Staying on top of all the latest ag technology, field data and research can be overwhelming. That’s why the Soybean Research & Information Initiative, formerly the Plant Health Initiative, continually provides you with access to expert information and news about soybean pests, diseases, and agronomics. The aim of this check off-funded website is to communicate the on-going progress and current understanding coming from your active and wide-ranging U.S. soybean research programs. Please visit often!

RESEARCH HIGHLIGHTS

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Soybean Entomology in the North Central Region: Management and Outreach for New and Existing Pests
Mon, July 18, 2016
by Kelley Tilmon, Field Crop Entomologist, Ohio State University

Our interdisciplinary entomology and plant breeding team, comprised of 18 research and extension scientists in 12 states, has a long history of working together to solve insect problems of regional importance in soybean. Although our recent efforts have been focused on soybean aphid (Aphis glycines), our new NCSRP-funded collaborative project includes research on several new or emerging pests of soybean in the north-central region which deserve attention, particularly native and introduced stink bugs.
 
Insect Monitoring and Management

Economically damaging populations of native stink bugs are becoming more common in several states, and the introduced brown marmorated stink bug (Halyomorpha halys) is spreading rapidly in the Midwest. For example, in Ohio, where it has been in the region the longest, some locations have experienced up to 30% yield loss from this pest.



This summer we are sampling for stink bugs in seven states (IN, MN, MO, NE, ND, OH, and SD).  We are also testing a protocol for sampling stink bug stylets for the presence of yeasts and bacteria that may be transmitted to soybeans — and which could exacerbate the damage from feeding alone.

In a second set of field sites we are monitoring pollinator diversity. There is increasing evidence that soybean yield increases when plants are visited by pollinators, despite being bred for self-fertilization. This improvement varies between 6% to 18% depending upon type of pollinators present.

Thrips (Sericothrips variablilis) have always been present in soybean fields at low levels, but we now consider them an emerging pest because of their ability to transmit soybean vein necrosis virus.  While a massive research effort on such an emerging pest is not yet practical, we are doing the background work necessary for future management recommendations
— in 2016 we are monitoring thrips populations in IA, IL, IN, MI, MN, and WI.

Soybean Aphid Update
Aphid monitoring will continue this summer through the North Central IPM Regional Soybean Aphid Suction Trap Network. The 2015 fall trap data predicted a small 2016 spring egg hatch and fewer aphids this summer. We compiled the suction trap data from 2001 to 2014 and will make it available on the University of Michigan Kellogg Biological Station website.


Progress in the development of aphid-resistant soybean varieties is steady. We have begun to backcross the aphid resistance genes Rag4 and Rag6 into the same MG group I and II  backgrounds that we used to backcross Rag1, Rag2, and Rag3.  New information on genetic markers close to these genes will be used to verify the presence of Rag4 in backcross material. Germplasm with all combinations of Rag1, Rag2 and Rag3, including the three way pyramid, is being tested this summer in four states. 

Yields of several experimental lines with Rag1, Rag2 or both genes combined are being evaluated this season in a second year of uniform tests. The experimental line LD12-12701a, which has both Rag1 and Rag2, performed well in the MGII 2015 SCN Preliminary Tests. This line is being licensed for increase and possible commercialization pending its performance in 2016 yield tests. The University of Illinois soybean breeding program previously licensed three lines with Rag2 and one with Rag1 that are currently under commercial production.

To determine the economic return from planting soybean resistant varieties, we established large experimental plots this summer which will be sampled over three growing seasons —  from 2016 through 2018. 

Please check back for more updates and results from these projects
we will be posting them over the coming year. For the latest information and management recommendations on aphids, thrips and stink bugs, please read Soybean Aphid Field GuideSoybean Vein Necrosis VirusBrown Marmorated Stink Bug and view the Focus on Soybean webcasts on the Plant Management Network website. Search for soybean aphid.