Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ants protect plants better when jacked up on nectar

02.08.2004


As ants roam around on a plant, they can help their leafy companion by killing any herbivores they find. Ants often do just that, because many ants need meat in their diets.



Some species of ants are more aggressive than others, and many plants don’t have any choice about which species visit.

Researchers report for the first time that when plants supply ants with nectar, it boosts the ants’ desire for meat, potentially making them better bodyguards for the plant.


"If you have enough birthday cake or soda pop, you’re eventually going to want something of substance," said team leader Joshua A. Ness, an ecologist at the University of Arizona in Tucson.

The same is true of ants, he said. And the most convenient protein packets for ants on plants are often insects that are there to munch on the plant.

Nectar isn’t just found in flowers. Many plants exude nectar from little pores on the plant, called extrafloral nectaries, that attract ants.

"The plant wants ants to be protein eaters while they are on the plant," said team member Judith L. Bronstein, a professor in UA’s department of ecology and evolutionary biology. "The plant gets them really jacked up on carbs so they’re desperate for protein."

Ness’s presentation on the team’s findings, "Contrasting the diet and aggressiveness of the ant bodyguards tending an extrafloral nectary-bearing plant," will be given at 10:10 a.m. on Wednesday, Aug. 4, in Room D135 of the Oregon Convention Center in Portland, Ore., at the annual meeting of the Ecological Society of America. Ecologist William F. Morris of Duke University in Durham, N.C., is also a team member. The research was funded by the National Science Foundation and the National Institutes of Health.

Ness and his colleagues study mutualisms, beneficial partnerships between species. In this case, the team studied the behavior of four species of ants that visit extrafloral nectaries on a common Sonoran desert plant known as barrel cactus, or Ferocactus wislizeni.

The carbohydrates and water supplied by the cacti are not readily available to ants elsewhere, Bronstein said.

In one experiment, the researchers sealed up the nectaries with rubber cement to see if the ants would abandon a nectary-free cactus. "The ants were very put out and pulled off the rubber cement to get at the nectar," Bronstein said. "By hook or by crook, they will be going up there to get that nectar."

The ants clearly treasure the nectar available from the cacti. The researchers wanted to know what kind of value the ants gave the plant in return.

To see whether ants ate more meat when exposed to sugar, the researchers put baits of sugar and of meat at the base of barrel cactus plants and at the base of plants without extrafloral nectaries. For all four species, ants foraging by the cacti had a stronger preference for meat than did the same species of ants when foraging near other plants.

However, the ant species differed in the strength of their preference for meat.

To see how that might translate into plant protection, the researchers put caterpillars on cactus plants and measured how quickly each ant species recruited its fellows to the fresh meat and how many ants it took to vanquish five caterpillars in 30 minutes.

Within five to 15 minutes, ant numbers rapidly increased, and ants were dismembering caterpillars. But although all four ant species were equally good at recruiting their kindred to attack caterpillars, the species differed in their effectiveness at killing. Ant species that had shown greater preferences for meat in the previous experiment were also better protectors.

Even so, all four species did kill some caterpillars, so hosting even the wimpiest ant species was better for the plant than having no ants at all. The researchers also found that numbers matter: a lot of the wimpy ants could eventually do as good a job of protection as a few of the more aggressive ants.

In addition, the results suggest that loading up a mild-mannered ant on nectar makes the ant better at plant protection by increasing its cravings for meat.

Ness said, "If you pay your bodyguard up front, he or she could abandon you later, in your time of need. Here the act of collecting the reward makes the performance of the service more likely. No one has shown that before with ant bodyguards."

Mari N. Jensen | EurekAlert!
Further information:
http://www.arizona.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>