RI, MA EHS Pest Control Blog

Insects Watch Skies to Navigate

How do insects such as butterflies, locusts and fruit flies navigate thousands of miles so precisely with only the unchanging sky in the foreground? Researchers now have an answer.

"If you go out in a field, lie on your back and look up at the sky, that's pretty much what an insect sees," said study co-author Michael Dickinson, a University of Washington biology professor. Peter Weir, doctoral student at the California Institute of Technology (Caltech), and Dickinson examined the behavior of the fruit fly, in outdoor lighting conditions, to find answers, the journal Current Biology reports. They demonstrated that fruit flies, equipped with complex compound eyes, keep their bearings by using the polarisation pattern of natural skylight, some of them for thousands of miles, according to Caltech-Washington statement.

Demonstrating that fruit flies can navigate using cues from natural skylight makes it easier to use genetics to better understand the complex capability and exactly how it is implemented in the brain. For millennia, seafarers have depended on the sun to know their position in the world, but often the sun is not visible. Polarisation vision solves that problem, Dickinson said, because if there's even a small patch of clear sky in a fruit fly's very broad range of view, then the natural light patterns can provide location information.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

The U.S. air force is studying fruit flies to mimic swarming behavior for military needs.

The US Air Force is engaged in wacky research on fruit flies maneuvering within a heavily instrumented "simulation tunnel" in order to develop tiny, potentially murderous insect-sized flying robots.

According to a statement issued yesterday by the Air Force Office of Scientific Research (AFOSR), research underway at in Californian labs will teach military designers how to build tiny robot aircraft which can fly around indoors or in built-up areas the way flies do.

"This work investigates sensory-motor feedback mechanisms in the insect brain that could inspire new approaches to flight stabilization and navigation in future insect-sized vehicles for the military," said Dr Willard Larkin of AFOSR.

Dr Andrew Straw of Caltech, leading the project for the Air Force, has built a special arena for his test flies to aviate around in, with video walls allowing a simulated environment to be presented to the fly. The insect test subject is tracked using a cunning multi-camera system.

"We developed a 3D fly tracking system which was our most significant technical challenge: localizing a fly in 3D nearly instantaneously," says Straw. "Next, we developed visual stimulus software capable of making use of this information to project virtual edges and textured floors in which we could modify the fly's sensory-motor feedback mechanism."

According to the AFOSR:

"The scientists have found that, counter to earlier studies suggesting that insects adjust their height by measuring the motion beneath them as they fly, flies in fact follow horizontal edges of objects to regulate altitude. Remarkably, this edge following behavior is very similar to a rule they use for steering left and right and always turning towards vertical edges."

If Straw and his colleagues can work out the rules the flies use to navigate - thought to be primarily visually based - it could be possible to design control systems for so-called Micro Air Vehicles (MAVs, small robot aircraft already in development) which would let them maneuver in places where there is no GPS signal.

Then the dark/exciting future shown in the vid above could become reality, with tiny military swarm droids scattering across towns or cities to locate or spy on persons of interest to the US authorities. They might even, as shown in the vid at around three minutes, be able to land on the back of your neck and blow your head off using some kind of tiny warhead.

Amazing what they can do nowadays.

By Lewis Page
Posted in Rise of the Machines, 8th December 2010 17:00 GMT

Fruit flies could unlock mystery of Alzheimer's, Parkinson's
By Mary Saner

Scientists look to insects for answers on how human brain forms and retains memories.  At Scripps Research Institute in Jupiter, Florida, scientists are working to find clues about how the human brain processes memories. Their laboratory test animal is not a chimp or a dog or a rat — animals that we know can remember things — it is the common fruit fly.

"They're relatively simple," Ron Davis says, explaining why the fruit fly's brain has some ideal properties for human brain research. "The brain of the fruit fly has about 100,000 neurons. The brain of a human has about 100 billion neurons, and that's an enormous network of interconnected neurons in the human brain, if one thinks about it. We literally can't wrap our brains around the human brain yet."

Fruit fly training regimen - Davis chairs the Department of Neuroscience at Scripps Florida. He's designed an experiment in which fruit flies are trained to remember an odor associated with an unpleasant electrical shock.

It involves a series of Plexiglas tubes which have an electrifiable copper grid on their surfaces. "One puts the fly in these tubes first, passes an odor through the tube," Davis says. "Odor A shocks the animal, mild electric shock." After fresh air has been blown through the tubes to remove any trace of the first odor, a second scent is pumped in.

"Odor B passes through the tube and the animals are not shocked. That's the training where we're hoping the animals will develop an association. They'll learn that one odor is bad because it's been punished in the presence of that odor. And the other odor is okay."

Then, the flies are tested to see how well they remember which odor is which. Davis says about 90 percent do, and avoid the electric shock. The ones that don't are isolated, so their genes can be studied.

The human-fruit fly connection - Researchers can remove a fly's brain and place it — still functioning — under a microscope. They can isolate neurons that have different functions and watch them fire -or send signals- to other neurons when stimulated.

Once they identify which neurons are firing differently in the normal flies that have learned to identify the difference, they examine the mutants that don't remember the shocking odor to see how genes control the firing process.

Fruit flies have essentially the same genes as we do, just fewer of them. Davis says that correlation is what makes his research so promising.

"If we find a gene in flies that's important for a process like memory formation, that sequence of that gene is generally conserved [across species]. We can use that gene to identify a similar gene in a mouse or in humans, because they have a very, very high sequence similarity. The bases that make up the gene are very similar." He explains that is how researchers are able to identify with a very high probability in humans the vast majority of genes that exist in fruit flies.

"We're actually quite similar to a fruit fly, believe it or not," he adds with a laugh.

Generations of flies in one room - Fruit flies have a very short lifespan compared to other laboratory animals like the mouse or rat. So, with the flies mating and reproducing every two weeks, many generations of flies can be studied in a year, allowing researchers to do genetic studies quickly. And since the flies are small, hundreds of thousands of them can be stored easily and inexpensively in plastic vials.

Davis shows off a small room at the Institute, filled with vials of fruit flies — all to be used in the search for answers to how our memories are made and stored.

"If one examines the vast majority of neurological diseases — Alzheimer's, Parkinson's and so forth, and psychiatric diseases — schizophrenia, bipolar disorder, ADHD, autism, all of these have a commonality in that they have learning disorders, in general, or memory formation seems to be an underlying feature of the vast majority of neurological and psychiatric diseases."

Davis and his team of researchers hope their work will lead to a drug that will help the brain fight learning- and memory-related diseases. He says gaining a fundamental understanding of how the learning process works could be the key to treating — and perhaps curing — them.