Text Transcript and Description of Visuals
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| Music Plays | Title card. Video title: Bin Management for Codling moth. Interviewee information: Brad Higbee, Director of Field R&D with TRECE Inc. |
| Welcome, this is Brad Higbee coming to talk to us now, with a focus on codling moth around bin piles. So Brad, can you introduce yourself and tell us a little bit more about your career and experience in codling moth? | Two speakers appear on screen in a split screen video call. |
| Sure, I got a bachelor’s degree in biology down at UC Irvine, and I thought I wanted to be a veterinarian. So I moved to Washington intending to go to veterinary school at WSU. But I was I was married, and had a kid. I needed to work, and I figured I would work for a year and I got a job with a guy by the name of Robert Fye. He was with USDA-ARS in Yakima, Washington there. He was working on a biological control project for pear psylla, and my first job with him was raising ladybugs. So my job was to figure out how to raise massive numbers of ladybugs, and we had about 12 or 15 species from all over the world, that had been found in pear orchards in other parts of the world feeding on psyllids. I went “wow, I had no idea that you could get paid to do fun stuff like this”. So, you know, I was fairly successful in raising up all these ladybugs and releasing them. However, it was very frustrating when we never found one of these ladybugs in a pear orchard and they didn’t really take hold. Although it turns out, one of them kind of became established in the landscape, feeding on aphids on trees. And that’s another story. Anyway, so I changed my whole idea. I said this entomology this is really fun. | Brad appears full screen. |
| I grew up in avocados and citrus. We lived on avocado and citrus farms. My grandfather was a manager of avocados and citrus, so I worked for him in the summers. And I was on this soft money grant with Dr. Fye for about seven years, one year at a time, through the Washington State Tree Fruit Research Association. Eventually the USDA opened a job that I was kind of groomed for, we’ll say, and I just started working my way up the ranks until about 1990. We got funding for this codling moth area project and they promoted me to the scientist level and kind of put me in charge of a couple of those projects. Then at the end of those projects–within a couple years, around 2001–I got an offer I couldn’t refuse from a very large almond a pistachio farming operation down in Bakersfield, California. So I moved down there in 2002. So I’ve been working in, basically the almond and pistachio and pomegranates industries, to some degree since then. | |
| Thank you. So area-wide project was in the 90’s. So that’s 30 years ago. We have fewer people who were in the industry 30 years ago. So can you review and tell us, what were the goals of your area wide codling moth project. | View switches back to split screen of Brad and the interviewer. |
| Well I guess the main goal was, mating disruption was a relatively new technology for codling moths, and it was slowly being adopted. But, you know, people just weren’t real sure about it. So this was a way to kind of showcase that as a viable IPM strategy in these relatively large projects. It actually kind of became both a scientific and sociological endeavor, where you get these contiguous farms with different growers to basically sign on and say “okay we’re going to cooperate, share information with each other, and help that help us guide our management strategies”. There were a number of these big area-wide projects. Two of them were in the Yakima area: Wapato and Yakima. I managed two of those, and there were of course many others in California, Oregon, and Washington. Then in our case, we had some other growers outside of these area wide projects that served as our, kind of, conventional comparison. So we…and when I say we, I had a whole team of people that were responsible for monitoring traps and reporting that data on a weekly basis. We examined fruit for damage at various times for the season and at harvest. Then we compared all this information between the area-wide sites using mating disruption and the conventional sites, which were not one big contiguous area–but they were located, you know, relatively close to the area-wide projects–and compared damage, trap data, and such between them. | Brad appears full screen. |
| So you have all these all companies working together and sharing information to do area-wide codling moth management, being compared with those that aren’t under that same program. So if you were going to sum up the take-home message from the area-wide project in just a couple take-homes or positive things that came from that, can you share those with us? | View switches back to split screen of Brad and the interviewer. |
| Well I mean, I think the number one thing we showed was that mating disruption was viable, both operationally and economically. We kick-started adoption of mating disruption, I think, to a large degree in Washington and other areas as well. That’d be the big thing. The other thing is, we showed that cooperation and being aware of information outside of your particular farm was valuable information and helped everybody in their approach to management. That would be number two. And number three is, we were actually able to reduce insecticide sprays based on the level of monitoring that we did. So that monitoring becomes the important piece of information when you’re trying to make a decision on making an insecticide cover spray, for instance. | Brad appears full screen. |
| Okay so you have unique experience from that time period in that, you did work on measuring and monitoring codling moth populations around bin piles. So that’s really what we want to drill down to and capture some of that information that you found out. So can you first just tell us what your efforts were? Just sort of describe what you did in that work. | View switches back to split screen of Brad and the interviewer. |
| Yes, this is going back in my memory. Fortunately, we published a paper, so I was able to review that quickly before our interview today. But there was this idea, and nobody really knew the extent or the impact of these harvest bins on introducing codling moth into an orchard that they’re brought into. So I looked at a few aspects of that. The first thing I wanted to find out was:” Okay is this the real thing?”. Do these overwintering codling moths actually get into these harvest bins. | Brad appears full screen. The title and author information of the mentioned paper appear above him: Higbee, B.S., Calkins, C.O., & Temple, C.A. (2001). Overwintering of codling moth (Lepidoptera: Tortricidae) larvae in apple harvest bins and subsequent moth emergence. Journal of Economic Entomology, 94(6), 1511-1517. |
| So we set up a little study where we had put wooden bins out in orchards where we had we had done a damage evaluation before and at harvest. So we just spread the bins out like they would normally be spread. It was about 30 days before harvest, and we had a few sites with wooden bins and a few sites with plastic bins and we knew what the infestation levels were in the fruit. | A wide outdoor shot shows stacked wooden fruit bins alongside stacked plastic fruit bins along a gravel road, with an orchard and distant hills visible in the background. |
| So we’ve got all these bins out there for a month before harvest. Half are empty, half are filled with fruit at harvest. We brought them into cold storage, and once the fruit was emptied out of the bins that were full of fruit, we started bringing them into the greenhouse. We covered them and looked at emergence of moths from these bins. So what we found was that there was about a 98 percent reduction in the moths that emerged from plastic bins. So we rarely found moths burrowing into plastic bins. But, believe it or not, some of them actually did. We did get some, and you could actually see them if you knew what to look for. They would actually use their mouth parts and, kind of, dig a little burrow and then form their hibernacula in the plastic. | Brad appears full screen. |
| Whereas, in the wood bins, much more common regardless of the level of infestation of the fruit at harvest. We found no difference in the number of moths that were in the empty bins versus the moths that emerged from bins that were full. | Close up photo of codling moth hibernacula on the surface of a wooden fruit bin. |
| So they weren’t full for very long, obviously, which suggests that they didn’t move right out of the apples and go into the wood. I think we also did a Good Fruit Grower article that had some nice pictures of these hibernacula formed in the wood bins. So then–okay, yes–we definitely have potential here for codling moth to overwinter in wooden bins. So then the next thing we did was, we got some bins together from, I believe, Fred Plath. We were working at Fred’s home. So we had three sites where we made stacks of bins. I think it was six by six by six. We paired these stacks and put temperature monitors. We basically looked at three positions: low, middle, and top level. | Brad appears full screen. |
| We inserted lab-reared moths into these different levels, and we just basically checked them every day. And as they emerged, we noted when and what level. My technician came up with this ingenious little way of sliding cages in there and pulling them out so we didn’t have to undo the whole stack of bins. | Close up photo of a codling moth emerging from a hibernacula on the surface of a wooden bin. |
| But anyway, one thing I wanted to check into was: “okay, could we cover these with plastic? And what effect would that have on these emerging moths?”. So we kind of looked at a couple different things. The first thing we did–before we actually started the experiment–we put traps on the edges of orchards that were near bin stacks. And, sure enough, we saw elevated counts in these traps on the border. And in about, you know, 50 feet or something, we could see this elevation on the edge, and then an attenuation of the trap captures as you moved into the orchard. So we go, “okay we we’ve got moths coming off”. So we decided to look at temperature differences and then see what covering… We did actually did both clear and black plastic. We just published on the clear plastic because that seemed to have the most impact on temperature within the bin stack as a whole. So what we found is that, the emergence from an uncovered stack of bins was very attenuated, very stretched out, and covered a long period of time. As you might suspect, the highest level was the warmest, the middle level was next, and the lowest level was the coolest over the course of this emergence. So you had emergence kind of beginning just after you would see a field peak, you know. In this case, it was May. Sometime in May, we hit our first peak. So the lower levels were last to come out, and we got emergence from this uncovered stacks of bins well into June. | Brad appears full screen. |
| So when we covered the bins with plastic, the upper levels particularly heated up. And the emergence of these moths was not quite as attenuated. It wasn’t over nearly as broad a period. But they started emerging, depending on the level, a week to a month before the moths in the uncovered stacks of bins emerged. And it was much more closely timed with the field populations and when they peaked, which we also looked at in parallel. | |
| So that was a very detailed experiment. Did you ever look at the effects of sanitizing the bins and how that may have affected moth populations? | View switches back to split screen of Brad and the interviewer. |
| Ah, interesting question. You know, it’s funny because that is the exact question that I asked Fred Plath after this experiment. It was a two-year experiment, and I said “So Fred, what do you think about some kind of treatment on these bins?”, and he looked at me and said “Brad, even if it just cost a dollar a bin, we’ve got millions of these things and I just don’t think it would be cost effective”. So that was then, now there might be more motivation to do something. | |
| So it was pretty clear from our work that plastic bins were superior in the sense that they did not harbor overwintering codling moth nearly as much as the wooden bins. | A wide outdoor shot shows stacked, white plastic fruit bins outside of an orchard. |
| Are there any other ways that you are successful at looking at controlling codling moth populations around bins? | View switches back to split screen of Brad and the interviewer. |
| Well the most the most straightforward approach is to monitor first, right? Every group of bins is not necessarily a problem. If there was very little or no damage in an orchard that those bins were used in the year prior, you may not have much of a threat, but you don’t know until you do some monitoring. | Brad appears full screen. |
| So the easiest way to do that is put some traps along the along the edge. I would not necessarily just do one trap, but a number of traps spread beyond the edges of the bin stack itself. | A close up shot shows a bright yellow codling moth trap suspended in the canopy of an apple tree. |
| Then maybe, you know, a few traps in the interior as it’s helpful to have a comparison. If you just have traps on the edge, and you catch high numbers, unless you have some traps on the interior that show you something different–in other words, lower numbers–you don’t have that gradient that kind of points to the bin. If they’re relatively equal, maybe that’s just your population in your orchard. So once you establish that, “yeah, it looks like these bins are throwing off some moths”, spraying an extra cover spray or two is the most straightforward thing to do in that area. Recalling that, I think Vince Jones did some work looking at movement of moths as they hit the edge of an orchard, and they don’t necessarily go straight in. They may kind of fan down the edge and maybe even go around the corner. So pick out a reasonable area to treat, and that’s where traps can help define that that area for you. Just do a little bit of extra spraying. | Brad appears full screen. |
| I will mention one other thing in terms of mitigating codling moth emergence from apple bins. Larry Lacey did work looking at entomopathogenic nematodes and treating bins in the warehouse with these nematodes that would go in and attack and kill the codling moth. I believe that was fairly successful. I suspect, as I recall it was the cost factor, at least, and there may have been some practical issues as to why that wasn’t adopted. But that’s something that may be worth revisiting. | |
| What would be your response when we hear our industry say, “Wow, plastic bins are superior but they cost so much extra.”? | View switches back to split screen of Brad and the interviewer. |
| Well that’s a valid point. I imagine they are several times as expensive per bin. I’m not up on the latest costs of wood versus plastic, but I understand that. But if you’re gonna have wood bins, and they’re coming from a packer, and you don’t know the history of where they’ve been, it would be worth your while to keep an eye on them. well you have these pictures from our good fruit grower article that kind of show you what it looks like you know it’s mostly a first generation I mean if you if you’re going to see something it’s you’re going to see the activity toward the tail end of your first generation flight that this is why uh you know your Brays are typically directed at the first generation and the peak and so these would come after when your residues are the most aged and least effective and so it might be worth another shot in that area | Brad appears full screen. |
| But if you’re gonna have wood bins, and they’re coming from a packer, and you don’t know the history of where they’ve been, it would be worth your while to keep an eye on them. | Close up image of a codling moth forming a hibernacula in a small hole on a wooden fruit bin. |
| You have these pictures from our Good Fruit Grower article that kind of show you what it looks like. It’s mostly a first generation. | Images appear one after another on screen. The first is a close up shot of two codling moth pupae inside of a wooden fruit bin. The second is a close up shot of a the silken codling moth hibernacula. |
| I mean, if you if you’re going to see something, you’re going to see the activity toward the tail end of your first generation flight. This is why your sprays are typically directed at the first generation and the peak. So these would come after, when your residues are the most aged and least effective. So it might be worth another shot in that area. | Brad appears full screen. |
| So we’re coming to a close now, and what are some of the key take-home messages for managing codling moth around bin piles? | View switches back to split screen of Brad and the interviewer. |
| Well, I think in terms of management, if you’ve got wooden harvest bins coming in and being stored, do some monitoring. Try to establish whether you think you have moths coming off of that stack of bins. And if you do, you may need to do a little extra insecticide treating in the area adjacent, and in the general vicinity of this storage pile. A stack of bins is much cooler at the bottom. Degree days are accumulated much more slowly at the bottom than at the top. So it’s typically going to lag behind field population. So you’ll have this delayed emergence, if you will, in the early part of the season. If they’ve been there the whole season, I think you can safely assume that, by the time harvest rolls around, the moths have emerged. I wouldn’t expect that any new inhabitants have taken up shop in these bins, so they should be fairly safe to spread out in the orchard. On the other hand, if you’re receiving these bins just prior to harvest, you want to try to wait as long as you can to avoid codling moth worms finding their way to the bins, forming their hibernacula, and pupating inside the wooden bin. So, the least amount of time prior to harvest that the wooden bins are in the orchard, the better. | As Brad states the three key take-home messages, text appears on screen highlighting them. |
| Music Plays | Credits for interview and video production roll. |
