Tuesday, November 27, 2007
Sunday, November 25, 2007
What if we could instead use material that is already considered waste - lie used paper of scrap wood? The article below shows have termites and their lovely symbionts may point towards a solution of this kind:
ScienceDaily (Nov. 25, 2007) — Termites -- notorious for their voracious appetite for wood, rendering houses to dust and causing billions of dollars in damage per year -- may provide the biochemical means to a greener biofuel future. The bellies of these tiny beasts actually harbor a gold mine of microbes that have now been tapped as a rich source of enzymes for improving the conversion of wood or waste biomass to valuable biofuels.
Wednesday, November 21, 2007
The term "bug" is being used liberally here, but what were are talking about are:
"Eurypterids, or ancient sea scorpions, are believed to be the extinct aquatic ancestors of today's scorpions and possibly all arachnids, a class of joint-legged, invertebrate animals, including spiders, scorpions, mites and ticks."
This fossil find is truly remarkable. Giant Carboniferous dragonflies have some competition in town!
The full article is here:
Thursday, November 15, 2007
On the heels on me mentioning th robot bee used to test the Waggle Dane Hypothesis in class, here is another interesting robo-insect interactions! An excerpt:
"A robotic cockroach can act as a 'pied piper' to its flesh-and-blood counterparts, persuading the real insects to hide in unusual places.
European scientists introduced tiny autonomous robots into an "arena" where cockroaches were allowed to run free.
They wanted to see whether the robots would be accepted by the insects and whether they could influence their collective decision-making process.
The results were reported in the academic journal Science.
The robots - built by Jose Halloy, from the Free University in Brussels, Belgium, and colleagues - do not look at all like cockroaches.
But by covering the robots in filter paper infused with cockroach pheromones, the researchers were able to fool the
animals into thinking the automatons were genuine members of their group."
The rest of the article can found here:
Monday, November 12, 2007
By CARL ZIMMER
Published: November 13, 2007
An interesting article in the New York Times about studying swarms. The two parts I found most interesting were the parts where they got computer models to correctly mimic insect swarms, and when they were able to do the same thing with humans.
Here is an excerpt:
"In the case of army ants, Dr. Couzin was intrigued by their highways. Army ants returning to their nest with food travel in a dense column. This incoming lane is flanked by two lanes of outgoing traffic. A three-lane highway of army ants can stretch for as far as 150 yards from the ant nest, comprising hundreds of thousands of insects.
What Dr. Couzin wanted to know was why army ants do not move to and from their colony in a mad, disorganized scramble. To find out, he built a computer model based on some basic ant biology. Each simulated ant laid down a chemical marker that attracted other ants while the marker was still fresh. Each ant could also sweep the air with its antennas; if it made contact with another ant, it turned away and slowed down to avoid a collision.
Dr. Couzin analyzed how the ants behaved when he tweaked their behavior. If the ants turned away too quickly from oncoming insects, they lost the scent of their trail. If they did not turn fast enough, they ground to a halt and forced ants behind them to slow down. Dr. Couzin found that a narrow range of behavior allowed ants to move as a group as quickly as possible.
It turned out that these optimal ants also spontaneously formed highways. If the ants going in one direction happened to become dense, their chemical trails attracted more ants headed the same way. This feedback caused the ants to form a single packed column. The ants going the other direction turned away from the oncoming traffic and formed flanking lanes."
Sunday, November 11, 2007
Bites Recruit Wasp Workers
March 27, 2006
By Joel Schwarz, University of Washington
If you think you’ve got a bad boss, one who loves to chew people out, or if you work with backstabbing co-workers, be thankful you are not a wasp.
If you were, chances are your nestmates might bite you to communicate that it is time to leave the nest and forage for the colony, according to research by a University of Washington animal behaviorist. Biting is a way that workers in a colony of the social wasp Polybia occidentalis recruit new foragers to gather water, food and building material in a time of need, said Sean O’Donnell, a UW associate professor of psychology.
O’Donnell previously found that biting appears to be an important way of regulating the division of labor among these insects. Now, in the March 2006 issue of the journal Animal Behaviour, he describes an experiment in which he artificially removed active foragers from four wasp colonies to see how new foragers are recruited.
He found that biting was directed at certain individuals, who previously hadn’t left the nest, to induce them to begin foraging. The rate of being bitten increased by an average of 600 percent for these recruited foragers, while biting rates did not increase for other workers.
“The fact that biting was specifically directed at recruited foragers shows that biting is the mechanism that the colonies used to activate new foragers,” said O’Donnell. “With no water, food and building material coming in to the nest, the colonies needed to ramp up their foraging workforce. This study shows that these biting interactions play a central role in recruiting foragers and that biting has a role in communication that affects task performance in a colony.”
To study the wasps, O’Donnell first collected and anesthetized an average of about 300 workers from each of the colonies. He then marked each wasp’s thorax with a color-coded system that made it possible to identify individuals and returned the insects to their nests. A day later, all foragers returning to a nest were removed for at least two hours and until none arrived for at least one hour of continuous monitoring.
“The rate of foraging slowed down and stopped completely, placing stress on the colony because materials the colony needs, primarily food, are not coming in. So the colony needs to recruit new workers to make up for the loss,” O’Donnell explained.
On the final day observers watched each colony, noted the behavior of the marked individuals to see which insects were foragers, and recorded all biting interactions.
O’Donnell said the biting did not always provoke an individual to begin foraging immediately, noting the biting seems to have a cumulative effect. Some insects were bitten multiple times for hours before leaving the nest to forage.
“Going off the nest to forage, where they are exposed to all kinds of stresses and dangers, is probably the biggest change these animals face in their lives,” he said.
O’Donnell plans future studies to learn what determines which members of a colony are doing the biting and which are being bitten. He suspects that biting recipients are recognized based on something chemical on their body surface, as well as by an age component.
O’Donnell and other scientists study social insects looking for clues about how social behavior evolved and how it is maintained since there are elements that are shared among all social animals. Social aggression is one such characteristic that is almost universal among animal groups ranging from insects to primates including humans.
The National Science Foundation funded the research, which was conducted in Costa Rica.
Press Release © 2005, Joel Schwarz, University of Washington
“Polybia wasp biting interactions recruit foragers
following experimental worker removals,” Sean O’Donnell, Animal Behaviour, Volume 71, Issue 3, Pages 709-715 (March 2006) (published online February 7, 2006)
Sean O’Donnell, University of Washington
Video of Polybia nest
Back to Research 2006
Polybia occidentalis recruits new forager (marked with pink) with a bite.
Photo © 2006 University of Washington
Polybia occidentalis workers
Photo © 2006 University of Washington