Pest Central

University of Nebraska #IPM50

August 24, 2022 Erin Season 1 Episode 7
Pest Central
University of Nebraska #IPM50
Show Notes Transcript

Additional resources:
http://www.cropwatch.unl.edu 

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

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.

Bob Wright (00:57):
Happy 50th anniversary of IPM from the University of Nebraska.

Anthony Hanson (01:02):
Happy 50th anniversary IPM from the University of Minnesota. Well, welcome everyone. I'm Anthony Hanson, an extension educator in integrated pest management from the University of Minnesota. And today we'll be talking with Dr. Bob Wright from the University of Nebraska Lincoln. Now, today we're going to talk a little bit more about a little bit of the history side of integrated pest management. And I thought this would be a good opportunity for Bob to talk about kind of one of the seminal papers that came out in about 1959. So welcome here, Bob, if you want to introduce yourself a little bit more.

Bob Wright (01:36):
Yes. I'm Bob Wright, an entomologist and extension IPM coordinator at University of Nebraska. Work primarily on field crop insect pest management.

Anthony Hanson (01:45):
All thanks, Bob. So the paper that we're talking about is kind of getting into this idea of, we talk about IPM or integrated pest management, a lot of questions come up. Where does this term integrated come from? Or what does it mean? And in this case, there's one paper that kind of got the term started a little bit. It's the integration of chemical and biological control of the spotted alfalfa aphid, the integrated control concept. So this is one that I know you were excited about talking about just in terms of what this meant for the field of IPM, both just for the history, but then also spotted alfalfa aphid, too. So you want to talk a little bit about why this is important to the IPM concept?

Bob Wright (02:29):
Well, if you've taken a course in IPM, you've probably either heard this paper referred to or the concepts. And a couple of important ideas came out in this paper. The most important was they introduced the concept of the economic injury level and economic threshold, which we still talk about in IPM. And the economic entry level is a simple way to talk about it is if you have an insect damaging a crop, and if you treat it with an insecticide to prevent damage, and you could save $10 an acre, but the treatment costs were $20 an acre, you would lose money. So the idea is that we need to scout and document the level of insects and injury and have information about whether it would pay to treat basically. And so the first concept is economic injury level is the big break even point. And then also economic threshold.
We need to back away a little bit and have a lower level for the economic threshold, so that you have time to implement an action and control the insect before it exceeds the economic injury level. And those ideas were first introduced in this paper. Interestingly, the [Sternidal 00:04:00] paper never described how to calculate an economic injury level or economic threshold. And it was almost 10 years later before that was actually done. And then as you mentioned, they promoted the concept of integrated control, which later got changed into integrated pest management. And they were looking to integrate biological and chemical control in response to the introduction of the spotted alfalfa aphid in California.

Anthony Hanson (04:33):
So Bob, one thing that was happening, I remember reading about this too, is with spotted alfalfa aphid, they were relying primarily on their insecticides and what was happening with the biological control in that case?

Bob Wright (04:47):
Well, they were using broad spectrum insecticides in those days, such as organophosphate and organochlorine insecticides, which kill off a lot of natural enemies. And prior to the introduction of the spotted alfalfa aphid, a lot of the work in California was trying to develop biological controls for the existing alfalfa insects, which were primarily caterpillars and other aphids, such as other aphids. And they were using conservation of biological control agents, strip harvest to control to conserve the natural enemies, even using early products of Bacillus thuringiensis were commercialized at that time.
Typically, when we have an invasive insect, until we do the basic biological research to develop an IPM program, the only option for an emergency control is an insecticide. And unfortunately the insecticides they were using at that time, the organophosphates and organochlorines ended up having residues in alfalfa, which was used in dairy production. Then we had high levels of insecticide residues in milk, as well as worker safety issues using these highly toxic insecticides. So there was a lot of need to develop a way to reduce insecticide use and still provide for economical production of alfalfa.

Anthony Hanson (06:24):
And I feel like on the insecticide front, this is one of the topics that we talk about a lot, even in the current day, where if we over rely on our insecticides, if we lose our biological control, that's often an added cost that sometimes causes more issues for us down the line when it comes to farming. And that's something that we see with alfalfa today, whether it's alfalfa weevil, potato leafhopper. This concept kind of comes into play pretty often where those two are very intertwined. It seems like.

Bob Wright (06:53):
And the other issue that they didn't run into in California, but we run into nowadays is when we rely primarily on insecticides, we may come up with insecticide resistance issues as well.

Anthony Hanson (07:07):
So Bob, how about the current day for IPM? We talk about this integrated control concept morphed into integrated pest management. So for the current day, how is this interaction working in our current IPM systems for a variety of crops?

Bob Wright (07:26):
Well, we continue to have new insects that get imported to the US. And when they first are introduced to an area, oftentimes they're introduced without their naturally occurring biological controls and do very well. And until we have time to do the research to develop biological controls and other integrated pest management practices, oftentimes the first thing growers respond to or the only choice they have is to use insecticides. In some cases, we have more selective insecticides than we did in 1950s, but still a lot of times we're using insecticides that suppress biological control and are not a sustainable way to control insects.

Anthony Hanson (08:18):
And Bob, I think that's a good segue into a future episode we'll be having here looking at soybean aphid as a good example of a invasive species where we had to develop an IPM program for. But in the meantime, are there any other resources you would want people listening to know about for specifically IPM resources from Nebraska?

Bob Wright (08:42):
Well, probably the best site is our cropwatch.unl.edu website that has information on entomology, weed science, and plant pathology issues for crops in Nebraska.

Anthony Hanson (08:57):
All thanks, Bob. And this was an interview with Dr. Bob Wright from the university of Nebraska. And I'm Anthony Hanson, extension educator from University of Minnesota. Thank you.

Speaker 1 (09:12):
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.