier regions of the Bay near the ocean.

“While these variations in acidity may improve conditions for shellfish in some areas, they may also magnify detrimental impacts in others,” said lead author Dr. George Waldbusser of Oregon State University in a press release. “What our study indicates is there may be an important shifting baseline and without better measurements we will fail to fully understand impacts on estuarine biota.”

Beyond the science itself, this study highlights how connected and varied our environment is. It lays out a pathway of human-induced consequences to an ecosystem, and teaches that we need to look beyond one-to-one cause and effect. Erin Voigt, an undergraduate student who worked on the study puts it well. “The complex response of oyster shell formation to temperature, salinity, and acidity highlights the need to understand how the entire ecosystem is changing, not just acidity,” she said.

And that ecosystem includes us.

You can view the article online in the journal Estuaries and Coasts.

Dosed: Livestock scavenging vultures consume cocktail of veterinary drugs

Griffon, their name conjures images of legend and mythology, but in the skies above Spain and Portugal, thousands of real life griffon vultures survey the earth looking for their next meal. And to a griffon, nothing says “yummy” quite like a fresh pile of pork carcasses – well, maybe sheep.

Don’t knock it. They are one of nature’s best cleaner-uppers. But it turns out that griffon vultures and at least two other vulture species are ingesting something not on their carrion menu, drugs and lots of them.

Vulture numbers have soared in Europe since the 1980s, thanks in part to the common practice of carcass dumping of dead livestock, also called muladares, which provide vultures with a ready and reliable supply of chow. But in cattle, drugs abound. And lunch at a muladar promises a chemical cocktail of veterinary medicine as well as protein.

A griffon vulture soars in the skies above the Douro River in northeastern Portugal. (Photo/Morgan E. Heim)

A new study by Guillermo Blanco with Museo Nacional de Ciencias Naturales in Madrid showed that the proportion of vulture nestlings testing positive for antibiotics rose from 0 percent in 2001 to 70 percent in 2006, and now scientists are seeing a triple threat. Blanco found griffon, Egyptian and cinereous vultures, contained combinations of antibiotics, anti-parasitics and non-steroid anti-inflammatory drugs, such as aspirin, in their system, a never before seen combination in a wild animal, according to the researchers.

Scientists are still studying what this chemical cocktail could spell for the vulture, and the three species did show variance in the amounts and types of drugs found in their systems, possibly due to the differences in how they feed. But Blanco and his colleagues do mention possible reasons for why and how the drugs are building up in the birds’ bodies.

Vultures typically split mealtimes between muladares and “vulture restaurants,” scavenging from the carcasses of free-ranging livestock. Drugs abound in both food sources, but reside in much greater concentrations and types in the bodies of farm-raised cattle – farm-raised livestock require more drugs due to their compact living quarters. Recent European Union regulations aimed at curbing the spread of mad cow disease made it illegal to abandon carcasses of free-roaming cattle in the countryside. As an unintended consequence of the rule, this practice eliminated one key source of food for the vulture, concentrating food in the veterinary drug-laden muladares. The regulation has also been reputed to be a probable contributor to the vulture’s decline since 2003.

Side-effects could include increased disease, due to exposure to immuno-suppressants, changing delicate bacterial communities in the vulture’s system and a rise of infection or transmission at feeding sites.

One remedy would be to allow for carcass abandonment to resume according to the study. “There is no evidence of BSE [mad cow] transmission risk due to the abandonment of unstabled livestock carcasses in the countryside,” wrote the study authors. “Therefore, this traditional practice in the Mediterranean regions should be legally permitted in order to increase availability, dispersion and quality of food for scavengers.”

You can read more about Blanco and his colleagues’ findings in the December 2009 issue of the journal Animal Conservation.

Take two pills and buzz me in the morning

Good news for honeybee apiaries. Colony Collapse Disorder, the multi-billion dollar plague of honeybee farms and a threat to ecological well-being may be a thing of the past thanks to new discoveries by researchers out of Spain. It seems a bug has been bugging the bees in the form of a microsporidia parasite called Nosema ceranae.

Dr. Mariano Higes and his team ruled out popular suspicions of pesticides and the Israeli Acute Paralysis Virus as possible causes of the disorder,instead determining bees from the two apiaries were dying solely from infections by the pesky parasite. Subsequently, all colonies treated with the antibiotic, flumagillin, completely recovered. This marks a pretty significant breakthrough in an ecological mystery that has spanned the globe and threatened the agricultural industry.

“Now that we know one strain of parasite that could be responsible, we can look for signs of infection and treat any infected colonies before the infection spreads” said Dr Higes, principle researcher, in a press release.

The complete study can be reviewed in the journal Environmental Microbiology Reports, a new publication from the Society for Applied Microbiology.

Click the following links for a few interesting articles about Colony Collapse Disorder (Silence of the Bees, hcn.org) as well as some past research on the Nosema ceranae parasite.