 All right, welcome to the NDSU Extension High Tunnel Webinar Series, so this is our April seminar. Jan Knodl is going to be presenting on spider mites in high tunnel crops, and she's actually writing an extension publication on this topic, so this is really fresh for her. But Dr. Jan Knodl is our NDSU Extension Entomologist, and she was recently promoted to full professor. So congratulations on that, Jan. Thank you. Now Jan's primary responsibilities include insect pests of field crops, but she also covers horticultural crops, and in fact we are co-advising a PhD student that is studying spotted winged drosophila, and we're also working on pollinator research. So Jan's program is very broad, but we're so happy to have her joining us today because spider mites is a very important pest in high tunnel crops. All right, thank you Jan. I'm just going to mute my microphone, and I'll let you take it away. Okay. Can you hear me okay? Yes. Okay, good. So, well thank you for the invitation to speak to you today, and I'm probably going to be speaking on probably the most challenging pests to control in high tunnel crops. And I've worked with it in field crops, as Esther mentioned, probably my main priority is working in field crops, and we've had spider mite infestations in soybeans and field corn. So I'm very familiar with the two-spotted spider mite at least. So prior to coming to Indie issue, I did work at the Beltsville USDA greenhouses on the leaf miner of chrysanthemums. So we'll get started with the two-spotted spider mite, and this is probably the most common one that you're going to see in the high tunnels. You can see this with your eye, even though it is very tiny, and you can identify it by the two dark spots on the back, sort of on the side of the abdomen there. They're generally found on the undersides of the leaf, but you can find them crawling around any time of the day on the upper surface anywhere in the plant. The life-spite of the two-spotted spider mite has an egg and then goes through the larval stage, which most mites are closely related to spiders, so they have eight legs compared to insects with six legs. But in some of the immature stages, they only have six legs, which you can see in the larvae life-stage. And then it goes through a protonim stage, dudonimp, and then the adult. And the thing about spider mites is they can get into a lot of different plants from trees, ornamentals to our field crops, so they're very common and passed on many different plants. In general here in North Dakota, they overwinter as eggs, either in the soil or on the vegetation. Development of the whole life-cycle is relatively short. It depends on the temperature. They can take as little as five days to go through their whole life-cycle, or as long as 19 days. And in general they crawl, they don't have wings like insects, but they crawl and then they spin strands of silk, that's where they get the name spider. And they use this, they'll crawl up to the tops of the plants, and then the wind will blow, or in the case of a high tunnel, you'll have the fans blowing through the high tunnel, and they'll move from plant to plant by these silk strands. Since they are so small, it's difficult to look for them. So oftentimes we recommend growers to look for the damage symptoms, and the feeding that a mite does is kind of different from other types of piercing, sucking insects like aphids that feed on the floam of plants or their plant juices. But the spider mite has a very needle-like mouth part, and they inject it into an individual plant cell, and then they'll extract the entire contents of that plant cell, including the green chlorophyll that gives the plant that green color. And as a result, you end up with these, it looks like little stipples on the leaves, and eventually those will coalesce and you'll get patches of yellowing in the leaf. So this is a good indication that you have spider mites and you should turn the leaf over to look for mites and webbing. And then here's a close-up of what the webbing looks like, and in 2012 we had a drought year, and spider mites can do a much higher populations during drought and dry weather. You can see the webbing on the flower as well. And they also can get attached to you when the workers are moving around in the high tunnel. They can actually be moving spider mites around and not know it. So we know that drought favors mite outbreaks, and in the high tunnels we have kind of extremes of temperature. It can get hotter than the outside, and then in the evenings it can actually get cooler than the outside. So if we have a dry summer, which it is forecast for a drought in North Dakota this upcoming year, spider mites may become a worse pest problem. And what they're doing is many of the grasses that they feed on, maybe outside of the high tunnel, are starting to deteriorate and die because it's so dry. And then they move looking around for new hosts with with better food quality and nutrition. Another reason mites do very well in the dry conditions is because fungal diseases that normally attack and infest the mites are lower when we have dry conditions. And the diseases are generally favored by cooler temperatures and high humidity. And also because of the reproduction cycle being so short and temperature dependent, we have a much higher reproductive rate when it's drought conditions with the hot high temperatures. So we already kind of went over the feeding and how they feed on individual plant cells, but you may see stippling or white spots and as it progress and it gets worse, you'll see leaf yellowing and bronzing, and then eventually you may see leaf drop and hopefully you won't let it get to this point. But this would be a severe infestation and they generally say if you're seeing the webbing from mites, it's already a high level of infestation. So you try to avoid getting to the point where you see the webbing and casing and the whole flower or the leaf because that's indication that it's already past the economic damage level. Feeding generally starts down towards the bottom of the plant and then moves upward. And this is true on just other mites species as well. So a good place to start to scout towards the bottom of the bottom leaves. And this does impact your yield. Sprater mites can impact yield all the way up through maturity. So they reduce the photosynthetic ability and water loss goes up. And as a result, you can get reduced fruit set. So there is some other mites that have been reported in high tunnels. And there's the tomato russet mite. And I should have pointed out the family for the two spotted, but this is a different family area Friday. And most of us are already familiar with this group. If you've seen gulls on some of the trees like the maples, those are ery-ified mites as well that cause those gulls. But the tomato russet mite feeds specifically on plants in the Solomaceous family. So our tomatoes and eggplants. They're very, very tiny. As you can see in the picture, it's difficult to get a good picture of them. They're less than 1.1 millimeters. So you can see them, but it's very difficult to see them. You're going to probably need to invest in a 20x hand lens. And then we use a microscope to confirm that they're present on a plant. So another important thing when it comes to control, if you do have the tomato russet mite, the controls that you use for the two spotted mites may or may not be effective on this mite. So you need to be aware of that. We'll talk a little more about chemical control later. But here's what some of the damage looks like. They cause desiccation of leaves and russeting in the fruit, a bronzing on the stem. And you can see some of the darkening here on the stem, a bronzing of the leaf, dead tissue. Now when you go to look for them, you don't want to look at this dead one. They're probably off that. You want to go up and find the next green leaf or partially green leaf and look for them there. They're kind of difficult to find. So we do use the symptoms rather than looking for the mites and look for the bronzing. This is a severe infestation here on this tomato. You can see how it's just bronze. A lot of times people mistaken this for herbicide injury or disease. And one of the other mites, this one's less common and we probably will not see it here in North Dakota. But there's also another mite that's been recorded on vegetables and leafy greens that we might grow in high tunnels. And that's the broad mite. And you'll notice again, it's in a different family, Tarso nemidae. And it's very tiny, just like the other mite microscopic. So you're going to need that 20x ham as our microscope again. You can see the scanning electron micrograph here of the mite. This one's a little more oval where the tomato russet mite is a little more long. And some people describe that one as cone shaped. But they vary in color. They're kind of clear or clear colored when they first hatch. And then once they feed, they can get more brown or reddish colored. And one thing about the eggs, if you do see any eggs under the microscope, they're very characteristic and you can use this for identification of broad mites. They have these little tubercles on the top of the egg. And that's unique to this particular species. If you do see this, you can use that for identification. And some people kind of refer to these tubercles as little jewels on top of the egg. So you can also see this mite in high tunnels, they like the lower temperatures compared to like a two spotted mite that likes it hot and dry. And these also like the higher humidity. So they have a little different niche. The damage is kind of similar to the russet mite, but these mites inject a salva, a toxic salva into the plant. And this causes browning and blackening of the new growth. And this arrow here is pointing to one of the mites. Just see it as a white spot. But as a result, we get distortion of the foliage twisting curling. And it also causes some hardening of the tissue and cupping of young leaves. And this one can be mistaken for viruses or herbicide damage as well. Well, we want to use IPM whenever we talk about management of insect pests. And one of the keys to IPM or integrated pest management is pest identification and monitoring. And in the high tunnels, we really probably don't use thresholds or predictive models, but those are some other key elements of IPM. So today I'll be talking about our different strategies which are over on the right side here. And we'll start off with chemical control. I usually do that last, but I thought I'd do it first for a change. So scouting, number one principle in IPM, when you're out there scouting, we need to know how to identify our pest and the good insects out there. There's many predacious mites, which are good insects eating our plant feeding mite species. So we'll go into a little more detail on the beneficials later. But for mites, because they have such a fast reproductive rate, we recommend you get out, well, we prefer twice a week to look for them, but at least weekly, at a minimum. And again, they're so difficult to see. Now look for that speckling, the damage symptoms, instead of, you know, the mites, but you can also the two spot, it's easy to see, but some of the others like the russet mite and the rod mite, they're down, sometimes in buds and in the joints, some where the leaves and stuff come together. So they're very difficult to see. And in the field crops, we've used this white sheet of paper method, which would be easy to use in your high tunnels as well. We just put a white piece of paper on a clipboard. And then you put that underneath the plant and then tap on the plant vigorously to dislodge the mites from the plant. And then you'll see them crawling around as little dots on the white sheet of paper. And then you can use your hand lens to see if it's the two spotted mites or microscope probably to see if it's one of the other species. We don't have traps available for mites. Although they could crawl onto some of the yellow sticky traps that we use for trapping other pests like white flies and aphids and sweet spotted winged or safflower. So you may see a few on there, but in general, they're going to stick to the plant and the undersides of the leaves. And I do have a video on scouting for spider mites and soybeans. If you want to watch that, you don't have to write that link down, you can just go and Google NDSU Extension YouTube and scouting for spider mites and soybean. It'll pop up. But I do demonstrate that tapping method on the white sheet of paper. For chemical guidelines, spider mites, especially because they're on the lower leaves and the bottom of the plant and the underside, make sure you use enough volume coverage is critical for effective control. And if you're having favorable environmental conditions for mites, the drought, or you already have high populations and you caught it late, you know, use that higher labeled rate. And then we do have pro-rethroid insecticides registered for control of mite. However, most of them will flare mite populations. There's only one active ingredient bifenthrin that is effective for control of spider mites. So we have to be very careful with spider mites and what we spray because they can easily develop insecticide resistance. We'll talk about that. But once you spray, you'll want to go back and re-scout to see how well your insecticide or your miticide did. Most insecticides will not control the mite eggs. They do not. So those eggs will be hatching and you will have to do a second spray. And then you'll need to rotate your modes of action. So to use a different spray, like organophosphate or miticide, if you sprayed with bifenthrin you're first. So you do not use the same mode of action twice. And this is more from soybeans, but it's a good demonstration. It shows you from an airplane. Of course, this one apply, but the same type of thing can apply to when we're going over and spraying. It's going to mainly, most of the deposits, spray deposits go in the top part of the plant. Only 30% reach the lower leaves. Then if we look at the upper surface, 62% landed in the upper surface, 38% in the lower surface. And if we look at the distal inner versus outer leaf, most of it was in the outer leaf. So you can see how the mites are cryptic, and they're hard to see. They're on the underside of the leaf. And it's difficult to get insecticides to reach them and do a good job with control. So sometimes we become too dependent on our insecticides. And we misuse our insecticides, we use the same one repeatedly for the same pass. And as a result, this can lead to insecticide resistance. And furthermore, you might be dealing with multiple species of mites. And it's important to realize that some of the miticides and insecticides are only effective against certain species of mites. So pesticide resistance is common in a lot of insects, and there's over 500 insects worldwide that have insecticide resistance. And we're seeing cross resistance becoming more prevalent in insect past species. And this means when you're using insecticide, make sure you're switching. If they're resistant to one, these are all parythrides on the side. If you're switching from like warrior to another parythrite, well, if they're resistant to warrior, they're resistant to all parythrides. So make sure you know your different families and modes of action of different insecticides, so you don't get resistance. And cross resistance is when one insecticide confers resistance to other insecticides because it's the same mode of action or mechanism. So how does it develop? Well, we go out and we spray and there's usually just a few survivors that may be tolerant or resistant have actual genetic resistance. Sometimes it's just a physiological resistance where they're able to detoxify the insecticide. But anyway, we continue to spray and we use the same insecticide. So eventually, we end up with a growing population of resistance. And then finally, we end up with a population that's almost entirely resistance. And most likely at this stage, it's probably in the genes. And we end up with a insect that has a hard shell, no matter what we throw at it, is able to survive. And it's the one that's going to be out there as the main source of genetics for breeding. So we all too often, you know, before we know it, we end up with insecticide or made of site resistance. And the pesticides become ineffective. And then it's necessary to switch to modes of action. And then this could repeat itself with the other mode of action. So that's why it's so critical that we can serve the tools that we have. So here's some of the insecticides, miticides that are registered in high tunnels. The first two brigade and Danitol are both three a mode of action, which is a parry fright insecticide. And the Iraq, you can go to the Iraq website, just type in insecticide resistant action committee, or irant, and you will find a complete website that lists all the insecticides available, and their modes of action. And you can see then here, we got some of the lower ones deal all the way down to acrimates. These are all miticides. And miticides are much more expensive than are like our parry fright insecticides. So and you can see this here is two spotted spider mite, and then broad bite, and then here's tomato russet mite. So you can see there's a few things that will control all of them. But if you have russet mite, you know, you don't have as big of a selection of insecticide tools to choose from. So and these are what is registered different crops. And well, I guess we can ask questions about that later. We have some. And when you're out there sprayed, remember that insecticides are like a windshield when you're driving down the road to everything else out there, including our beneficial insects, and not to mention our pollinators. So here's some of the botanical insecticides that you could use in high tunnels. You really need to read the late and understand the labels. There's so many different labels and trade names out there. I didn't list like which crops were registered because there's so much variation depending on the label and whatever you have. But these are the ones that had mites on the label and most of them do not list. They'll just say mites. So I wasn't sure if it included broad mite and russet mite for some of these. But one thing that would probably control all the mites is these oil sprays because they suffocate, they encase the whole mite and may suffocate it to death. However, there's been some research that shows the predatory mites are able to, they have longer legs and they can climb out of these oils and survive. So that's a benefit for using this horticulture oil. Then there's safer insecticidal salt that you can use. But again, some of these botanicals you're going to need to spray more than once a week. Most of the synthetic pesticides that I showed you in the earlier table, you'd be able to get by with spraying at a weekly interval. But these botanicals are broken down easier by the sunlight and temperature. So you're going to need to spray more frequently if you're going to use these. And then there's the parietrum from the excret of the chrysanthemum flower, peganic, is fairly good against mites. And then someone emailed me and asked me about sulfur. And yes, elemental sulfur is effective against the plant feeding mite species. However, it's highly toxic to the predatory mites. And also you have to be careful because a lot of plants are phytotoxic to sulfur, especially if it's hot. So you'd have to do a test, see, you know, whatever you're going to be spraying it on. And I did find off the high tunnel.org site, some research that's been done with entopathogens. Bavaria bossiana is a fungal disease that attacks insects. And they tested two different strains against mites, the natural L strain, which is the ATCC strain of Bavaria, and then the Botanical Guard ES strain GHA for control spider mites and high towels. And they did this on strawberries and cucumbers. And and they didn't wait till they saw high populations of mites, they sprayed as soon as they started observing them infesting the plants. So and you can see, see, I can't get my my pointer to work, but the green line on the graphs are the control or untreated. And then the green line is ATCC strain. And then GHA is the reddish line. The ATCC is the blue line. So you can see it worked fairly well in both the strawberries. I mean, it's slower acting. Most of these bio insecticides are a little slower acting and control, you won't get that rap and knock down that you see in synthetic insecticides and miticides. But you can see it did decrease the my population. And in general, they felt that the ATCC worked a little better earlier in the year when the temperatures were cooler. And then they felt that the GHA worked a little bit better later in the year, August, when the temperatures were a little bit higher in the tunnels. And you can find the whole report on that website. And here's what they saw in yield differences. They got good, good control. They didn't separate it out by treatment. But in general, using Bavaria, they saw a increase in the cucumbers 35% in 2009 and 25% in 2010 over the untreated or the control. So that looks some fairly promising. But there has to be a lot more work done on these types of biopesticides. Well, now I talk a little bit about some of the other strategies, cultural host plant resistance and biological control, cultural control prevention. You know, we want to cool these tunnels down to make them more unfavorable for might reproduction. We'll have fans going to train reduce how hot it is during the day. And then when it's dry, we mentioned, you know, how well the mites do, well, dust, mites can do well, they like dusty conditions. So maybe use a mulch between the rows, such as a ryegrass or some sort of mulch to keep the dust down and off the plants. And then before you bring plants in, I'm not sure if you're doing transplants or if you're planting from seed, but make sure you're not bringing past already into the greenhouse when you're introducing new plants. And avoid wearing yellow clothing. We use yellow as a attractive trap for capturing many of the costs found in high tunnels. And then sanitation, when you do get a very heavily infested plant with mites, you know, go ahead, just pull that one out, get rid of it. So you don't, it doesn't spread from there. Oftentimes in mites, you will have hot spots. It's pretty common. And then because they're on the lower leaves, I saw some research where they suggested pruning the lower leaves, and then discarding them and getting rid of them would would help reduce the infestation. However, you have to be careful, you're not taking too many leaves off. So it's not going affect the plant health. And then weeds, if you keep the weeds mowed around the outside of the tunnel, they harbor a lot of past and two spotted spider mites, as you know, gets on hundreds of different plants. So keeping the area weed free and mowed outside the tunnel will help prevent the movement into the tunnel. And then there's the suggestion of using screens can be fitted for the tunnels as well. To try and exclude them. And then crop rotation. This is suddenly used for a long time. You know, don't in gardens, we, we don't plant the tomatoes in the same location year after year. Try to move it around. And then I watched the video last night where they had developed this high tunnel was on wheels. And they actually moved it on this was kind of like a train track. And they had were able to move the high tunnel around between years. So it's kind of an interesting idea. And then host plant resistance, there hasn't been a lot of work done in this area. But take, you know, take notes, if you notice a variety, or cultivar that has less mites, you know, make a note of that. I did find some information on boa tomato had less mites than trust tomato when they grew them side by side. So there is differences between the cultivars and varieties out there. So make a note of that. And, you know, there's needs to be a lot more research on this area. And then finally, biological control can be very effective for spider mates. And it's also commercially available predators are. So it makes it easier for everyone to get on board with more sustainable approaches. So this is probably our number one predatory bite phytocelus persimilus. And this one is specific just to the two spotted spider mates. So it's highly dependent on it. It's a beautiful, reddish color and note how much longer the legs are. And that's because they run much faster than the two spotted mate. They're a predator. So they need to catch the two spotted mate. Kind of a pear shape, again, very tiny 0.5 millimeters long. And the imitators and males are a little bit smaller and lighter. Eggs are kind of a long color. And they prefer kind of moderate temperatures, the predators, and humidity 70 to 80 or some people, well, in North Dakota, we kind of consider that high, but they don't do well when it gets real hot, like in some of the high tunnels in the summer, they'll get up into the 90s. So that's not favorable for the this particular predatory might. And since they are dependent on the two spotted spider mate, if if that is not present, this will die out. And you'll have to reintroduce it. For the life cycle, it's just like the other plant feeding mites, it's a short life cycle. Depends on temperature can take, you know, at a higher temperature, only five days. At a low temperature at 59 is 25 days. They're fairly long lived as some adults up to a month. And there's more females than males. So this is something we look for when we're evaluating predators, we like to see more females because then you get more egg production, and better reproduction rate. The label 68 in their lifetime or two to three per day. And the population can increase 44 times in 17 days. So that's pretty good. They consume about five to 50 prey per day. And they're commercially available from a lot of different companies. And they are not recommended, though, as a preventative program, preventative is where you release something, maybe just at the beginning, when you see just a few mates, they don't do well, because they're so dependent on the two spotted spider mate, they don't feed on any other past present in the tunnel. So you may want to wait until that two spotted spider mate population has become somewhat established before you release them. And there's different release rates you'll really need to work with your company or your insectary supplier on what they recommend. They're all kind of have a different recommendation. However, I found the 1000 percent less per 10,000 square feet was a result from a Sarah study and high tunnels at Cornell University. So I felt that was a fairly good number to go with. And if you do have a heavy infestation, you know, remove the heaviest infested plants and get rid of them, then you may want to use a knockdown spray with maybe one of the bio pesticides to knock them down, and then wait 48 hours before you release the mites. But if you release them too late, the predatory mites will have a hard time catching up with the plant feeding mites that cause the damage. And then these are some of the other species that are available. And there's more I didn't I'm not listing all the predatory mites you can get from suppliers, but these are the ambicellus californicus and in the ambicellus tucumorus, they're two that are commercially available and fairly common. And these are more generalist feeders, which though so they'll feed on other things you might have in your high tunnel thrips, and aphids, and also the other mites, the russet and the broad mite. So that makes them, you know, maybe you want to do rather than just one predatory species, you know, consider doing two or three different species. So they're very tiny as well, what their first kind of a clear or white peach color, and then they turn brown or red. So and you can get them from different companies as well. They usually come with some sawdust or to keep them alive. And they're there, they like a little more hotter conditions as well, these predatory mites, they can take up to 90, but they like, I believe that's a typo, it's supposed to be 50 to 80 degrees Fahrenheit. And they can tolerate less humidity as well, down to 60. Whereas the predatory mite of the two spotted, that one likes the higher humidity. So they have a little bit different and this one's better for perennative pest control. So you can release it a little bit earlier than you would the other mite predator. Now it might take multiple applications. And this 1000 mite per 4500 square foot was that Sierra study from Cornell. And they had success some in their tomatoes and cucumbers and high tunnel with with these mites that Cornell University where they did the study. So here's the this is from the Cornell University. And they looked at the effect of the predatory bites on the controls of two spotted and on heated high tunnels and greenhouses. And the rating here zero, you'll see the different numbers. And the rating zero means it didn't work. It failed. Three was the pest was controlled. Five, the pest was eradicated. So you can see what they have ratings for the different predatory mites there. And you can see some were highly successful. You know, most of them they had got good control with the predatory species. So it's something not to consider. And if you do try out the biological controls, this is probably the top five reasons why they don't work is maybe you introduce them too late. And they just can't catch up with the night species feeding on your cucumbers and tomatoes, or you release too few of the beneficial predatory mites. And the two spotted spider mite was too high, or you had poor environmental conditions, why temperature swings and both temperature and humidity. And sometimes those predators just can't tolerate that. And then also, you got to be familiar with your suppliers and make sure you talk to them, know when they're shipping things out, usually they have a particular day they would need your order in to get it shipped to you quickly within a few days. If you miss that time, you know, it might be the next week before you can get your shipment. So make sure you talk with your supplier and you're aware of their shipping requirements. And also, you know, check out the quality of their natural enemies, you know, is it supposed to have 500 emerging from this container, you know, do some checking to make sure they have good reliability on their natural enemies. And I did run across some papers that actually looked at that from the different companies. And then some crops can tolerate some past some. So maybe you may have a resistant variety. No, maybe there's not enough mites on them to, you know, have predatory mites get established. And here's some of the insectry suppliers I listed some of them before, but there's a lot of them you can go to the website where there's a whole list of all the suppliers of beneficial organisms in North America. And there's like hundreds. So find somebody who can work with you and help you educate you as well on the use of these beneficials. So but there is a lot of benefits to using biological controls. You don't have to be worried about the synthetic pesticides and some of the toxicity issues. If you have workers and you're tall, there's no pre harvest in our full or re entry intervals to be concerned about not going to get any phyto toxic reaction or burn on the plants. And it's actually they've done studies that show you're actually a little takes a little time to release these predators. It's not as much as, you know, spraying, mixing up application, cleaning up and all that. So it fits both the needs of conventional and organic growers. And another thing is, you know, we got to be concerned about our pollinators. There's more than just the bees out there doing pollinated pollination, there's surfeit flies, soldier beetles. And we recommend that you don't spray blooming plants, try to, you know, use least toxic pesticides, if you do need to spray during bloom, but we really don't want sprays to go on during bloom. And then use short residual insecticides and mostly beekeepers tell you, you know, the evening is the best time to spray when the temperatures are quite, you know, below 55. There's been a recent paper that just came out in environmental entomology, leach and asic. And this is at Michigan State. And they did bee or pollinator observations in 10 minutes, periods, in raspberry and bloom and hot high tunnels. And they actually found here's a dark bar is the high tunnel and they found significantly lower honeybee populations. However, they didn't see that with the mumble bees, but they were releasing bumble bees into the high tunnels for pollination. And then they found significantly lower wild bees as well in the high tunnels. So it looks like the honeybees and the wild bees do not like to go into high tunnels. So that's an interesting observation that I wasn't aware of, that the tunnel actually seems to inhibit some of the bees. Yeah. Yeah, this is Esther, I think in fact, the tunnel does disorient the honeybees and the wild bees, but not the bumble bees. Yeah, that's what they were also found in this study. So when that's all I had for you today, I'll be happy to take any questions. It looks like I'm on time. I didn't want to go too much over 45 minutes. Oh, Jan, it was just perfect. Okay. And we do have questions in the chat box. So I know, I know when we're dealing with spruce trees and spider mites, we talk about syringing. Does syringing work for high tunnel vegetable crops? So we're using a spray of water. Oh, okay. I guess that can can work. I but you need a high pressure, you know, sometimes you have to be careful because it can damage your plants. So you can use a high pressure to wash mites off and drown them. In fact, I've seen that in soybean fields. Usually before they have canopy closer closure, when they're smaller, it's easier to do that once the plant gets larger and has more leaves and canopy cover, then it gets a little more difficult, but because the mites can hide, you know, down in the soil even. So it takes a usually when it's been effective, it takes both wind and high pressure to get them off. Okay. So question on resistance. Can insecticidal or miticide resistance occur in a single growing season? I, it, yes, it could. And down in Texas, I know where they have much higher pressures from mites. They have different species of mites as well. But they could occur. mites are very quick to adapt. And their life cycle can be as short as five days. So it could happen. It's probably not. It's more likely it would happen over several years. But then, you know, just in one year. And then somebody wanted to know where they could access the the list of insecticides and miticides. So I think you that is some. Let's see. I got that off. I'm assuming you'll be posting the webinar. Yes. I kind of compiled it from two different sources. One was Kentucky, had some references on online for high tunnels. And I think I got some from Purdue University as well. So I kind of combined it from a couple different sources that had some publication and newsletters. Okay. No, would you mind if we could just get that table and then we could provide just the table on the website too? And I'll be probably putting something similar in my fact sheet. Excellent. And then we have a question on diatomaceous earth is as what is your opinion on using diatomaceous earth as an initial control solution? Yes, that will work against some. In fact, I read one paper where they were combining diatomaceous earth, which is little crystals that get in come into contact with diatomaceous earth. So it's little crystals of and they get attached to the insect body as they crawl on the ground. And that causes the cuticle to have holes in it. And it also gets caught in their, well, their spiracles or their noses. And then causes breathing problem or respiratory problems. So yeah, that can work against mates and other insects that you might have. And one research paper I read combined using diatomaceous earth with that Bavaria. And they felt that that would increase the fungal antipathogen getting into the body of the insect, but they didn't find that relationship. And then of course, we'd want to remind people that if they are applying diatomaceous earth, it's good to wear a mask while you're doing so because you don't want to be reading it. Breathe in those particles. No, it could do the same to us, cause us to have some respiratory problems or very small little particles that can get in. And then I had another question emailed to me if we sprayed a lot of one chemical last season, are the mites that carry over the winter likely to be resistant to those chemicals? It's hard to say where if you were seeing problems with controlling the mites, you may have resistance. If you were getting good control, and I would say good control is like 80% for mites, your mites are so difficult to control, you'll never get close to 100%. So we consider 80% good control and we're talking about mites. So if you did start, if you were seeing poor control last year, and you know, it wasn't due to your application technique, poor coverage, or you were spraying during the heat of the day, I didn't mention it, but many insecticides break down fast, like the paris, right? Insecticides by Fenthrin break down fast during the heat of the day. Can you ask me? We don't recommend spraying when it's above 90. No way, tell it's cooler in the evenings. You'll get better residual. Whoops. Sorry, I, there we go. Whoops, Jan, I, I think I screwed up the mute button here. So I need to unmute everybody. I was trying, I was trying to unmute our participants so they could ask questions. So I will forward that information. And if you have any questions, you can. Okay, so if anybody has questions, I have unmuted your microphone. So please feel free to jump in and ask Jan some questions here. I see there's one on sulfur burners. Oh, I'm not really familiar with sulfur burners. I'm assuming that's like a fogger. Yes. Yes. I'm not sure how well fogger would work for nights. It would be something you'd have to try. Yes, and I think we use that more for powdery mildew. Has anybody else had good control with using the sulfur burners? See any, any questions out there? No, please feel free to type them in the chat box or use your microphone and ask the questions. Well, Jan, I wanted to ask you how common the tomato russet might is. I mean, are we starting to see that more in North Dakota? I think I've seen it. Yeah, I think I have to. In fact, I think I missed a sample that came into the diagnostic lab last year. And I wasn't as familiar with that darkening symptoms. So but I don't know what's the tomato russet might and the broad might are not as common as the two spotted might. That's by far most common species, the two spotted might. But I have seen that russeting right on the tomato fruit just a couple of times. So I think I think it must be here. Yes. Yeah, they're all all these three species I talked about are cosmopolitan in their distribution. So they're everywhere. If the if the, you know, growing conditions are right and they have the right host plants. And we could likely if you're getting transplants from, you know, the South, I could likely bring it up. I don't know how we'll survive here. Alright, I'll check the chat chat box. Alright, any any questions for Jan? This is your this is your opportunity. No, let's see. Well, Jan, I want to thank you for presenting. I mean, this was very informative. And this is a very important pest for us, particularly with the close proximity that some high tunnels are to soybean fields and, and to other fields. But I also wanted to share something. So, Jan, would you mind taking down your PowerPoint? And I'm going to share an announcement for our high tunnel conference. Alright, so I am just going to bring up my PowerPoint here and and share that with you. Okay, there's my I lost my mouse there for a while. Okay, so hopefully you can see this. I'll go to slide show. So we are having our NDSU high tunnel workshop this month on Saturday, April 28 from nine to five a.m. And this will be on our campus in our big lecture hall 114. Now we are offering a price break for the workshop. If you register by April 20, it's $50. And then after that registration will increase to $100. So if you register between April 21 and the 26, it's 100. If you you can register at the door and it will also be 100. And we would need to check at that time we can't take credit cards. The reason that it becomes so much higher is that we then have to deal with buying in special food. So we will be providing will be providing lunch and snacks during this event, but it gets a lot higher if we don't have advanced notice and it makes it really hard to plan for that. So we do prefer if people can register before April 20. I'll be sending out a link today. And then this is this is the agenda. So we're Harleen Haderman Valenti has actually organized this event. Harleen, if you like, you know, turn on your microphone. But she has organized a very nice event. We've got Dr. Lewis jet from West Virginia. Matthew Klein hands from the Ohio State University, and Sarah Brotch from the University of Minnesota, they'll be appearing via webinar tech technology. So we're going to be using zoom for those speakers. And then our in person speakers will be Dr. Haderman Valenti, Dr. Gordon Robinson, and then Tim Gainard, who I'm who I'm sure you probably met at the last conference, and he's going to be talking about vegetable cultivars. So any questions on our workshop. And we're hoping, hoping that you'll be able to tour our new high tunnel. So we're going to be constructing a high tunnel on campus this month. But Harleen, am I missing anything here? This is Drew up here in Williston. Thank you. Great seminar. How's the weather affecting your high construction? It has definitely slowed us down. But we are hopeful that this will get built before the 28th. So we've Harleen has got a great crew and they've got everything planned. As soon as we can get a couple warm days, they'll be in constructing this and, and they've got this down to a science. Well, good luck. Thank you, Drew. You can come down and help us. All right, if there are no questions, I want to thank Jan again for for joining us. And we will be posting the recording online so you can go and and listen to parts of this again, because I know that there was a lot of good information here. Right. Thank you very much. And everyone just stay warm. Thank you. You're welcome.