 Welcome to the Spring Fever Garden Forums where we connect you, the gardener, with the experts at North Dakota State University. And my name is Tom Cobb. I'm an extension horticulturist in the Department of Plant Sciences. Tonight is the third of our four nights of forums. And our theme tonight is having a healthy environment. Let's get started. You know, it's a delicate balance between killing the harmful insects while also trying to protect the beneficial insects. And so here's a provide us with some advice is Dr. Jane Canoldo. Jane is the professor and extension entomologist at NDSU. For 23 years, she has provided statewide leadership for extension entomology. She is the director of NDSU at Dakota IPM, that is the integrated pest management program, as well as the NDSU crop and pest report. Her outreach and research efforts focus on insect pests and crops, as well as the pollinators bees and butterflies in crops and gardens. So, Jane, welcome to the forums. Hi. Good evening everyone. I usually talk about the good insects, but tonight I'll be talking about the bad insects that attack our flower gardens. So, and one of the things I always emphasize in my program is integrated pest management IPM. And I'm sure most of you've heard of it, but it's a sustainable approach to managing pests by combining biological, cultural, physical and chemical tools. You can see the IPM basic slack sheet there, it's more for agriculture crops, but if you're interested, you can download it from the NDSU publication website. So we have several different things that we use in our IPM toolbox. Pest identification is key, knowing whether it's a good insect or a bad insect, and then pest monitoring and knowing a little bit about its biology so you know when to go out and scout and how to look for it. And then we have economic thresholds and predictive bottles, but for flower gardening, we really don't use those very much it's more authentic thresholds because you may have a plant that's been in your family garden for a long time and maybe over 50 years and you want to preserve that plant no matter what. So, there's all the different strategies here that I mentioned earlier about IPM at the top is the more preventative ones and more environmentally friendly. And on the bottom is the more toxic strategies and the ones that we have to use with more intervention. So, the first step identification. There's, if you haven't had an anemology graduate level class, you know you may struggle a little bit with insect identification, but there's a lot of books out there that don't use taxonomic keys where you have to learn, you know, what some of the languages that we use and taxonomic keys that is quite difficult. And this these books use primarily pictures so it's much easier to identify insects you just compare the pictures. And there's quite a few websites as well popping up that you can use. And of course, you can always send a picture to me or the NDSU plant agnostic lab. I got 20 minutes I'm going, I just selected six insects, and I'll go through these six but there is a lot more. But these are six that I've been having trouble with myself in my garden. I'm sure we've all experienced aphids because they get on a lot of different plants. They can be all different colors of black, gray, green, pink, red. So they're kind of colorful. They're very small, about an eighth of an inch or smaller, and they're soft bodied and pear shaped. And we generally can tell it's an aphid by these balls or just tail pipes that produce protrude out the back end of the aphid. And you may say winged or wingless aphids, the wingless ones are mainly used for migration when they're moving around, or if the crop or the plant is overcrowded. They'll use wings and develop wings to move to an area that is less populated. So they do have rapid reproduction, it's called asexual reproduction, parthenogenesis. So it's essentially all female aphids giving birth to only females. And those females mature in about seven days or less. And then they're ready to give birth to live young. So it's a telescoping population and it can increase rapidly and that's why it's so important that you scout for aphids. They can literally explode when the temperatures are 72 to 80 degrees Fahrenheit. And they also have piercing sucking mouth parts. So when they insert and feed on the plant sap, they have to excrete all those proteins and other sugars they get from the plant, and they do that in the form of honeydew. And when there's high populations, your leaves can be very sticky. And then you might get black suiting mold growing on the honeydew. So aphids actually protect aphids because they like to feed on the honeydew. So you may see a lot of ants on plants that have a lot of aphids. So aphids are number one vectors of viruses and other diseases. They're over 200 different viruses and that's because of their feeding mechanism and their mouth parts. You can see there the stylet kind of looks like a knife. And they insert that right directly into the plant and the juices and feed on the clone level. And that's why there's just good transmitters of viruses. So that's a problem and that's why you don't want a lot of aphids on your plants because the viruses can already kill your plant. So when you look for damning symptoms, you may might look for some yellowing or some puckering on the leaves or stunting. And then you can also look for the black suiting mold, but that indicates fairly high levels. If you're going to have the mold growing and the sticky substances, a honeydew. So if you catch them early, you can use just physical control with a strong force of water at a high pressure to try and wash them off. Part of the problem is they're on the undersides of the leaves typically. So you do need to, you know, get to the underside of the leaf. Then I'm showing that for all the past, you know, just some general use insecticides and I didn't list all of them. There's great, you know, the homeowner has quite a selection of trade names, but not so many active ingredients. So I'm just listing the active ingredients here. And then bio-rational insecticides include botanicals, soaps, and microbial. And these would be the more type of insecticide that's labeled for organic. So here's some, and I'm not going to name them all for you, but you can just read it's on the slide. It's called neem oil, insecticide soap, Pagani, Cassasian. But anyway, there can be very notorious, but fortunately we have a lot of predators out there as well. Everyone's familiar with lady beetles. The adult and the lady beetle larvae consume them. In fact, adults can eat more than 300 aphids a day. And larvae, depending on the size, 30 to 50 aphids per day. So they're voracious predators. And also the Hoover fly or surfeit fly, these are good pollinators as the adult fly. But the larval stage is also excellent feeder of aphids consuming 400 or more aphids during its entire development as the larvae. And then there's lay swings. We got both the green and brown lay swing. The egg is kind of unusual laid up on the stock, but the larvae looks like an alligator and they too are known to be voracious aphid predators consuming about 200 aphids per week. And then there's parasoids or parasitic wasps that can attack aphids. They lay their eggs right into the body of the aphid and then it balloons up. And it kind of looks like a mummy. So that's what we call them as a mummy because they kind of turn white. And then when they're done eating out the inside of the aphid, they'll kind of end up a circular hole at the end here. And the wasps will emerge and continue the cycle. So there's a lot of beneficial wasps that are out there killing many aphids. And then we also when we have moist conditions, we can get many diseases that attack the aphids. And if you see this on your leaf, that's good. This is one that's infected with a fungal disease and you can see the white mycelium here growing from the dead aphid body. Hey, moving on to caterpillars and lepidoptera. There's many different types of caterpillars. But we'll be talking about true caterpillars and the lepidoptera. And this includes both moss and butterflies. And the adults are not damaging to our flower plants. They're pollinators and have siphoning low parts that feed on nectar and pollen. And I'm going to talk mainly about the variegated cat worm, which is in the family, not to a day. This one's common in our gardens. I know I've had it. And then some that we want to attract, like we want to get caterpillars in. So these aren't the past, but I'm just listening. Sometimes we don't want a caterpillar feeding on our plants and other times we do, we do. So the larvae, as you can see, have large spandibles that are chewing. And here's the mature variegated cat worm larvae. It can grow to almost two inches when it's mature and also plant damages caused by the larval stage. It causes mainly defoliation. You'll see holes in the leaves, skeletonization, or even chew holes into the buds of flowers. And they feed primarily at night in the family noctua, which means night. And then they hide during the day. So if you're looking around, you're seeing a lot of defoliation, maybe a cut plant off. But it's probably a cut worm and it's been, you know, it's underneath the litter and look around under the mulch, and you might find it. Sometimes you have to dig down an inch or two with a trowel because they don't like the daytime and they like a little bit of moisture as well. But many of the ones in the garden are called timing cutworms because they climb up onto the plant and feed on the foliage and flowers. But many other cutworms too, like in their vegetable garden will feed on the roots or cut the stem right off. And there's quite a few different general use insecticides that are available. Also, I want to point out here, we have Bacillus thuringiensis carthachii, which is a bacterial insecticide. It's very effective against the young larvae, so you need to get it on in the early growth stages of the larval stage, but it does an excellent job. And again, you want to control them when they're smaller and younger, because they're much easier than the large mature cutworms. And I also advocate that you spray at night time. And again, you know, you might see this little guy up at the top here, this is a this little caterpillar, and it looks like it would be a terrible past. But if you're gardening for butterflies, this is the painted lady butterfly. So this is what the caterpillar looks like the spiny guy here. And they make nice little webs, webs and nest in the leaves. So there's a lot of bio control action out there as well. If you look around in the environment is white, right, we have high humidity, warm temperatures. We can get fungal and viral diseases and have epizodic outbreaks. And this is what happens when they get a viral infection, they become just a blob. And here's one that's infected but not quite as far as long as this one and this is how the virus spreads it goes out and drips on to other leaves that might have a caterpillar crawling on it. And this is a fungal infected one here hanging down. And these two pictures down here at the bottom are infected with parasitic wasp. This one has an ectoparasitic wasp and this one has field its whole body is filled with cocoons of the parasitic wasp and they're getting ready to emerge. And of course there's many predators, you know, birds rely on our caterpillars so that's why I encourage you not to spray. If you don't have a lot of them. And there's many other insects that also prey on caterpillars. So they're important food source. Moving on to saw, saw flies and hymenoptera, which is the wasp. There are many different types of soft flies but this particular one I call has the no ways it doesn't have thin waste that lot of wasp do. And the soft flies are very specific so they usually only attack one group of plants so like the rose soft fly or the Columbine soft fly. I'm going to talk mainly about the Columbine soft fly. I'm probably not going to see the wasp unless you're really closely inspecting the plants daily. It's black and it has pale orange legs. And then here you can see the caterpillar or the immature stage and note that these are pro legs are not true caterpillars, because they have more six or more pro legs you can see here. The rest of the body's hidden there, but they get quite large or about half inch long when they're mature and beautiful green so they blend in with the fall age and a brown head. And they're usually active late spring so you know to go out and look for them late spring, April to June and the feed for about two to three weeks to complete the larval development. And the host is just Columbine. And here this is my plant garden, and you can see it just they just completely defoliated it. And I have a couple others that were actually worse, but the chili mouth parts will completely default. We move all the fallage and skeletonize it. And sometimes you know this is why you end up with just some of the flowers. But I did finally was forced to spray for it. And you need to inspect them frequently in the spring, especially if you know you have them, because they they pupate in the ground here. So they'll be back next year. And so you need to control them as soon as possible. And there's a couple things you can do you can pick them off and put them into a container of soapy water, something like what we do with Japanese beetles. If you had came from an area or no, no of Japanese beetles. And then there is some general use of insecticides on the market, and then also some of the bio rationales. But you might think the BT insecticide will work that worked with the moth and butter, butterfly. Well, you don't want to kill the butterflies, but the moth caterpillars. But it does not work because these are not true caterpillars because they have more than six abdominal pro legs. So it won't work on them. So don't use that bio control and there's a lot of parasitic wasps that do attack them and then the birds also love them and they are slower acting all the parasitic wasps. It's kind of a delayed effect. And then there are leaf finders, dip drop flies, agri-mysidae. These are very tiny flies and again they're kind of hard to observe. They got multiple generations. And they'll lay their eggs in the leaves. You can see these are the egg lane sites on the leaves. The larvae will hatch. Here's some that have been pulled outside of the mind, and then they mine the leaf tissue. So what you're most likely going to see is the leaf tissue, but do look for these overposition or egg lane sites. And again, these don't really harm the health of the plant, but they, you know, it's unsightly to see these mines in the beautiful green leaves. There's two. Two, there's phytomyzas, the genus, and one that's common here in the Midwest is the one that causes the serpentine mines and trails and the leaves and the other one is the blotch. Now I have both where I have my column mine. So I think we have both here, but they can have up to three generations per year. So again, physical control is crushing the larvae with your fingers and the mines, or you can prune the leaves off and then the plant will refoliate and dispose of the leaves. And then there is some insecticide guidance here. As soon as you see those egg punctures, you need to get a spray on for the adults and the newly hatched larvae before they mine into the leaf. Because the insecticide control is very difficult, so we have to focus at the adult and trying to kill it so it doesn't lay as many eggs because the larvae are protected inside between the plant leaves. So there's some sprays. I wouldn't recommend a medical spread because this is very highly toxic to bees. Try to stick away from the neonicotinoid insecticides. And then there's some bio-rational insecticide. So you can use, again, you may need to spray more often with a bio-rational insecticide, but they're not as toxic to bees and other butterflies. There's parasitoids as well that attack both the egg and larvae. Thrips, thancinoptera. They're very tiny and you usually don't see them. You'll see the damage first. So they're only about an eighth of an inch. The adult has fringe wings and the immature has no wings and it's usually white to yellow. In color, here's an egg. And they have rasping sucking mouth parts, so they kind of rash away at the leaf green tissue and then they feed on the plant sap. And they can also vector viruses, although they're not as bad as the aphids are. If you disturb them, they'll jump or the adult can also fly away. And they love flowers. Roses, clads and irises are their favorite. And in the leaves, you can see a couple here, but they also cause the puckering and you can see some stippling here. Here's a couple of stipple points. They can also cause some stippling on the leaves. But the buds and the flowers don't open up and then you'll may see some discoloration. Here you can see some browning due to the thrips feeding and this white is also caused from the thrips feeding this discoloration here. And they do the worst when it's hot dry like last year. And I have my lads on the south side of the house where it's hot and dry. And I didn't get any flowers this last year due to thrips. I didn't spray for them but I just cut them off because it was too late. And here's the yellow and blue traps. Again, there's clearly selection of insecticides if you're interested in using them. You can also get a predator mite, Phytosia day. It's commercially available and you can buy that through some suppliers if you're interested. And then ending here on a non-insect, a spider mite. It's more closely related to a spider than an insect. But we have two spotted spider mites a lot too when it's hot and dry. And they're very, very tiny as you can see in this picture. The most common one is the two spotted spider mite which has this two brown spots on the sides of the abdomen. And they're usually on the undersides of the leaf and they start to work their way up the plant from the bottom. So they start at the bottom leaves and then slowly work their way up. And here you can see as the name spider implies webbing. They do a lot of webbing and that's how they disperse and get to other plants. This is a flower head that's just covered with mites. So they can have a lot of over 500 different hosts, trees, ornamentals, and crops. And they over winter in the egg stage, usually on alfalfa and other permanent types of vegetation. Here you can see the life stage. They have eight legs as the adult but in the nymph stage you only have six legs. So you could confuse it with an insect which only has six legs then. But it takes five to 19 days depending on the temperature. And of course the reproduction cycle is faster when it's hotter. And they have piercing sucking mouth parts just like the aphids and they feed on the little plant cells and extract the green tissue. And it ends up looking like a bunch of stipples or stippling on the leaves and or little white spots and then the leaves will go yellow after that and then bronze and then under a severe infestation will just drop right off. It won't let it get to that point. And the green tissue is very important to the plants that house the plant makes food. So it results in the loss of photosynthetic ability and water loss in the plant. So you're going to end up reduce figure and small or no flowers on the plant if you have a severe mite infestation. And the sample for them as a white sheet of paper underneath the plant and wrap with a stick and dislodge the lights onto the white sheet of paper. You'll need a hand lens to look for them. They're very slow moving on that piece of paper. You can also use what we use for aphids that strong force of water. You'll have to do it multiple times though for mates. Insecticides, I put a question mark by Perethrins, Paganics, because they don't generally work is close related to Perethrites, Insecticides, and they generally flare mites. So the label have mites on there, but I question whether it's wise idea to use Paganic or other Perethrins like from the chrysanthemum flower. So I'd stick with me or insecticidal soap or spinosa. So there's a lot of natural enemies, pirate bug, lady beetle, adult and larvae, and you can commercially get these predatory mites, which will eat them. There's several different types of predatory mites. It's important when you're sampling, you're most likely going to see these predatory mites are out there, and they have longer legs, and they move much faster to catch its prey. So when you're sampling with your white sheet of paper, you'll probably see some of these as well. And they're available commercially. Again, if you're going to use any insecticides, you know, avoid spraying blooming plants. If you can select a more least toxic pesticide or formulation, and then spray in the evenings when the temperatures are below 55. I realize sometimes it doesn't get that cold in the evenings during the middle of summer, but again, late evening is when they go back to the hives, bumblebees are more active longer. I use a short residual insecticide if possible. And sometimes I cut my flowers off so it's not attractive at all to any pollinator, if I have to spray. And here's some extension pollinator publications that you might be interested in. I'm working on the insect pests, the Barticota flower gardens. I keep revising it. I've been working on it for a while now, but I keep learning new things that I want to stick into it. So it'll be coming out this May, June. And with that, I'd like to conclude and we can move to the questions. Certainly you talked about some bio-rational insecticides. Yep. Can they hurt pollinators? Well, it depends on which one you're talking about. Yeah, some of their generalists, a lot of them like me, is a generalist insecticide. It kills a lot of different insects. So if you spray it onto the flowers and a butterfly comes and feeds it, you might not kill it, but it depends. It would probably make it sick or some of them are very susceptible. So yeah, it's hard to say, but yeah, any insecticide will kill a pollinator. And then if you give it a high enough concentration and it depends if it's dried, once they dry, insecticides become much safer. But if it comes into contact with it when it's still wet or it flies through when you're spraying, it's most likely going to die. That's why you recommend spraying at night. How about the Japanese beetle? You mentioned about picking them off and throwing them in soapy water. Do sticky traps work or do you have any other tips to manage Japanese beetle? It's a large beetle, the Japanese beetle, and it's not very common yet here in North Dakota, but we do have it. It's mainly out at the nurseries. And it's the most recent survey that was done last year indicates that we have the highest population in the eastern side of the state in Grand Forks and Fargo. It is out in Bismarck though as well and might not. Yeah, it's a huge beetle. So I don't think the sticky traps would work very well because they are so strong. The larger insects can just get on it, but they can also get off the trap. But there is a pheromone trap that you can use, but I wouldn't recommend it because the pheromone is so strong and powerful. You're actually drawing them in from the whole area. So you're going to probably end up with more Japanese beetles than what you started with. So that's why a Japanese beetle trap is very effective, but you should give it as a gift to your neighbor. There you go. They'll be so happy to see all those beetles. I think you gave them a great gift. And just walk back in your home and smile about thank you for taking every beetle in the neighborhood away from us. Yeah, hopefully we won't end up getting them here. Our winters are a little more severe like they have in Minneapolis. Yeah, I like that about you, Jane. You're such an optimist about things. But how about, Jane, how about some negative thought here? There's a comment here that are we in danger of a yellow and black spider entering the US? That looks like a yellow and black garden spider. Have you heard of that? I haven't heard about that, but usually spiders come from the South America, Central America, where it's warmer. And I don't think they'll do as well. Certainly they won't do well here in North Dakota if it's being introduced. That's where the spider originated from. But they may be able to survive down in Southern Florida and Texas. But thank goodness for the colder weather. Every time it's 25 below or 30 below, we should be thankful, right? Yes, that's why we don't have as many poisonous spiders here in North Dakota. Hitchhike happened in North Dakota and they're just temporary. How about, do you have any comments about using spin-o-sad for insect control? No, I've used it. It's probably one of the better bio-rational insecticides for flea beetles on your garden crops. It's a very difficult insect to control and on your vegetables. And it's very effective against some, you know, quite a few different insects. So yeah, no, that's a good, you know, I'm glad that we have it. It's based off of, I don't think it's organic registered, but because it's a bacteria that has to be synthesized. It's a natural grade. It came from a rum distillery in the Caribbean. How about that? It's pretty cool. Okay, let's say we like milkweed because it attracts the monarch. But what if our milkweed has aphids? What can we do? Oh, yes, I had thousands on my milkweed. I just let them go. I like them. I have a lot of beneficial insects on them, eating them, although the reproduction rate of the aphids quickly covered the whole plant. And it actually was affecting my monarch larvae. They didn't like that. So, but I didn't do anything. But again, if I had them, and I wanted to get rid of them, I try the water and probably a strong force of water several times. And you can also, some people will take a wipe, like a hand disinfectant wipe and use that to wipe along the leaves. And if you don't have a lot of plants, you could do something like that. There's a question here. How come for those aphids, you didn't buy a crate of ladybugs to eat them? Well, part of the problems with buying some of the commercially available lady beetles and so forth is once you release them, their tendency is to disperse and not stay where you put them. So that's part of the problem. They work well in greenhouses where they're contained in a contained environment where they can't get out. But in the garden setting, a lot of the beneficials will move out of your garden, even if there is host, because that's what their nature tells them to do. Okay. How about, can I use neem or insecticide also too often? Can you hurt the plants by spraying them too much? Yes, it can be a little, it depends on the formulation, but it can be. I did some work when I was in Maryland at the USDA ARS. In fact, I did some of the work that got it registered as an insecticide. So it was before it was even registered. But yeah, we tried some really high rates on chrysanthemum and we did see some phytotoxic burn. Especially if you spray it and there's a real strong sunshine, or it's really hot. Okay, we talked earlier about using water against aphids. How about water against mites? In either case, when you knock them down with a jet spray of water, do they just shake off the water and climb back up? I know it has to be hard enough to actually physically wash them off the plant, and then they usually end up drowning on the ground. Okay, that's good news. Yeah. About this person gets aphids or mites that they notice when they bring their outdoor plants inside in the late fall. Do you have any solutions while we can do that? Into the house. Yeah, like, you know, like you got some house plants out in the deck and then you bring them inside. And then he notices aphids or mites on them. In that case, it's okay to use a soil drench with a metacloprid, the neonicotinoid, because you're not going to have any bees buzzing around in the house or butterflies. So you'd be okay to use one of the soil drenches, or you could use any of the synthetic insecticides or the biorationals, whichever you prefer. But the systemic, the neonicotinoids are systemic, so they're taken up by the roots of the plant and translocated throughout the leaves. And then when the aphids or mites feed on the plant uses, they'll imbibe the insecticide and die eventually. Okay, this person has issues with wasps in the fall, and they're worried about killing the wasps with chemicals because they don't want to harm the bees. Do you have any recommendations for that? They're probably hornets. I assume. Sure, or yellow jackets. Yellow jackets, yeah. Yeah, they're, especially if they're close to the house, they can be dangerous if you have somebody who's allergic to the stings. So it's good to get rid of them. Usually they're nest in very small areas like under a porch or in between the walls in your house. So they're, you spray it the late evening, and I often recommend a professional because they can sting and repeatedly sting you. They're not like a honeybee stinger. So you don't want to, you know, have them stinging you. So I, you can get rid of them because they're really not in your flowers. So where you're spraying is usually into the ground, they are ground nesters as well. They'll go underneath your patio. If there's no stone there, they might get underneath there and build a nest into the ground, or if they could be in the siding of your house, or I've had some get into chimneys even. Got a few calls so they can get anywhere, but I had them in the siding of my house. And I had, I tried spraying but the problem with the sprayers homeowners have, they don't have enough force to get it all the way up where the nest is because you need to kill the queen of the nest to be successful in removing all the wasps. So we're just going to wind this up really quickly here, just quick answers. So this penis, they have damage on the leaves. It looks like they were cut with serrated scissors. Oh yeah, there's a weevil that does that on the penis and there's leaf cutter bees as well. So you'd have to see which one you have. The weevil does actually does some damage to the roots and feeds on the roots. But the adult just makes the funny cuts on the beanies. But it could be leaf cutter bees as well. They nest in the tubes. If you put out the houses in the bee hotels, they'll bring back little leaves half moon shape. Okay, so, you know, just going to answer a couple questions like there is a fan of that be beautiful publication that you have and they want to know how to get a copy you can just go online. No problem with that. And how about one last question is the milkweed toxic moth larvae detrimental to the monarch larvae. Yes, I had that as well on my milkweed and they did move my, I ended up taking the monarch larvae and I moved it myself to and that wasn't invested with the toxic moth because yeah they do compete for the same resource. And I, from what I saw the toxic moths will out compete the monarch larvae. So thank you, Chan. Thank you for all the great tips.