Updated February 14, 2022:
Note: The progress towards the goals, objectives, and deliverables in this project are for the final report but only reflect 2 of 3 years of this project as it was merged with another multi-state NCSRP project with Kelley Tilmon.
1) Determine the distribution and severity of soybean gall midge across the north-central region
Extensive field surveys of soybean gall midge were conducted across nine states (ND, MN, SD, IA, NE MO, KS, and IL) in 2020. Three additional states (IN, OH, and MI) could not conduct field surveys due to Covid-19. A total of 1,745 fields were surveyed across 267 counties for the presence of soybean gall midge. Results from the survey found that there were no new state records; however, soybean gall midge was found in new counties in all five of the existing states, with a total of 19 new counties. The greatest number of new counties was NE(8), followed by IA(5), SD(3), MN(2), and MO(1). In Nebraska, significant and extensive sampling took place across the east and central part of the state, with 257 fields sampled. Results showed that larval number per plant and injury was concentrated to the east-central portion of the state. An initial analysis of potential factors for larval presence and plant injury shows that distance from last year’s soybean field, the proximity to dense vegetation along field borders, and the percent soybean in an area around the sample were the leading causes.
In 2021, no funding was available to detect soybean gall midge in new states through field surveys; however, tens of thousands of postcards were sent out to several states as a result of Michigan redirecting its funding towards awareness. In the existing states, efforts were made to continue to document the presence of soybean gall midge. In total, 26 new counties were identified with the greatest number of new counties occurring in MN(13), NE(8), IA(4), and SD(1). In NE, an increased understanding of the biology of soybean gall midge combined with the use of USDA CropScape greatly enhanced the likelihood of finding it in low frequency. This technique will be applied to other states for surveys in 2022. Maps for the detection of soybean gall midge were updated at frequent intervals on the soybeangallmidge.org website. In the last two years, over 3,780 people have viewed the distribution page on the website.
The results of the past two years combined with reports back to 2018 found that soybean gall midge is present in 140 counties across five midwestern states. This area encompasses approximately 16 million acres of soybean. However, only a small portion of this area is under significant threat from soybean gall midge, although its distribution and severity vary between years.
2) Determine the emergence timing and source of adult soybean gall midge.
Extensive efforts have been made to document the timing and source of soybean gall midge adult emergence. Over the past two years, a total of 64 sites across four states were monitored for adult emergence of soybean gall midge. At two sites in Nebraska, field sites have had a large number of cages placed in the field and surrounding area to determine the source of soybean gall midge overwintering adults. Both years showed the same result, that the vast majority (>98%) of adults emerged from last year’s soybean field with a very small portion from the field border. No detection of adults occurred from fields that were corn the previous year (soybean two years prior). In total, 10,394 adults were collected over the two seasons with 5,118 in 2020 and 5,276 in 2021. First emergence of soybean gall midge has typically occurred in mid-June for the last couple years (2019: June 14 and 2020: June 10); however, the emergence network collected adults on May 31 in 2021. Emergence timings and duration of soybean gall midge has provided critical insights in the difficulties of managing this new pest with the overwintering duration increased from 25 days in 2020 to 36 days in 2021. This long duration of overwintering emergence implies that it will be difficult to control soybean gall midge with any single foliar application.
3) Screen soybean varieties for resistance or tolerance to soybean gall midge.
After two years of testing, a total of four of the eight environments resulted in significant pressure for soybean gall midge. Three of the four sites had two layers of data relating to the presence or absence of larvae and a rating on the proportion of dead or dying plants. An analysis of these three sites, which had greater than 98% of plots infested, was that there was a wide range of injury scores, indicating differential response to infestation from soybean gall midge. Of the 713 genetically diverse accessions from the USDA Soybean Germplasm Collection, approximately 40 accessions had less than 6% dead plant, 114 accessions had 12% dead plants, 350 accessions had 25% dead plants, and 15 had 60% of greater dead plants. This distribution shows the predominance of more resistant reactions to soybean gall midge. The Manhattan plot from GWAS shows that significant SMP was identified on all soybean chromosomes except 1, 3, and 12. These results are very promising but further data will be needed. As the project moves towards the identification of commercial germplasm with resistance, there will be a need to evaluate lines for yield. To date, evaluations have been based on differences in mortality of plants; additional steps will be needed to determine if yield losses occur without mortality from soybean gall midge feeding.
4) Disseminate information to stakeholders on current information and management for soybean gall midge.
A broad array of technology and platforms have been used to disseminate information on soybean gall midge using both traditional and innovative tools. Over the past two years, approximately 100 talks have been given in either virtual or in-person format to over 7,600 participants. Additional dialogue was created through the use of a roundtable with clientele and a regional soybean gall midge webinar series, both of which received very positive reviews. Traditional dissemination was done through the release of three extension guides (NE, ND, and IA) as well as numerous articles during the season. In addition, a seminal publication on soybean gall midge was accepted in the Journal of Integrated Pest Management. Rapid dissemination for management of soybean gall midge was achieved through the use of an alert system in conjunction with a new website, soybeangallmidge.org. This system has been very successful and well-received by clientele which is evident with a 40% increase in participants for the alert system in a year and over 5,000 visitors to the website.
View uploaded report
Extensive field surveys of soybean gall midge were conducted across nine states (ND, MN, SD, IA, NE MO, KS, and IL) in 2020. Three additional states (IN, OH, and MI) could not conduct field surveys due to Covid-19. A total of 1,745 fields were surveyed across 267 counties for the presence of soybean gall midge. Results from the survey found that there were no new state records; however, soybean gall midge was found in new counties in all five of the existing states, with a total of 19 new counties. The greatest number of new counties was NE(8), followed by IA(5), SD(3), MN(2), and MO(1). In Nebraska, significant and extensive sampling took place across the east and central part of the state, with 257 fields sampled. Results showed that larval number per plant and injury was concentrated to the east-central portion of the state. An initial analysis of potential factors for larval presence and plant injury shows that distance from last year’s soybean field, the proximity to dense vegetation along field borders, and the percent soybean in an area around the sample were the leading causes.
In 2021, no funding was available to detect soybean gall midge in new states through field surveys; however, tens of thousands of postcards were sent out to several states as a result of Michigan redirecting its funding towards awareness. In the existing states, efforts were made to continue to document the presence of soybean gall midge. In total, 26 new counties were identified with the greatest number of new counties occurring in MN(13), NE(8), IA(4), and SD(1). In NE, an increased understanding of the biology of soybean gall midge combined with the use of USDA CropScape greatly enhanced the likelihood of finding it in low frequency. This technique will be applied to other states for surveys in 2022. Maps for the detection of soybean gall midge were updated at frequent intervals on the soybeangallmidge.org website. In the last two years, over 3,780 people have viewed the distribution page on the website.
The results of the past two years combined with reports back to 2018 found that soybean gall midge is present in 140 counties across five midwestern states. This area encompasses approximately 16 million acres of soybean. However, only a small portion of this area is under significant threat from soybean gall midge, although its distribution and severity vary between years.
Extensive efforts have been made to document the timing and source of soybean gall midge adult emergence. Over the past two years, a total of 64 sites across four states were monitored for adult emergence of soybean gall midge. At two sites in Nebraska, field sites have had a large number of cages placed in the field and surrounding area to determine the source of soybean gall midge overwintering adults. Both years showed the same result, that the vast majority (>98%) of adults emerged from last year’s soybean field with a very small portion from the field border. No detection of adults occurred from fields that were corn the previous year (soybean two years prior). In total, 10,394 adults were collected over the two seasons with 5,118 in 2020 and 5,276 in 2021. The first emergence of soybean gall midge has typically occurred in mid-June for the last couple of years (2019: June 14 and 2020: June 10); however, the emergence network collected adults on May 31 in 2021. Emergence timings and duration of soybean gall midge have provided critical insights in the difficulties of managing this new pest with the overwintering duration increased from 25 days in 2020 to 36 days in 2021. This long duration of overwintering emergence implies that it will be difficult to control soybean gall midge with any single foliar application.
After two years of testing, a total of four of the eight environments resulted in significant pressure for soybean gall midge. Three of the four sites had two layers of data relating to the presence or absence of larvae and a rating on the proportion of dead or dying plants. An analysis of these three sites, which had greater than 98% of plots infested, was that there was a wide range of injury scores, indicating differential response to infestation from soybean gall midge. Of the 713 genetically diverse accessions from the USDA Soybean Germplasm Collection, approximately 40 accessions had less than 6% dead plant, 114 accessions had 12% dead plants, 350 accessions had 25% dead plants, and 15 had 60% of greater dead plants. This distribution shows the predominance of more resistant reactions to soybean gall midge. These results are very promising but further data will be needed. As the project moves towards the identification of commercial germplasm with resistance, there will be a need to evaluate lines for yield. To date, evaluations have been based on differences in mortality of plants; additional steps will be needed to determine if yield losses occur without mortality from soybean gall midge feeding.
A broad array of technology and platforms have been used to disseminate information on soybean gall midge using both traditional and innovative tools. Over the past two years, approximately 100 talks have been given in either virtual or in-person format to over 7,600 participants. Additional dialogue was created through the use of a roundtable with clientele and a regional soybean gall midge webinar series, both of which received very positive reviews. Traditional dissemination was done through the release of three extension guides (NE, ND, and IA) as well as numerous articles during the season. In addition, a seminal publication on soybean gall midge was accepted in the Journal of Integrated Pest Management. Rapid dissemination for management of soybean gall midge was achieved through the use of an alert system in conjunction with a new website, soybeangallmidge.org. This system has been very successful and well-received by clientele which is evident with a 40% increase in participants for the alert system in a year and over 5,000 visitors to the website.