This fall, the entomologists are concluding a two-year study that involved mass-rearing parasitic wasps that attack wheat stem sawfly larvae that tunnel the interior of developing wheat plants. The team includes entomologists David Weaver, master's graduate Godshen Pallipparambil-Robert and undergraduate Melissa Frazier of Kalispell.
Pallipparambil-Robert's work, as part of his completed master's degree, used large cages placed over wheat at the Post Agronomy Farm west of Bozeman. He deliberately infested the enclosed wheat with wheat stem sawflies, and then introduced the parasitic wasps. His research explored whether supplemental food provided as nectar from flowering plants or as honey water increases the number of parasitic wasps produced in each cage. Another part of his thesis project examined whether using special ultraviolet and visible light-transmitting windows increases the number of parasites.
"After two years, the research shows that the added light consistently causes small increases in the number of parasitic wasps, while the food supply is probably not important in these mass-rearing cages, because the parasitoids were added in large numbers, and attacked the available sawflies before the need to feed may have become critical " Weaver said. At lower parasitoid densities, supplemental food might be much more important, and research from other systems suggests that this is definitely true in natural settings. However, the goal of the research is to find ways to increase the supply of parasitoids from a controlled system to Montana wheat growers.
"Right now, the number of people wanting parasitic wasps far out-number what we can deliver," he said. The small, orange parasitic wasps are part of the naturally occurring suppression of wheat stem sawfly that varies greatly from field to field throughout Montana. The wasps produce two generations of offspring a year, compared to only one for the wheat stem sawfly.
A number of Montana counties now have established populations of these natural enemies in their wheat fields, thanks to pilot scale research co-sponsored by the Montana Wheat and Barley Committee; USDA, CSREES Special Research Grants; the Montana Board of Research and Commercialization Technology; and the BNSF Railway Foundation. However, the process of locating parasitic wasp populations for redistribution is inefficient, and having the ability to reliably mass produce these organisms would be an asset.
Even a slight increase in efficiency could translate into the ability to produce thousands of additional parasitic wasps, which could then be distributed to wheat stem sawfly infested sites.
Pallipparambil-Robert has just begun work on a doctorate in entomology at the University of Arkansas. The late summer and autumn efforts are being completed by Frazier. It became her job to tend the cages of parasitic wasps every few days, after Palliparambil-Robert departed.
Weaver said more research is needed to determine precisely how many sawflies and parasitic wasps need to be added to each cage and to determine the best time to add the wasps. The current research shows that enough parasitoids can be produced to establish a founding population in an infested wheat field using the straw residue from a single mass-rearing cage.
Mass-rearing of the parasitic wasps is only one of three or four approaches for sawfly management that are being pursued at MSU. The drought conditions of recent years have made the work more pressing, since drought favors damage by wheat stem sawflies, which are now more widely distributed in Montana than years ago.
"There are larger areas of sawfly damage all along the Golden Triangle, the northern tier of Montana counties as well as the area around Lewistown, Circle and Jordan," Weaver said. Currently, MSU is specifically partnering with MSU Extension county agents to redistribute and monitor populations of parasitic wasps, as part of an expanded effort to establish the more effective parasitoid populations in those areas.
"We hope to see the populations there grow, and what Pallipparambil-Robert's work will do is to help us have the ability to have parasitoids more readily available for future efforts," Weaver said. "Right now, we have to locate a large population of these beneficial insects before we can redistribute them. If we can reliably have them available at a known location, we could do our job much more efficiently."
A "how to" MontGuide for the conservation of these parasitic wasps, which supports the redistribution efforts, is currently being written and should become available over the winter.
Contact: David Weaver, (406) 994-7608 or firstname.lastname@example.org
David Weaver | EurekAlert!
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research