Category Archives: insects

Bad Ladybug

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

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.


Vegetarian spider also a smarty pants

Female Bagheera kiplingi

Adult female Bagheera kiplingi eats Beltian body harvested from ant-acacia Photo/R.L. Curry

For ages, ants have had a monopoly on the coveted acacia, protecting the plant from would-be predators in exchange for shelter and food, or so they thought. Skulking in the background, and recently discovered, is an unlikely competitor of the ant — a spider. And this is no ordinary arachnid. The Bagheera kiplingi also happens to be a vegetarian, and is the first of its kind known to science.

“This is really the first spider known to specifically ‘hunt’ plants,” said Christopher Meehan of Villanova University. “It is also the first known to go after plants as a primary food source.”

The veggie-loving tendency of this jumping spider was first discovered in Central America back in 2001 by Eric Olson of Brandeis University. Since then he has teamed up with Meehan, who independently observed the jumping spider in 2007, to learn more about this unusual creature and the extent to which it likes plants. Not only is Bagheera kiplingi the only predominant vegetarian of 40,000 known spider species with plants making up more than 90 percent of its diet, but it’s showing scientists a complex side of arachnid biology and behavior that indicates the spider’s diet is just the beginning of this animal’s surprising life history.

Bagheera defense

Adult female Bagheera kiplingi defends her nest against acacia-ant worker. Photo/R.L. Curry

Ants are aggressive defenders of the acacia plant making life difficult for outsiders who attempt to encroach on their turf. After all, they want those yummy beltian bodies all to themselves. So how is the jumping spider managing to exploit the acacia for both food and shelter?

Science is still trying to figure that out, but preliminary research shows the spiders take advantage of the invertebrate equivalent of run-down real estate, setting up residence in less-than-desirable regions of the acacia. But their ingenuity doesn’t stop there. Bagheera kiplingi are outsmarting their ant foes, said Meehan, exploiting their intelligence and agility to get around the ants. “Individuals employ diverse, situation-specific strategies to evade ants, and the ants simply cannot catch them,” he said.

As if to add insult to co-evolution, the ants may not even know when spiders are in their midst. Bagheera kiplingi literally dupes the ant by baring young that look like carbon-copies of the ants, and Meehan has reason to suspect that the spiders actually wear a sort of insect perfume that makes them smell like their would-be attackers.

More research is forthcoming, including a look at the possibility that spider dad’s help raise the babies, a virtually unheard of behavior in spider biology. In the meantime, I hear Meehan and Olson’s methods included high-definition video of these smarty-pant vegetarian spiders. Now that would be some footage to see.

Meehan and Olson’s study is available in the October 12 issue of Current Biology.


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.


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