Last year, aphid infestation on soybean was high enough that many growers had to spray their fields to control aphids. Despite this, many aphids survived and took flight last fall causing a public nuisance. Migrating soybean aphids have delayed Major League baseball games, closed outdoor cafes and curtailed outdoor activities.
The soybean aphid is the only soybean insect pest known to have multiple biotypes, said Glen Hartman, U of I professor of crop sciences and USDA research plant pathologist. When farmers plant aphid-resistant soybean varieties, they provide protection against Biotype 1. However, recent research indicates that Biotype 2, which was first discovered in 2006, can overcome some aphid-resistant varieties.
The most recently identified soybean aphid, Biotype 3, was discovered in Springfield Fen, Ind., on an overwintering host, glossy buckthorn. Biotype 3 has not been found outside of this location to date and is not distinguishable by its appearance.
Researchers identified Biotype 3 by testing this aphid on soybean plants with known resistance genes. They found it was capable of feeding and multiplying on varieties carrying the resistance genes Rag1 and Rag2.
"Identifying a biotype that can overcome Rag1 and Rag2 resistance, even before soybean varieties with these resistance genes were deployed in production, suggests high variability in virulence within soybean aphid populations," said Curt Hill, U of I principal research specialist. "This gives the pest a high potential to adapt to and reduce the effective life of resistance genes deployed in production."
What does this mean for soybean farmers? A limited number of soybean varieties carrying the Rag1 resistance gene were planted in 2009, and more varieties are now available. The discovery of an aphid biotype that can overcome the gene means breeders and seed companies will need to keep pace with the pest.
Hartman recommends that farmers should plant aphid-resistant varieties if they have experienced aphid problems in the past. In addition, farmers should closely monitor aphid populations in their fields and spray when populations reach the economic threshold level, approximately 250 aphids per plant. If farmers find threshold populations on resistant varieties, they should contact their local Extension agent.
Fortunately aphid infestations can easily be controlled with insecticides, Hill said. However the question of timing becomes a key factor that requires scouting of fields and entomologist recommendations regarding threshold levels. Hartman said farmers can save some of their yield if they follow guidelines found in U of I Extension literature.
"Soybean aphids have a closer relationship with their host than other bugs," Hill said. "They can feed on other plants, but they only readily reproduce during the summer months on soybean. They suck all of the life out of the plant in a matter of weeks, causing tremendous yield loss for farmers. This makes scouting crucial."
U of I researchers are continuing to look for new resistance genes while studying the genomics of the soybean aphid to better understand its virulence. Hill believes plant resistance can provide an effective, economical and sustainable method of insect control.
"We hope the use of molecular markers to identify biotypes will be available soon so we can take samples in the field and perform quick DNA tests to determine distribution of these biotypes," Hill said. "Our goal is to help the soybean seed industry determine where to market soybean varieties with particular soybean aphid resistance genes to ultimately help producers select appropriate resistant varieties based on the virulence potential in their area."
This research was published in the Journal of Economic Entomology and funded by the United Soybean Board. The research team included Curt Hill, Laura Crull, Theresa Herman, Glen Hartman and David Voegtlin at the U of I.
Digital photos available at: http://www.aces.uiuc.edu/news/News_Photos/SoybeanAphid/
Jennifer Shike | EurekAlert!
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy