The Ohio State University #IPM50

For more information on IPM in the North Central Region visit www.ncipmc.org  

Transcript

Speaker 1 (00:03):
Welcome to a special Pest Central limited series celebrating the 50th anniversary of Integrated Pest Management. This collaborative effort focuses on the history and future of IPM in the North Central Region and features university faculty and agency staff interviews from around the region.
This work is supported by the USDA National Institute of Food and Agriculture and the North Central IPM Center. This podcast is edited and produced by Michigan State University Extension. MSU is an affirmative action, equal opportunity employer. Michigan state university extension programs and materials are open to all.

Jim Jasinski (00:57):
Happy 50th anniversary, IPM, from Ohio State University.

Amanda Douridas (01:03):
Happy 50th anniversary, IPM, from Ohio State University Extension. Hello all I'm Amanda Douridas with Ohio State University Extension as the Agriculture and Natural Resources Educator in Madison County, and I'm joined by Jim Jasinski. Jim, could you introduce yourself for us?

Jim Jasinski (01:23):
Sure, Amanda. I'm Jim Jasinski, Professor in the Department of Extension, and I also coordinate the IPM Program here at the Ohio State University.

Amanda Douridas (01:32):
Thanks Jim. So, tell us a little bit about how you got started in IPM.

Jim Jasinski (01:38):
Yeah, so my story goes back quite a ways to 1993, I started with Ohio state in the IPM Program, working on field crops. My job at that time mostly consisted of scouting and monitoring corn and soybean fields for key insect pests during different parts of the season. I was involved in many trials at the Western AG research station in south Charleston, doing evaluation of insecticides for corn worm control, bean leaf beetle, black cut worm, seed corn maggot, and other pests.
Around 1996, the first transgenic Bt field corn hybrids were released to universities for evaluation against caterpillar pests. At that time, primarily European corn bore, which was a significant pest in the Midwest. Bt is an abbreviation for bacillus thuringiensis, a common type of soil bacteria that produces proteins that are insecticidal to certain groups of insects, in this case caterpillars, which feed on the stalks of corn.
We had trials comparing Bt and transgenic hybrids from several companies that you might recognize like Monsanto and Northrop King. We looked at their Bts compared to their non Bt isoline. That just means the same hybrid, just minus the Bt gene. And against conventional hybrids to observe any differences between the hybrids in terms of caterpillar control or amount of damage. In some trials, we would plant both types of the hybrids Bts and non Bts and hope for natural infestations of European corn bore, which would give us data to show how effective the Bt hybrids were in terms of protecting against caterpillars. But we would also buy European corn bore larvae from a lab in Minnesota, and actually have them shipped to Ohio and then take them out of the box and put them in the field, put them on corn plants, to boost the pressure and hopefully see evidence of stock boring and then plant protection in these artificial infestations.

Amanda Douridas (03:40):
You are right in the middle of all this Bt development. That's pretty cool.

Jim Jasinski (03:46):
Yeah, at the time, it was just like one more trial to get through at the end of the day, but as it turns out, looking back almost 30 years, it was quite something. So yeah, to be involved with it, again, it just something that I never thought would be a milestone in my career that it was a big shift in AG and plant protection, but it really was.

Amanda Douridas (04:14):
So what's been happening since then?

Jim Jasinski (04:17):
To evaluate the damage during the different stages of corn development, we would harvest the entire plants by cutting them at the soil line and then splitting them lengthwise from the lower stem up to the tassel to document the number of stock cavities and caterpillars, which would roughly translate into the level of plant protection offered by the Bt trait compared to its non Bt isoline or conventional hybrid.
So since 1996, many Bt genes have been identified and placed into corn hybrids for control of not only caterpillar pests like European corn bore, but also corn earworm, fall army worm, Western beet cutworm and also corn root worm larvae, a whole different group of insects which are also major pests of corn. So some of the Bt introductions have worked well in controlling these key pests, some traits have slowly lost their efficacy over time due to increasing resistance, and some Bt traits have had area wide failures across regions of the north central states.

Amanda Douridas (05:16):
Thanks, Jim. Do you care to explain some of the examples about the failures? Was it just traits that didn't provide protection? What happened there?

Jim Jasinski (05:28):
Yeah, those were mostly the corn root worm traited field corn hybrids that over in Illinois and parts of Iowa, they had planted large acreages of certain hybrids with certain traits and even under rotation, the corn root worms overwhelmed the Bt and we had lots of lodging and lots of losses in those areas. And in Ohio, we really haven't seen that, we just don't have the acreage that I think that they have out west and thankfully we just haven't really had those failures here, but it's possible. But hopefully again, we won't see that.

Amanda Douridas (06:10):
All right. So can you share more about what our colleagues at OSU are working on in the area of IPM?

Jim Jasinski (06:17):
Sure. So we have many faculty here at Ohio State who are currently involved in Bt related projects. One example would be for the past five years, Ohio state has participated in an international effort, led by Dr. Galen Dively at the University of Maryland to evaluate core earworm resistance against several Bt events that are in sweet corn. And corn earworm is the major, key pest to manage in sweet corn during silking. It is often the pest that drives the spray schedule, so it's very important. Corn earworm has got a lot of common names, it's also called the cotton boll worm or the tomato fruit worm. And it could be exposed to large amounts of Bt pressure from various host crops, such as cotton and field corn all the way into the Southern states. So corn earworm does not over winter here in Ohio, and so this pest migrates in the state each year and it's transported on weather fronts from the Gulf states like Mississippi, Louisiana, and Texas.
So if the moths arrive in Ohio around the time sweet corn is beginning to silk, any Bt resistance that this pest developed in the south may show up and cause unexpected ear damage when these migratory moths are deposited across the Midwest, not just Ohio. So in general, our results would suggest that several Bt traits such as the Cry1Ab or the Cry2Ab2 and others found in commercial sweet corn hybrids are no longer highly effective at controlling corn earworm and are not recommended for use unless the grower intends to treat the Bt sweet corn with a timely insecticide application during silking just like a conventional sweet corn hybrid. As of the taping of this podcast, only attribute two type sweet corn hybrids, and they have this VIP or VIP3A gene, should be considered highly effective against corn earworm and most of the other caterpillar pests.

Amanda Douridas (08:18):
So do they have some effectiveness still, and that's why they can be paired with an insecticide or are they pretty much non effective?

Jim Jasinski (08:29):
When you compare them to control and untreated conventional hybrid, you see some levels of control, but it really depends on the earworm severity or infestation. If it's a light infestation, you see a greater separation between an untreated Bt and an untreated conventional, but under high pressure, they look just about the same. You can get upwards of 80 to 90% infestation of the ears, so there's really not a lot of separation there. So, they just have really lost their efficacy of many of the caterpillars, especially under the high pressure.

Amanda Douridas (09:11):
And is this something that's widely known among sweet corn growers or are you guys still working to get the word out?

Jim Jasinski (09:19):
Yeah, well we have meetings in the winter. We have reports that we write and we do other kinds of outreach events where we talk about this and try to publicize it. But I think it's fairly well known and it doesn't take many fields of Bt sweet corn that are infested with earworms to realize that it's just not working as good as it used to and you ask the question why? So yeah, I think we're doing a pretty good job on both the research and extension fronts talking about which of these Bt sweet corn hybrids is effective and which ones aren't. So hopefully growers are tuned into that channel and are getting that message.

Amanda Douridas (10:01):
Great. Yeah, that's a good point. They're not hard to miss, that's for sure. So where can folks learn more?

Jim Jasinski (10:10):
So if growers or other people are interested to learn more about the Bt hybrids or their current recommendations for either a field or a sweet corn, I would say just seek out the researchers and the extension educators in state at your land grant university who have been conducting these evaluation trials on transgenic crops, or have firsthand experience working with these crops. Likewise, you can search online for past reports posted by other land grant universities. I would just say, if you're going to look for information online, just make sure the website, the fact sheet, the bulletin, the journal article is a trusted non-biased source of information. There's lots of information out there and not all of it is 100% accurate.

Amanda Douridas (10:54):
Well, thanks for your time, Jim, and your dedication to working in IPM.

Jim Jasinski (11:01):
Well, thanks, Amanda. I really appreciate chatting with you about this.

Speaker 1 (11:08):
Thanks for joining us to celebrate the 50th anniversary of integrated pest management. Check the show notes for resources mentioned in this podcast and be sure to subscribe so you don't miss any future episodes.