Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Insect infestation models may shed light on insect and disease outbreaks


Models of Larch budmoth outbreaks in the European Alps may eventually show scientists how to model a variety of disease and insect eruptions that rely on a combination of enemy, host and spatial movement to decimate populations, according to a team of ecologists.

"We use theoretical models to help understand the spatial component in these outbreaks and to predict how spatial spread occurs," says Dr. Ottar N. Bjornstad, assistant professor of entomology and biology at Penn State. "With local outbreaks we expect a complex spread of pest species through the landscape, here, the species spreads in waves."

The Larch budmoth feeds on larch trees, a common evergreen variety, consuming the needles and defoliating the branches. In the European Alps, the infestation moves as predictable waves from west to east completely defoliating forests beginning in the French and Italian Alps and moving across the continent through Switzerland and into Austria.

Bjornstad; M. Peltonen and A.M. Liebhold of the U.S. Department of Agriculture, and W. Baltensweiler, retired from the Swiss Institute of Technology, Zurich, report in today’s (Nov. 1) Science that "forty years of detailed surveys of defoliation caused by the Larch budmoth testify to conspicuous waves in the space-time dynamics of this system.

Creating models that predict this wave spread required consideration of the pest, its parasites, and the geographic distribution of the Larch. The historic pattern of Larch outbreaks is outbreaks that occur about every nine years and last for three to four years. The researchers confirmed that the spread of the outbreaks occurred in traveling waves and that space-time models accurately predict the geographic spread and timing of the outbreaks.

The Larch budmoth never dies out in any area of the Alps even though it totally defoliates an area. A small number of insects remain, feeding off resources left behind. While the larch trees recover, the budmoth population is kept in check by parasitic wasps that lay their eggs in the budmoth larvae. When the larva pupates, rather than a moth appearing, the adult form of the wasp emerges. Eventually, as resources improve, the budmoth population increases to reach pest levels and, because the larvae totally defoliate an area, the outbreak moves on and travels in waves through the Alps moving 125 to 186 miles per year.

"We managed to make a theoretical spatial and temporal model of the interaction between the pests, in this case the Larch budmoth, the enemy parasitic wasp and the food supply," says Bjornstad. "Generating simple geographic models allows us to predict the spatial nature of the outbreak."

The Penn State researcher notes that only with the use of fast, large cluster computers that can address spatially complex equations could this work be done. The models may be locally simple, but as the area covered increases, the dynamics become extremely complex. Unfortunately, a template does not exist to model the behavior of insects like this or human diseases that also spread in similar ways.

"We are currently working to generalize the model framework to other pest systems," says Bjornstad. "With human diseases, for example, modeling the movement of people is different and more complex than modeling the movement of moths."

While a general model will probably not be possible, a class of models researchers could use to predict insect outbreaks as well as disease epidemics such as smallpox, and measles in humans or foot-and-mouth disease in domestic animals, is slowly emerging. In each case researchers must develop a deep understanding of the specific local interactions between the pest and its resource.

"The emerging picture is that if you understand the local interactions and use a class of models that embed these on maps, you can make really good predictions," says Bjornstad.

In essence, the researchers are developing a methodology for creating models that are applicable to infectious diseases in humans, animals and plants as well as insect outbreaks. Bjornstad is currently finalizing other research on human pathogens using very similar methodology.

"The key to understanding the spatial network of disease spread for humans is more difficult," Bjornstad says. "Human movement patterns are more complex so the models have to be tweaked in each system to accommodate these differences. However, the overall methodology can model spatial outbreaks whether insect or human."

Andrea Messer | EurekAlert!
Further information:

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: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>