1 00:00:01,100 --> 00:00:02,360 Bodie Pennisi: Welcome back, everyone. 2 00:00:03,400 --> 00:00:09,040 Bodie Pennisi: Our second speaker is Dr. Ignazio Graziosi, who is an assistant professor in Warnell School 3 00:00:09,160 --> 00:00:11,080 Bodie Pennisi: of Forestry at University of Georgia. 4 00:00:12,200 --> 00:00:17,240 Bodie Pennisi: Dr. Graziosi studies tree health and raises awareness of the benefits provided by trees. 5 00:00:17,980 --> 00:00:21,920 Bodie Pennisi: As a field biologist, he has studied the impact of invasive species. 6 00:00:21,400 --> 00:00:26,660 Bodie Pennisi: insects and microorganisms on tree health and used this knowledge to develop management 7 00:00:26,810 --> 00:00:32,000 Bodie Pennisi: and surveillance tools while engaging land managers and the public in education programs. 8 00:00:33,100 --> 00:00:37,680 Bodie Pennisi: In his early career as a forester, he focused on the management of natural and urban tree 9 00:00:37,920 --> 00:00:44,540 Bodie Pennisi: Dr. Graziosi has held positions with non-governmental and governmental organizations, universities, 10 00:00:45,380 --> 00:00:47,180 Bodie Pennisi: and private companies in different countries. 11 00:00:47,990 --> 00:00:52,960 Bodie Pennisi: His work involves field and laboratory studies, data collection and analysis, development of 12 00:00:53,220 --> 00:00:59,640 Bodie Pennisi: protocols, use of photography, team project and partnership coordination, capacity building, 13 00:00:59,920 --> 00:01:01,380 Bodie Pennisi: education and analysis. 14 00:01:00,920 --> 00:01:05,480 Bodie Pennisi: outreach. And Dr. Graziosi, the floor is yours from Italy. 15 00:01:07,680 --> 00:01:10,840 Ignazio Graziosi: Thank you. Thank you, Bodie. Good afternoon, everybody. 16 00:01:11,880 --> 00:01:16,420 Ignazio Graziosi: Give me one sec that I'm going to click the magic button. 17 00:01:18,100 --> 00:01:18,940 Ignazio Graziosi: All right. 18 00:01:19,160 --> 00:01:21,140 Ignazio Graziosi: Can you hear me all right and see my screen? 19 00:01:21,700 --> 00:01:21,940 Ignazio Graziosi: Yeah. 20 00:01:22,140 --> 00:01:22,320 Ignazio Graziosi: Yes. 21 00:01:22,979 --> 00:01:23,500 Ignazio Graziosi: Fantastic. 22 00:01:24,650 --> 00:01:24,800 Ignazio Graziosi: Okay. 23 00:01:24,910 --> 00:01:26,440 Ignazio Graziosi: It's great to be here. 24 00:01:26,440 --> 00:01:26,680 Ignazio Graziosi: Looks perfect. 25 00:01:27,190 --> 00:01:27,860 Ignazio Graziosi: Thank you again. 26 00:01:28,479 --> 00:01:34,260 Ignazio Graziosi: So we are all dealing with the variety of different tree pests. 27 00:01:34,700 --> 00:01:37,020 Ignazio Graziosi: You can see on the screen a couple of examples. 28 00:01:37,720 --> 00:01:39,620 Ignazio Graziosi: There is a woolly adelgid. 29 00:01:39,970 --> 00:01:44,100 Ignazio Graziosi: We have fall webworm, caterpillar, beetles. 30 00:01:44,620 --> 00:01:51,960 Ignazio Graziosi: scales, and we tend to concentrate on the pest itself because it's what 31 00:01:52,340 --> 00:01:58,140 Ignazio Graziosi: produces damage to our trees. But it is important to remember that it is always a 32 00:01:58,440 --> 00:02:04,420 Ignazio Graziosi: team result. We have the pest, yes, but there are other actors in 33 00:02:04,280 --> 00:02:13,640 Ignazio Graziosi: In the picture that caused the overall damage, of course, we have the tree itself and we have the environment. 34 00:02:14,560 --> 00:02:27,540 Ignazio Graziosi: And the damage on the tree, the damage from the pest and from the disease, is caused by the interaction of these three components. 35 00:02:28,100 --> 00:02:32,240 Ignazio Graziosi: And this is the concept of the disease triangle. 36 00:02:32,800 --> 00:02:36,220 Ignazio Graziosi: So the damage is not caused by just one component. 37 00:02:36,840 --> 00:02:46,720 Ignazio Graziosi: The pest alone is not enough, but is the interaction with the tree, which, for example, is susceptible, and the environment. 38 00:02:47,740 --> 00:02:57,080 Ignazio Graziosi: And we are dealing with trees, especially in the landscape, for the focus of this webinar, and in urban environment. 39 00:02:57,520 --> 00:03:01,700 Ignazio Graziosi: And in those environments, the situation gets worse. 40 00:03:02,240 --> 00:03:06,640 Ignazio Graziosi: And I introduced to you that spiral of tree decline. 41 00:03:06,980 --> 00:03:16,880 Ignazio Graziosi: And this is a diagram that was developed in the 90s and is really useful to understand this concept one step more. 42 00:03:18,220 --> 00:03:20,760 Ignazio Graziosi: So how does this diagram work? 43 00:03:21,080 --> 00:03:25,440 Ignazio Graziosi: So you see three different levels of spirals. 44 00:03:25,920 --> 00:03:34,200 Ignazio Graziosi: Each spiral is a family of factors that add stress to the tree at different levels. 45 00:03:34,810 --> 00:03:43,660 Ignazio Graziosi: A lot of those are similar to the stressor that Dr. Klein presented at the beginning of his presentation. 46 00:03:44,280 --> 00:03:52,780 Ignazio Graziosi: And all these different family of stressors, they end up eventually with the death of the tree. 47 00:03:53,180 --> 00:03:58,560 Ignazio Graziosi: And you see at the center of the death spiral, there is in fact the death of the tree. 48 00:03:58,939 --> 00:04:04,680 Ignazio Graziosi: And if we look at those three spirals one by one, we can see, for example, 49 00:04:04,840 --> 00:04:08,079 Ignazio Graziosi: the first one that is called the predisposing factor. 50 00:04:08,420 --> 00:04:13,920 Ignazio Graziosi: general stressor. The urban environment of course is stressful for the tree, there is the genetic 51 00:04:14,300 --> 00:04:21,959 Ignazio Graziosi: potential of the tree itself, and again it's a demonstration that the disease triangle is really 52 00:04:22,200 --> 00:04:31,420 Ignazio Graziosi: important. And then we have well-known stressor like soil compaction, which is often the number one issue for many 53 00:04:31,880 --> 00:04:41,480 Ignazio Graziosi: trees. And then we have another spiral that is closer to the center of our death spiral, 54 00:04:41,680 --> 00:04:48,180 Ignazio Graziosi: which is called here inciting factor, and we have defoliating insects, for example, we have drought 55 00:04:48,540 --> 00:04:54,820 Ignazio Graziosi: And then we have an even more internal spiral which is contributing factor, 56 00:04:55,210 --> 00:04:57,440 Ignazio Graziosi: and you see a lot of biotic factor. 57 00:04:57,610 --> 00:05:03,820 Ignazio Graziosi: You have fungi, wood boring insects, nematodes, Armillaria for example. 58 00:05:04,400 --> 00:05:21,900 Ignazio Graziosi: The important thing to understand of this diagram is that each of the spiral, the predisposing factor, the inciting factor, and the contributive factor, contain factors that can directly bring the tree to death. 59 00:05:22,480 --> 00:05:29,240 Ignazio Graziosi: If you see, I'm not sure if you are able to see my pointer that I'm using on the screen. 60 00:05:29,360 --> 00:05:29,940 Bodie Pennisi: Yes, we are. 61 00:05:30,560 --> 00:05:31,040 Ignazio Graziosi: Fantastic. 62 00:05:31,620 --> 00:05:32,480 Ignazio Graziosi: Thank you, Bodie. 63 00:05:32,900 --> 00:05:36,000 Ignazio Graziosi: And you can see these lines here. 64 00:05:36,540 --> 00:05:42,500 Ignazio Graziosi: These lines means that each of these factors, for example, urban environmental factors, 65 00:05:42,600 --> 00:05:48,880 Ignazio Graziosi: urban environment alone or soil compaction alone are able to cut through the different 66 00:05:49,280 --> 00:05:54,160 Ignazio Graziosi: layers of the spiral and bring the tree directly to death. 67 00:05:54,540 --> 00:06:01,100 Ignazio Graziosi: One important message to take home from this diagram is that the health of the tree and 68 00:06:01,420 --> 00:06:06,060 Ignazio Graziosi: potentially the death of the tree is an interaction between many factors. 69 00:06:07,060 --> 00:06:14,580 Ignazio Graziosi: And if we go back to our slide, visualizing different pests that we have to deal with, 70 00:06:14,880 --> 00:06:18,280 Ignazio Graziosi: we have here non-native pests. 71 00:06:18,460 --> 00:06:20,460 Ignazio Graziosi: We have examples of native pests. 72 00:06:20,639 --> 00:06:27,160 Ignazio Graziosi: We have examples of native trees, examples of also exotic trees. 73 00:06:27,580 --> 00:06:33,060 Ignazio Graziosi: And understanding the interaction among those native pests, 74 00:06:33,240 --> 00:06:41,560 Ignazio Graziosi: attacking native trees and vice versa, non-native attacking native and native attacking non-native 75 00:06:41,820 --> 00:06:45,960 Ignazio Graziosi: is really important because allow us to understand the mechanism 76 00:06:46,820 --> 00:06:55,120 Ignazio Graziosi: and to understand what are the general strategies we can use to manage and control those pests 77 00:06:55,540 --> 00:06:59,199 Ignazio Graziosi: and this is true for many different pests. 78 00:06:59,669 --> 00:07:02,639 Ignazio Graziosi: So I'm bringing to you three examples, 79 00:07:03,400 --> 00:07:05,380 Ignazio Graziosi: three stories if you want, 80 00:07:05,919 --> 00:07:09,759 Ignazio Graziosi: that investigate, explore different scenarios 81 00:07:10,820 --> 00:07:15,440 Ignazio Graziosi: and present to us some important component of this interaction 82 00:07:15,910 --> 00:07:21,740 Ignazio Graziosi: that will help us to deal in the future with a variety of different pests. 83 00:07:22,580 --> 00:07:31,940 Ignazio Graziosi: So the first one, the first example, the first story for you is a native tree impacted by non-native pest. 84 00:07:32,540 --> 00:07:41,160 Ignazio Graziosi: And this is the very famous case, the superstar of insect pests, the emerald ash borer. 85 00:07:41,690 --> 00:07:47,380 Ignazio Graziosi: So the emerald ash borer, I'm sure many of you are familiar with it on the picture on the left, 86 00:07:47,720 --> 00:07:50,480 Ignazio Graziosi: is a canopy dieback caused by the insect. 87 00:07:51,160 --> 00:07:56,780 Ignazio Graziosi: And remember, when you see canopy dieback caused by the emerald ash borer 88 00:07:57,240 --> 00:08:03,200 Ignazio Graziosi: and you identify the problem to be that, the emerald ash borer, 89 00:08:03,560 --> 00:08:09,660 Ignazio Graziosi: that means that the insect has been spreading in the area for at least 5 to 10 years. 90 00:08:10,600 --> 00:08:16,040 Ignazio Graziosi: And then you see on the right that is the damage at a stand or forest level. 91 00:08:16,860 --> 00:08:22,500 Ignazio Graziosi: So a very quick summary of what is the EAB, emerald ash borer, about. 92 00:08:23,460 --> 00:08:31,400 Ignazio Graziosi: So larvae feed under the bark and doing so disrupt the phloem, the cambium, the outer xylem, 93 00:08:31,820 --> 00:08:35,300 Ignazio Graziosi: and it cuts off the movement of nutrient and water. 94 00:08:35,740 --> 00:08:38,780 Ignazio Graziosi: And trees, they can die very fast. 95 00:08:38,820 --> 00:08:42,620 Ignazio Graziosi: This is an overview of how the damage happened. 96 00:08:43,219 --> 00:08:49,360 Ignazio Graziosi: And if you start from the picture on the left, you see a young tree that is debarked, and 97 00:08:49,360 --> 00:08:55,959 Ignazio Graziosi: you see the gallery caused by the feeding larvae, and you see that the tree is desperately 98 00:08:56,290 --> 00:08:57,260 Ignazio Graziosi: trying to sprout. 99 00:08:58,020 --> 00:09:03,640 Ignazio Graziosi: has a reaction to the attack and the water sprouts are actually a very important diagnostic 100 00:09:04,760 --> 00:09:09,720 Ignazio Graziosi: feature in order to understand if a tree is attacked by the emerald ash borer. 101 00:09:10,180 --> 00:09:15,980 Ignazio Graziosi: And if you get closer to the tree, you can actually see the larvae, like here, that is feeding. 102 00:09:16,100 --> 00:09:23,540 Ignazio Graziosi: This is a fourth instar, is a mature larva, is probably around two inches long, 103 00:09:24,540 --> 00:09:30,240 Ignazio Graziosi: And by feeding, it basically disrupts all the cambium tissue and the outer xylem. 104 00:09:30,759 --> 00:09:35,240 Ignazio Graziosi: And then, after the larva, completed the larva development, 105 00:09:35,860 --> 00:09:38,540 Ignazio Graziosi: which is usually at the end of the season, 106 00:09:39,019 --> 00:09:46,459 Ignazio Graziosi: it folds in a J-shape and gets a little bit deeper in the outer wood, 107 00:09:47,060 --> 00:09:53,819 Ignazio Graziosi: and it starts kind of slipping, and overwinter is called J-larva, or prepupa. 108 00:09:54,520 --> 00:10:04,080 Ignazio Graziosi: pupa. And then at the end of the winter, pupate and emerge in spring. You can see the shiny 109 00:10:04,290 --> 00:10:10,980 Ignazio Graziosi: green beetle that is emerging from a tree. And while it emerge, it leaves through a very 110 00:10:11,180 --> 00:10:14,720 Ignazio Graziosi: characteristic, the famous D-shaped exit hole. 111 00:10:15,340 --> 00:10:20,120 Ignazio Graziosi: This is another way to represent the life cycle of the insect. 112 00:10:20,410 --> 00:10:26,740 Ignazio Graziosi: We can start from here, where the insect again comes out from the tree, 113 00:10:27,200 --> 00:10:34,540 Ignazio Graziosi: leaving the D-shaped hole, and then mate, female, lay eggs in the crack of the barks. 114 00:10:34,920 --> 00:10:43,839 Ignazio Graziosi: from the egg, a larva hatch goes through the bark and starts feeding and causing the gallery you already seen on the previous photos. 115 00:10:44,300 --> 00:10:48,560 Ignazio Graziosi: And then pupate and will emerge again the following years. 116 00:10:48,959 --> 00:10:56,540 Ignazio Graziosi: Here it is important to remember that this is usually mostly a one generation per year insect. 117 00:10:57,220 --> 00:11:03,580 Ignazio Graziosi: But there is always a part of the population of the emerald ash borer in any location 118 00:11:04,360 --> 00:11:08,780 Ignazio Graziosi: that requires two years instead of one to develop. 119 00:11:09,300 --> 00:11:13,180 Ignazio Graziosi: And this is true especially in the northern part of North America, 120 00:11:13,480 --> 00:11:15,100 Ignazio Graziosi: where temperatures are lower. 121 00:11:15,600 --> 00:11:22,180 Ignazio Graziosi: As we know, temperature usually increases the development of insects. 122 00:11:22,300 --> 00:11:30,080 Ignazio Graziosi: And so the colder it is, the slower it develops. So at northern latitude in North America, the 123 00:11:30,180 --> 00:11:35,640 Ignazio Graziosi: emerald ash borer, a larger part of the local populations of emerald ash borer, 124 00:11:36,300 --> 00:11:42,700 Ignazio Graziosi: required two years to develop. And it is important to know when we have to deal with this insect to control it. 125 00:11:42,700 --> 00:11:56,940 Ignazio Graziosi: It was found, was discovered in 2002 in the Detroit area, which means again, as I pointed out earlier, that was present in the area already at least for 10 years. 126 00:11:57,720 --> 00:12:00,480 Ignazio Graziosi: And then you see all the little red dots. 127 00:12:00,720 --> 00:12:04,480 Ignazio Graziosi: Yes, it took North America, as we know, by storm. 128 00:12:04,840 --> 00:12:08,540 Ignazio Graziosi: This is one of the last available map from USDA. 129 00:12:08,940 --> 00:12:16,080 Ignazio Graziosi: This is 2023, because in 2021, I believe, the quarantine was lifted. 130 00:12:16,740 --> 00:12:18,580 Ignazio Graziosi: at federal level. 131 00:12:18,650 --> 00:12:24,700 Ignazio Graziosi: It was lifted because there was no hope to contain the insect through quarantine. 132 00:12:25,430 --> 00:12:36,400 Ignazio Graziosi: And then the invasion of North America by the EAB was caused by one single individual cause. 133 00:12:36,610 --> 00:12:44,200 Ignazio Graziosi: There was one culprit that allowed the EAB to move so quickly all over the United States. 134 00:12:44,520 --> 00:12:50,560 Ignazio Graziosi: And I let you guess and you can write your answer if you have an idea in the chat box. 135 00:12:50,850 --> 00:12:56,240 Ignazio Graziosi: I will not be able to see it right now, but I will go later and check. 136 00:12:57,500 --> 00:13:00,400 Ignazio Graziosi: And this is, of course, firewood. 137 00:13:02,140 --> 00:13:08,880 Ignazio Graziosi: campers and travelers, they move infested firewood to the next city, to the next country, 138 00:13:08,900 --> 00:13:10,240 Ignazio Graziosi: to the next state. 139 00:13:10,880 --> 00:13:17,000 Ignazio Graziosi: And this really is what determined a lot of the pathways of the invasion in North America. 140 00:13:17,520 --> 00:13:26,540 Ignazio Graziosi: They were able to connect very closely the pattern of the spread with the highway and 141 00:13:26,560 --> 00:13:27,660 Ignazio Graziosi: freeway system. 142 00:13:28,000 --> 00:13:36,100 Ignazio Graziosi: There is one good thing that came out from this disaster, which is the "Don't move firewood" campaign. 143 00:13:36,820 --> 00:13:46,460 Ignazio Graziosi: This is a very effective and important campaign that helps, for example, contain other invasive insects, such as the Asian longhorn beetle. 144 00:13:47,520 --> 00:13:54,800 Ignazio Graziosi: Okay, so we know that as the EAB spread in North America, attacked and impacted heavily 145 00:13:55,100 --> 00:13:56,900 Ignazio Graziosi: the native species of ash. 146 00:13:57,600 --> 00:14:03,520 Ignazio Graziosi: In Georgia, for example, there is of course the emerald ash borer, and this is a spread, is 147 00:14:03,520 --> 00:14:08,260 Ignazio Graziosi: I would say the southern edge of the invasion, so it's still spreading. 148 00:14:08,400 --> 00:14:10,480 Ignazio Graziosi: This map is from 2020. 149 00:14:10,620 --> 00:14:26,100 Ignazio Graziosi: So there is active surveillance is present in the Athens area, of course, and even a little bit southern. So you may think that is not very important, is not as important as 150 00:14:26,160 --> 00:14:30,779 Ignazio Graziosi: fighting against the emerald ash borer in Georgia comparing to other states. 151 00:14:30,940 --> 00:14:37,199 Ignazio Graziosi: It's true, there are other states where there is a continuous presence and availability of ash 152 00:14:37,579 --> 00:14:45,600 Ignazio Graziosi: and Georgia is more scattered. But if we start looking at the distribution of ash species 153 00:14:46,380 --> 00:14:53,000 Ignazio Graziosi: in Georgia, we see that it is really important for biodiversity and actually the state hosts 154 00:14:53,500 --> 00:14:55,240 Ignazio Graziosi: multiple species of ash. 155 00:14:55,350 --> 00:15:01,580 Ignazio Graziosi: We have green ash statewide, we have blue ash, which is an interesting tree because it shows 156 00:15:01,820 --> 00:15:05,000 Ignazio Graziosi: a little bit of resistance against the emerald ash borer. 157 00:15:05,380 --> 00:15:11,200 Ignazio Graziosi: It will die eventually, but it will take way longer compared to other species of ash. 158 00:15:11,360 --> 00:15:15,140 Ignazio Graziosi: We have white ash, Carolina ash, which is a southern ash. 159 00:15:15,380 --> 00:15:19,160 Ignazio Graziosi: We have Biltmore ash, which is a subspecies of white. 160 00:15:19,360 --> 00:15:22,660 Ignazio Graziosi: We have pumpkin ash on the southern part of the state, 161 00:15:23,420 --> 00:15:25,260 Ignazio Graziosi: swamp white and small ash. 162 00:15:26,200 --> 00:15:28,000 Ignazio Graziosi: And then there is another plant, 163 00:15:28,220 --> 00:15:37,100 Ignazio Graziosi: that unfortunately is important for the ecology of the emerald ash borer, and is a surprise that happened in 2014, 164 00:15:38,020 --> 00:15:45,860 Ignazio Graziosi: when they discovered that the EAB was able to, we say, expand its host range and attack a native 165 00:15:46,620 --> 00:15:52,360 Ignazio Graziosi: plant in North America, which is the white fringetree, which is the same family, Oleaceae, 166 00:15:52,820 --> 00:15:53,480 Ignazio Graziosi: of ash. 167 00:15:53,960 --> 00:15:57,180 Ignazio Graziosi: And this is present also in Georgia. 168 00:15:57,640 --> 00:16:03,100 Ignazio Graziosi: It's important to know that because not only it could be a damage for the white fringetree, 169 00:16:03,620 --> 00:16:10,880 Ignazio Graziosi: but more importantly, the white fringetree could function as a reservoir for the population 170 00:16:11,520 --> 00:16:13,800 Ignazio Graziosi: of the EAB, even though 171 00:16:13,899 --> 00:16:17,720 Ignazio Graziosi: all the other ash trees in the area are gone. 172 00:16:18,540 --> 00:16:22,660 Ignazio Graziosi: So the EAB can stay in an area utilizing the white fringetree. 173 00:16:24,300 --> 00:16:29,760 Ignazio Graziosi: Okay, so we know that the EAB is non-native and we know that it is from Asia. 174 00:16:30,279 --> 00:16:37,700 Ignazio Graziosi: So if we look at the map where it was in Asia and where it is now in North America spreading 175 00:16:37,740 --> 00:16:43,779 Ignazio Graziosi: and causing damage, we may ask how did it get there? Of course we know through 176 00:16:43,680 --> 00:16:54,440 Ignazio Graziosi: trade. This is a photo in the port of Savannah. And we know that this not accidental introduction 177 00:16:55,080 --> 00:17:02,540 Ignazio Graziosi: through trade of non-native species is not a new trend, but is an exponentially increasing trend. 178 00:17:03,160 --> 00:17:07,319 Ignazio Graziosi: And you can see here an example from different parts of the world. 179 00:17:07,760 --> 00:17:10,880 Ignazio Graziosi: So it is really exponentially increasing. 180 00:17:11,520 --> 00:17:16,980 Ignazio Graziosi: One reason is that our ability to detect species has increased as well, improved. 181 00:17:17,959 --> 00:17:24,319 Ignazio Graziosi: But trade is increasing, of course, and the introduction of non-native species is reflecting 182 00:17:24,520 --> 00:17:25,880 Ignazio Graziosi: this globalization. 183 00:17:28,300 --> 00:17:37,020 Ignazio Graziosi: If you go near potential port of entries, such as airport and port, you may notice traps. 184 00:17:37,660 --> 00:17:40,980 Ignazio Graziosi: This is a generic trap in the port of Savannah. 185 00:17:41,420 --> 00:17:44,760 Ignazio Graziosi: This is another example since we are talking about the EAB. 186 00:17:45,280 --> 00:17:49,160 Ignazio Graziosi: This is the trap that is designed to catch the EAB. 187 00:17:49,680 --> 00:17:56,480 Ignazio Graziosi: is a series of funnel, interconnected funnel. There is a pouch, which is the green pouch there, 188 00:17:56,980 --> 00:18:02,880 Ignazio Graziosi: that is a lure that produces an attractant for the EAB. The EAB arrives, 189 00:18:03,240 --> 00:18:08,080 Ignazio Graziosi: hits the funnel, and it falls in the cup. So this trap, 190 00:18:08,600 --> 00:18:14,280 Ignazio Graziosi: These type of traps, they are not designed to catch as many beetles as possible to remove 191 00:18:14,540 --> 00:18:15,600 Ignazio Graziosi: them from the environment. 192 00:18:16,240 --> 00:18:19,820 Ignazio Graziosi: It's just a detection, but it's a very important detection methodology. 193 00:18:20,820 --> 00:18:27,640 Ignazio Graziosi: Okay, we know of the damage, has the EAB spread in North America, it caused immense damage 194 00:18:28,000 --> 00:18:30,460 Ignazio Graziosi: to the native population of ash. 195 00:18:30,880 --> 00:18:33,200 Ignazio Graziosi: And we have another tool here I want to present. 196 00:18:33,520 --> 00:18:41,400 Ignazio Graziosi: to you, because it's a useful tool to understand the strategy to manage non-native and native 197 00:18:41,780 --> 00:18:50,040 Ignazio Graziosi: pests alike, which is the invasion curve. This is a diagram that illustrates the growth 198 00:18:50,560 --> 00:18:56,960 Ignazio Graziosi: of a population of a pest, which here is called pest prevalence, over time. 199 00:18:57,760 --> 00:19:03,960 Ignazio Graziosi: So the story starts with the introduction when the pests arrive in the area. 200 00:19:04,580 --> 00:19:11,380 Ignazio Graziosi: So the introduction, of course, after the introduction the population of the pests, the prevalence is still low. 201 00:19:11,960 --> 00:19:17,680 Ignazio Graziosi: And then start growing and start multiplying and feeding on the host. 202 00:19:18,420 --> 00:19:21,640 Ignazio Graziosi: And then it enters exponential growth. 203 00:19:22,260 --> 00:19:25,900 Ignazio Graziosi: And this is when land managers, for example, start to be aware. 204 00:19:27,000 --> 00:19:31,480 Ignazio Graziosi: And it's a little bit more time before the public starts to be aware. 205 00:19:32,060 --> 00:19:34,820 Ignazio Graziosi: And by the time the public starts to be aware, 206 00:19:35,260 --> 00:19:41,500 Ignazio Graziosi: usually the population is already really high until it reaches a... 207 00:19:41,800 --> 00:19:59,820 Ignazio Graziosi: plateau which is the so-called carrying capacity what is that for example is where or when all the ash-trees in the area are gone so the population of the pest cannot grow any more this diagram is important 208 00:20:00,920 --> 00:20:08,580 Ignazio Graziosi: because it can be connected with our ability to deal and control the pest. 209 00:20:08,770 --> 00:20:15,780 Ignazio Graziosi: When the population is really low, right after the introduction, we can even try to eradicate a pest. 210 00:20:16,120 --> 00:20:20,940 Ignazio Graziosi: Of course, it's very difficult, but in some cases, for some pests, it's not impossible. 211 00:20:21,460 --> 00:20:24,440 Ignazio Graziosi: We can do prevention, for example. 212 00:20:25,140 --> 00:20:32,720 Ignazio Graziosi: But then as the pest prevalence starts to grow, it's really impossible to eradicate. 213 00:20:34,360 --> 00:20:39,280 Ignazio Graziosi: And then the only control that is possible is a local control. 214 00:20:40,060 --> 00:20:43,420 Ignazio Graziosi: For example, just trying to save individual trees. 215 00:20:44,340 --> 00:20:59,700 Ignazio Graziosi: But as the prevalence and the difficulties of controlling a pest grows, the cost associated with the control grows as well. And this is really important to understand. And this is why... 216 00:21:00,240 --> 00:21:08,159 Ignazio Graziosi: detection is so important and ideally we want to have effective tools to detect a 217 00:21:08,399 --> 00:21:14,320 Ignazio Graziosi: test as close to the introduction event as possible because everything is easier 218 00:21:14,740 --> 00:21:15,480 Ignazio Graziosi: and is possible. 219 00:21:16,440 --> 00:21:25,220 Ignazio Graziosi: Okay, so as we understand how an invasion works, we can look at the map again and we 220 00:21:25,419 --> 00:21:31,660 Ignazio Graziosi: can ask ourselves, okay, we know that the emerald ash borer is non-native, is from Asia. 221 00:21:32,260 --> 00:21:48,300 Ignazio Graziosi: And is a pest here, but what about in its native range? What about in Asia? Was a pest? The answer is no. And there are multiple reasons for that, and they will relate to our disease triangle. We will see that. 222 00:21:48,440 --> 00:22:03,320 Ignazio Graziosi: The first reason is that the native species of ash in Asia, they say co-evolved with the pest, which means they are less susceptible or resistant. 223 00:22:04,400 --> 00:22:15,220 Ignazio Graziosi: And the only ash trees, Asian species of ash trees, that can be attacked by the EAB in Asia are very weak and stressed trees. 224 00:22:15,940 --> 00:22:30,500 Ignazio Graziosi: That's one important reason. And this is why the low susceptibility and the resistance, this is why one of the approaches to control the EAB is to artificially make 225 00:22:30,980 --> 00:22:34,260 Ignazio Graziosi: actually resistant through chemical protection. 226 00:22:34,580 --> 00:22:40,160 Ignazio Graziosi: Of course, this is just a visual summary of the technology that I'm sure you are familiar 227 00:22:40,960 --> 00:22:41,160 Ignazio Graziosi: to. 228 00:22:41,230 --> 00:22:44,380 Ignazio Graziosi: There is three injection, bark spray, and soil drench. 229 00:22:44,920 --> 00:22:52,780 Ignazio Graziosi: I want to give just a little flash and overview of the chemical control methodology for the 230 00:22:52,860 --> 00:22:53,340 Ignazio Graziosi: EAB. 231 00:22:54,760 --> 00:22:58,520 Ignazio Graziosi: And there are few involving systemic insecticides. 232 00:22:58,600 --> 00:23:02,460 Ignazio Graziosi: Some of them, they can be applied by homeowner. 233 00:23:02,900 --> 00:23:06,039 Ignazio Graziosi: Some of them, of course, they need a professional applicator. 234 00:23:06,760 --> 00:23:13,400 Ignazio Graziosi: And you have to choose carefully which one, depending on the season, for example, soil 235 00:23:13,500 --> 00:23:17,620 Ignazio Graziosi: drench needs to be applied in the spring before leaves are out. 236 00:23:17,720 --> 00:23:21,919 Ignazio Graziosi: I leave you here two links, two QR codes. 237 00:23:22,260 --> 00:23:24,480 Ignazio Graziosi: I encourage you to check them. 238 00:23:25,000 --> 00:23:33,000 Ignazio Graziosi: One is an overview of the state, the status, and the control of the EAB in Georgia. 239 00:23:33,659 --> 00:23:41,200 Ignazio Graziosi: And the one on the bottom on the left is the full protocol for insecticide control for the 240 00:23:41,260 --> 00:23:41,620 Ignazio Graziosi: EAB. 241 00:23:43,980 --> 00:23:50,980 Ignazio Graziosi: Ok, we are still trying to answer our question why is not a problem in Asia. 242 00:23:51,180 --> 00:23:56,660 Ignazio Graziosi: One reason is the trees are resistant, but there is another reason. 243 00:23:57,160 --> 00:24:03,140 Ignazio Graziosi: The other reason is that the population of the EAB there is kept in check by a community 244 00:24:03,140 --> 00:24:04,060 Ignazio Graziosi: of natural enemies. 245 00:24:04,740 --> 00:24:05,720 Ignazio Graziosi: These are predators. 246 00:24:06,560 --> 00:24:10,580 Ignazio Graziosi: are parasitoids, and we will see later what is a parasitoid, 247 00:24:10,910 --> 00:24:15,040 Ignazio Graziosi: that are able to attack the EAB and to keep the population low. 248 00:24:16,160 --> 00:24:21,920 Ignazio Graziosi: Ok, so why don't we bring them over? That's exactly what we did. 249 00:24:22,419 --> 00:24:30,660 Ignazio Graziosi: And this is called importation biological control, where you go there, you study the 250 00:24:30,720 --> 00:24:36,700 Ignazio Graziosi: natural enemies that are effective in native range, and you bring them over. 251 00:24:37,039 --> 00:24:42,980 Ignazio Graziosi: USDA did that after risk assessment and introduced few different species. 252 00:24:43,559 --> 00:24:45,960 Ignazio Graziosi: And you see here three tiny wasps. 253 00:24:47,120 --> 00:24:51,900 Ignazio Graziosi: And those wasps are parasitic wasps or parasitoids. 254 00:24:52,500 --> 00:24:59,220 Ignazio Graziosi: The first two, the one on the left and the one on the center, they attack the larvae of the EAB. 255 00:24:59,880 --> 00:25:02,560 Ignazio Graziosi: The one on the right attacks the eggs. 256 00:25:03,130 --> 00:25:05,160 Ignazio Graziosi: And those are specialists. 257 00:25:05,919 --> 00:25:09,419 Ignazio Graziosi: What it means is that they only attack the EAB. 258 00:25:09,570 --> 00:25:11,919 Ignazio Graziosi: They don't attack any other insect. 259 00:25:12,289 --> 00:25:18,100 Ignazio Graziosi: And so this warrants success in a way, 260 00:25:18,270 --> 00:25:25,780 Ignazio Graziosi: because they cannot start attacking another insect and kind of waste their potential. 261 00:25:26,460 --> 00:25:27,559 Ignazio Graziosi: How do they work? 262 00:25:28,820 --> 00:25:33,179 Ignazio Graziosi: Okay, let's start with the first one here, the one on the left. 263 00:25:33,720 --> 00:25:38,900 Ignazio Graziosi: And you see it's a small wasp and has a kind of a long tail. 264 00:25:39,200 --> 00:25:50,160 Ignazio Graziosi: Its tail is an ovipositor, and it uses its ovipositor to find trees that are infested with the EAB and drill through the bark 265 00:25:50,760 --> 00:25:58,180 Ignazio Graziosi: is able to use vibrational cues to understand if there is a larva under the bark and exactly where it is, 266 00:25:58,940 --> 00:26:09,300 Ignazio Graziosi: and it stings the larvae of the EAB and it puts its own eggs in the larvae. 267 00:26:09,919 --> 00:26:16,500 Ignazio Graziosi: Think about the movie Alien, Alien 1, not Alien 3, because the life cycle in Alien 3 268 00:26:16,510 --> 00:26:20,660 Ignazio Graziosi: gets very complicated, but in Alien 1 is exactly how it works. 269 00:26:21,429 --> 00:26:27,039 Ignazio Graziosi: Inside, there will be the larvae of the wasp that feeds in the body of the larvae of the 270 00:26:27,179 --> 00:26:31,100 Ignazio Graziosi: EAB, eventually consuming the whole animal. 271 00:26:32,139 --> 00:26:36,980 Ignazio Graziosi: The infographic that you see on the slide is the technology that is used to release it. 272 00:26:37,519 --> 00:26:44,320 Ignazio Graziosi: This is a log prepared in the lab that is filled with larvae of the EAB infested with 273 00:26:44,480 --> 00:26:45,820 Ignazio Graziosi: the parasitoid wasp. 274 00:26:46,299 --> 00:26:52,600 Ignazio Graziosi: You hang them on a tree, the wasp, the adult wasp, they will eventually fly out and find 275 00:26:52,880 --> 00:26:57,580 Ignazio Graziosi: other trees infested with the EAB to be parasitized. 276 00:26:58,400 --> 00:27:06,740 Ignazio Graziosi: The second one is the egg parasitoid. I think you know the story now. It works exactly the same way that it attacks eggs. 277 00:27:07,120 --> 00:27:18,420 Ignazio Graziosi: The technology is a small container. You can see in the picture on the bottom right here is a drug container, drugstore container, is called the O-binator. 278 00:27:19,080 --> 00:27:29,800 Ignazio Graziosi: It contains a paper where there are eggs of the EAB that have been parasitized with this parasitic wasp. 279 00:27:30,100 --> 00:27:32,660 Ignazio Graziosi: Look now at the picture in the center. 280 00:27:33,380 --> 00:27:36,560 Ignazio Graziosi: These brown circles are the eggs of the EAB. 281 00:27:36,840 --> 00:27:44,600 Ignazio Graziosi: If you look at the one on the bottom, you can see that inside there is actually a tiny baby larvae of the EAB. 282 00:27:45,460 --> 00:27:52,760 Ignazio Graziosi: that is waiting to hatch. But if you look at the other two, the dark ones, you see that 283 00:27:52,950 --> 00:28:00,679 Ignazio Graziosi: inside there is something different. That is the wasp that is ready to emerge. Okay, 284 00:28:01,360 --> 00:28:06,380 Ignazio Graziosi: So we understand about biological control now, the importation of biological control, 285 00:28:06,779 --> 00:28:09,860 Ignazio Graziosi: but you may ask, "Okay, so we are in North America. 286 00:28:10,720 --> 00:28:14,500 Ignazio Graziosi: What about our native natural enemies?" 287 00:28:14,820 --> 00:28:17,700 Ignazio Graziosi: The answer is, "Yes, we have some." 288 00:28:17,799 --> 00:28:25,399 Ignazio Graziosi: There are many species that have been described of parasitic wasps or other types of insects, 289 00:28:26,240 --> 00:28:28,220 Ignazio Graziosi: but those are not specialists. 290 00:28:28,700 --> 00:28:31,480 Ignazio Graziosi: They can attack also other types of insects. 291 00:28:31,799 --> 00:28:39,360 Ignazio Graziosi: So they are not effective in providing, they cannot be the only ones that can provide control. 292 00:28:40,000 --> 00:28:42,440 Ignazio Graziosi: Alone, they are not enough. 293 00:28:44,880 --> 00:29:01,500 Ignazio Graziosi: So, at the end of the story, what we want to reach for the EAB, and in general for many non-native pests attacking native trees, is balance between the susceptibility of the plant. 294 00:29:03,800 --> 00:29:11,040 Ignazio Graziosi: and the community of natural enemies, both native natural enemies and also biological control. 295 00:29:11,700 --> 00:29:19,520 Ignazio Graziosi: But also in the picture there is also the chemical protection that is really important, especially to save 296 00:29:19,860 --> 00:29:26,280 Ignazio Graziosi: trees of great value. Because it's true that biological control in North America for the 297 00:29:26,300 --> 00:29:35,460 Ignazio Graziosi: EAB hasn't been fully successful yet, but we can still save large trees of big value 298 00:29:35,840 --> 00:29:40,300 Ignazio Graziosi: in the city and the landscape using chemical protection. 299 00:29:42,419 --> 00:29:50,899 Ignazio Graziosi: Okay, so we are ready for our second example, a non-native tree that is attacked by a non-native pest. 300 00:29:51,149 --> 00:29:59,760 Ignazio Graziosi: And this is an example that may be relevant for us in the south, which is the crapemyrtle bark scale. 301 00:30:00,600 --> 00:30:08,399 Ignazio Graziosi: So the crapemyrtle bark scale, you can see here in the center, is of course a non-native 302 00:30:08,620 --> 00:30:12,559 Ignazio Graziosi: scale attacking our beloved crapemyrtle. 303 00:30:13,929 --> 00:30:20,539 Ignazio Graziosi: There is a huge crapemyrtle culture in the south, there are hundreds I think of different 304 00:30:22,120 --> 00:30:29,920 Ignazio Graziosi: belonging to different species is not only Lagerstroemia indica, but there are hybrid of different species, 305 00:30:30,710 --> 00:30:39,320 Ignazio Graziosi: different color, flower, texture of the bark, size, and of course, it's easy to be judgmental 306 00:30:39,940 --> 00:30:47,600 Ignazio Graziosi: toward the crapemyrtle because it's so commonly used and you can say it's used too much. 307 00:30:47,980 --> 00:30:48,419 Ignazio Graziosi: It's true. 308 00:30:49,019 --> 00:30:53,580 Ignazio Graziosi: It's easy to be judgmental, but it's important to remember a couple of things. 309 00:30:54,059 --> 00:30:58,720 Ignazio Graziosi: One is that crapemyrtle, they provide benefits. 310 00:30:59,260 --> 00:31:05,000 Ignazio Graziosi: And you can see here a little report that has been prepared using this tool called iTree. 311 00:31:05,700 --> 00:31:14,140 Ignazio Graziosi: If you are not familiar with the iTree, it is a suite of different tools that can be extremely useful to calculate benefits, 312 00:31:15,020 --> 00:31:23,940 Ignazio Graziosi: so-called ecosystem services of trees, but also can be used to select the right tree for the right place. 313 00:31:24,940 --> 00:31:39,600 Ignazio Graziosi: The second reason is that regardless of how much the crapemyrtle is planted in the south, we have to deal with this pest because it will create damage. 314 00:31:39,760 --> 00:31:46,900 Ignazio Graziosi: We will have to deal with removal of attack trees or the control of the pest itself. 315 00:31:47,760 --> 00:31:52,700 Ignazio Graziosi: Okay, so the crapemyrtle bark scale, starting from the picture on the left. 316 00:31:53,059 --> 00:31:59,460 Ignazio Graziosi: This is a twig of a crapemyrtle, of course you see the white specks, those are individual, 317 00:32:00,260 --> 00:32:09,940 Ignazio Graziosi: mostly female of the crapemyrtle bark scale, CMBS in short. Why is black? Because like aphids, 318 00:32:10,480 --> 00:32:18,059 Ignazio Graziosi: Of course, scale, while they feed, they secrete droplets of sugary sap. 319 00:32:18,750 --> 00:32:23,159 Ignazio Graziosi: And so black sooty molds, they grow on that. 320 00:32:23,730 --> 00:32:27,179 Ignazio Graziosi: On the picture in the center, different things. 321 00:32:27,820 --> 00:32:34,159 Ignazio Graziosi: Those white lumps are mostly mature females of the scale, 322 00:32:34,450 --> 00:32:38,580 Ignazio Graziosi: but you can also see here immature female nymphs. 323 00:32:39,100 --> 00:32:42,179 Ignazio Graziosi: And this is important for the life cycle. 324 00:32:42,380 --> 00:32:48,679 Ignazio Graziosi: On the right you see a female and if you flip the female you see the eggs. 325 00:32:49,100 --> 00:32:53,559 Ignazio Graziosi: Those very nice pink color are eggs. 326 00:32:55,860 --> 00:33:09,580 Ignazio Graziosi: The life cycle involves both males and females. The male is actually winged, the female is not winged, and a mature female lose legs and cannot move. 327 00:33:10,580 --> 00:33:28,559 Ignazio Graziosi: One of the things complicated the control is that it's not clear how many generations there are. They describe up to five generations, but the problem is that they are overlapping. So at one point, at any point, you may find different stages of the insect. 328 00:33:28,640 --> 00:33:36,640 Ignazio Graziosi: If I go back one slide, the picture in the middle here has been shot one month ago in Athens, 329 00:33:37,520 --> 00:33:44,600 Ignazio Graziosi: so in the winter. And you can see there are nymphs and adults. The nymphs are called crawlers. 330 00:33:46,000 --> 00:33:47,520 Ignazio Graziosi: Okay, what is the situation? 331 00:33:47,900 --> 00:33:56,220 Ignazio Graziosi: Was found in 2004 in Texas, of course huge crapemyrtle culture state, and then in 2014 332 00:33:56,620 --> 00:34:03,020 Ignazio Graziosi: in Georgia, and only in 2018, unfortunately, was found in nursery in Georgia. 333 00:34:03,580 --> 00:34:09,920 Ignazio Graziosi: The QR code I put there is a summary of the status and the biology of the crapemyrtle 334 00:34:09,920 --> 00:34:12,020 Ignazio Graziosi: bark scale from UGA. 335 00:34:13,100 --> 00:34:15,420 Ignazio Graziosi: So if you are interested, please snatch that. 336 00:34:17,780 --> 00:34:24,240 Ignazio Graziosi: Okay, so we already know the invasion curve, what it means, and it's really important for 337 00:34:24,460 --> 00:34:28,660 Ignazio Graziosi: the crapemyrtle bark scale, even though it's already present in the south, even though it's already 338 00:34:28,860 --> 00:34:33,360 Ignazio Graziosi: present in Georgia, to be able to detect it as soon as possible. 339 00:34:34,040 --> 00:34:35,400 Ignazio Graziosi: It's not everywhere yet. 340 00:34:35,680 --> 00:34:38,340 Ignazio Graziosi: In Athens, it got there, I think, in 2021. 341 00:34:39,740 --> 00:34:46,360 Ignazio Graziosi: And you can see it in high numbering for some trees, but there are a lot of trees. 342 00:34:46,450 --> 00:34:48,040 Ignazio Graziosi: They have a very low infestation. 343 00:34:48,130 --> 00:34:54,480 Ignazio Graziosi: So I would say we are at the beginning of the invasion in a lot of places in Georgia. 344 00:34:55,000 --> 00:35:01,440 Ignazio Graziosi: So we are in the situation where we can do well because we are at the point on the invasion 345 00:35:01,880 --> 00:35:02,020 Ignazio Graziosi: curve. 346 00:35:02,400 --> 00:35:09,380 Ignazio Graziosi: where the population is not so high again, that our control can mean something. 347 00:35:10,400 --> 00:35:14,020 Ignazio Graziosi: Alrighty, let's go back to our well-known map. 348 00:35:14,490 --> 00:35:19,740 Ignazio Graziosi: So we know that it is a non-native, come from Asia. 349 00:35:20,660 --> 00:35:24,220 Ignazio Graziosi: So we may ask, "Okay, what about the host there?" 350 00:35:24,940 --> 00:35:33,140 Ignazio Graziosi: The bad news is that this insect in native Asia can feed on many different species of plant. 351 00:35:33,480 --> 00:35:40,520 Ignazio Graziosi: It's not a specialist, so it can feed on apple in Asia, and soybean has been found on fig. 352 00:35:41,000 --> 00:35:52,760 Ignazio Graziosi: One good news is that since there are so many, so they were able to find some cultivar, some species of crapemyrtle that has a low susceptibility. 353 00:35:53,000 --> 00:35:59,220 Ignazio Graziosi: And for example, the species Lagerstroemia speciosa, they are studying these still, though. 354 00:36:01,160 --> 00:36:03,799 Ignazio Graziosi: Okay, so those are the plants in Asia. 355 00:36:04,020 --> 00:36:05,880 Ignazio Graziosi: What about the plants in North America? 356 00:36:06,339 --> 00:36:12,039 Ignazio Graziosi: We know that it attacks basically most of the cultivar of the crapemyrtle, but unfortunately, 357 00:36:13,200 --> 00:36:20,960 Ignazio Graziosi: like the EAB was able to find the white fringetree, the crapemyrtle bark scale started to 358 00:36:21,140 --> 00:36:26,299 Ignazio Graziosi: feed happily on American beautyberry and also on St. John's wort. 359 00:36:27,120 --> 00:36:35,060 Ignazio Graziosi: So, this can be a problem, of course, because it can go around attacking other plant. 360 00:36:35,430 --> 00:36:41,320 Ignazio Graziosi: Okay, we are familiar with the disease triangle, so we may ask, okay, what about the role of 361 00:36:41,320 --> 00:36:41,920 Ignazio Graziosi: the environment? 362 00:36:42,240 --> 00:36:43,940 Ignazio Graziosi: What is the role of the environment here? 363 00:36:45,400 --> 00:36:56,900 Ignazio Graziosi: Unfortunately, again, scales are one of the group of insects that most take advantage of urban heat island. 364 00:36:57,200 --> 00:37:05,039 Ignazio Graziosi: Urban heat island, of course, is the phenomenon that causes temperature due to hardscape in the city to be even 10 degrees higher. 365 00:37:05,660 --> 00:37:07,099 Ignazio Graziosi: And this has two effects. 366 00:37:08,240 --> 00:37:13,440 Ignazio Graziosi: First of all, it stresses trees and they become more susceptible to pests. 367 00:37:13,920 --> 00:37:17,360 Ignazio Graziosi: Second, it accelerates the development of the insect itself. 368 00:37:17,950 --> 00:37:21,360 Ignazio Graziosi: And scales are very good in taking advantage of that. 369 00:37:22,700 --> 00:37:28,200 Ignazio Graziosi: OK, let's go to some good news, the tools, the weapons we have to control it. 370 00:37:28,600 --> 00:37:35,460 Ignazio Graziosi: So this is an overview, again, of the chemical control available for the crapemyrtle bark 371 00:37:35,660 --> 00:37:35,960 Ignazio Graziosi: scale. 372 00:37:36,200 --> 00:37:44,680 Ignazio Graziosi: We have soil drench, we have soil injection, we have foliar sprays, and also some soaps 373 00:37:44,860 --> 00:37:52,980 Ignazio Graziosi: they can be used mostly to target crawlers, which again are the small, the young nymphs, 374 00:37:53,300 --> 00:37:57,060 Ignazio Graziosi: like the one, the pinkish one in the photo here. 375 00:37:57,740 --> 00:38:05,680 Ignazio Graziosi: Okay, you can see in the table different product brand names and how they can be applied. 376 00:38:06,220 --> 00:38:13,000 Ignazio Graziosi: And I encourage you again to snatch that QR code because we'll give you the full protocol 377 00:38:13,160 --> 00:38:14,260 Ignazio Graziosi: that you can use. 378 00:38:14,600 --> 00:38:20,300 Ignazio Graziosi: The control, the chemical control is complicated by the fact that crapemyrtle is not good in 379 00:38:20,880 --> 00:38:24,500 Ignazio Graziosi: absorbing systemic insecticide through trunk injection. 380 00:38:25,180 --> 00:38:29,780 Ignazio Graziosi: The chemical moves very slowly, so that is not a viable option, unfortunately. 381 00:38:31,600 --> 00:38:37,500 Ignazio Graziosi: Okay, we know about natural enemies, so we may ask now, looking at our map, what is the 382 00:38:37,720 --> 00:38:39,280 Ignazio Graziosi: situation for this pest? 383 00:38:39,680 --> 00:38:46,680 Ignazio Graziosi: Yes, in Asia, there is a healthy community of predators and parasitic wasps that worldwide 384 00:38:47,060 --> 00:38:48,720 Ignazio Graziosi: and in Asia can attack. 385 00:38:48,820 --> 00:38:56,360 Ignazio Graziosi: In the US, they were not able yet to clearly find an effective parasitoids, but there are 386 00:38:56,560 --> 00:39:03,220 Ignazio Graziosi: many predators that can feed on the crapemyrtle bark scale, and they are used to try to control 387 00:39:03,680 --> 00:39:03,780 Ignazio Graziosi: it. 388 00:39:04,420 --> 00:39:07,540 Ignazio Graziosi: So, this is another question for you. 389 00:39:08,200 --> 00:39:12,500 Ignazio Graziosi: If you know what is this, please write it in the chat box. 390 00:39:15,780 --> 00:39:24,160 Ignazio Graziosi: Okay, so those are eggs of lady beetles, because lady beetles, different species of lady beetles, 391 00:39:24,400 --> 00:39:29,860 Ignazio Graziosi: are avid, hungry predators of the crapemyrtle bark scale. 392 00:39:30,090 --> 00:39:36,740 Ignazio Graziosi: There are three main species: the twice-stabbed lady beetle, the bigeminal, sorry, 393 00:39:37,480 --> 00:39:43,800 Ignazio Graziosi: The bigeminal lady beetle, which looks like the twice-stabbed, but is a completely different species 394 00:39:44,280 --> 00:39:48,560 Ignazio Graziosi: and also the non-native Harlequin lady beetle. 395 00:39:48,900 --> 00:39:56,800 Ignazio Graziosi: These species, they will find trees infested with the crapemyrtle bark scale and they will feed on nymphs and adults alike. 396 00:39:59,020 --> 00:40:06,400 Ignazio Graziosi: So, they help, yes, they do help, but often they arrive too late in the season and they 397 00:40:06,470 --> 00:40:07,640 Ignazio Graziosi: are not specialists. 398 00:40:07,730 --> 00:40:15,220 Ignazio Graziosi: They will feed on other prey, which means they will not stay for many generations on 399 00:40:15,220 --> 00:40:22,300 Ignazio Graziosi: the tree, providing continuous control, and that is a problem. 400 00:40:23,020 --> 00:40:28,339 Ignazio Graziosi: So this is my last question for you, if you have any idea of what is this. 401 00:40:30,550 --> 00:40:39,640 Ignazio Graziosi: This of course is an egg from another predator that would happily feed on the crapemyrtle bark scale. 402 00:40:40,320 --> 00:40:42,700 Ignazio Graziosi: It's called stalked egg. 403 00:40:43,520 --> 00:40:47,060 Ignazio Graziosi: This is a beautiful egg of lacewings. 404 00:40:47,900 --> 00:40:56,280 Ignazio Graziosi: One species in particular, the red-lipped, green lacewing, it feeds and predates on crapemyrtle 405 00:40:56,460 --> 00:40:59,460 Ignazio Graziosi: bark scale nymphs and eggs as well. 406 00:40:59,960 --> 00:41:08,940 Ignazio Graziosi: And you can see on the sequence on the right, this is a larvae of the lacewing, which are 407 00:41:08,940 --> 00:41:09,800 Ignazio Graziosi: the most voracious. 408 00:41:11,640 --> 00:41:16,859 Ignazio Graziosi: They swing. Do they work? Yes, they are actually available commercially, of course, to control 409 00:41:17,299 --> 00:41:23,339 Ignazio Graziosi: different pests, including CMBS. But the problem is they don't build up a population on the 410 00:41:23,359 --> 00:41:29,720 Ignazio Graziosi: plant like the previous case. And also adults need to feed on. 411 00:41:30,640 --> 00:41:37,440 Ignazio Graziosi: sugar. And this means that you have to continuously, through the season, release. 412 00:41:38,220 --> 00:41:43,220 Ignazio Graziosi: So, just one release at the beginning of the season is not enough. 413 00:41:44,560 --> 00:41:48,640 Ignazio Graziosi: But they are commercially available and they can be used. 414 00:41:48,980 --> 00:41:55,100 Ignazio Graziosi: Of course, you need to do chemical control very carefully because it has a potential to 415 00:41:55,580 --> 00:41:58,500 Ignazio Graziosi: infuriate the biological control. 416 00:41:58,900 --> 00:42:03,940 Ignazio Graziosi: At the same way as for the EAB, what we want in the future is a balance. 417 00:42:04,150 --> 00:42:11,440 Ignazio Graziosi: We want the population of the scale low because the community of natural enemy is healthy, 418 00:42:11,980 --> 00:42:19,520 Ignazio Graziosi: but we want to use and we want to do additional research to find effective chemical control 419 00:42:20,000 --> 00:42:23,859 Ignazio Graziosi: that maybe is more compatible with the natural enemy. 420 00:42:25,040 --> 00:42:37,320 Ignazio Graziosi: Okay, this brings me to the last, I would say, five, eight minutes, which is the last story in my presentation, which is a native tree impacted by native pests. 421 00:42:37,370 --> 00:42:42,460 Ignazio Graziosi: And our example is the orange-striped oakworm moth. 422 00:42:43,320 --> 00:42:52,300 Ignazio Graziosi: So this, of course, is a very well-known pest of oaks, especially red oaks in the group of the red 423 00:42:52,480 --> 00:42:58,900 Ignazio Graziosi: oaks, but can feed on other plants, including hickory, birch, and maple. On the left, 424 00:42:59,440 --> 00:43:07,040 Ignazio Graziosi: It's interesting because you can see that the skeletonizing damage is the one that is done by the baby larvae after hatching. 425 00:43:07,380 --> 00:43:12,220 Ignazio Graziosi: And then as they grow, they start feeding on the entirety of the leaf lamina. 426 00:43:13,540 --> 00:43:23,060 Ignazio Graziosi: And in some case, extreme case, especially for small trees, they can completely strip a tree. 427 00:43:23,860 --> 00:43:28,020 Ignazio Graziosi: And this tree, the four on the right, is in early August. 428 00:43:29,240 --> 00:43:31,840 Ignazio Graziosi: And it's a young, but not super young tree. 429 00:43:32,240 --> 00:43:35,180 Ignazio Graziosi: It's a willow oak that was completely defoliated. 430 00:43:36,040 --> 00:43:41,880 Ignazio Graziosi: OK, a little summary, I know a lot of you are already familiar with it, is of course 431 00:43:41,920 --> 00:43:51,480 Ignazio Graziosi: a late summer and fall season pest that offers winter as a pupa and produces in the south 432 00:43:51,680 --> 00:43:53,020 Ignazio Graziosi: two generations per year. 433 00:43:53,960 --> 00:43:55,180 Ignazio Graziosi: So, we can start here. 434 00:43:55,740 --> 00:44:02,040 Ignazio Graziosi: The adults they mate and the female lay eggs here on the underside of leaves in the late 435 00:44:02,380 --> 00:44:02,580 Ignazio Graziosi: summer. 436 00:44:03,040 --> 00:44:10,640 Ignazio Graziosi: And then young larvae, it initially feeds all together on the same branch where they 437 00:44:10,800 --> 00:44:11,220 Ignazio Graziosi: hatched. 438 00:44:11,400 --> 00:44:16,680 Ignazio Graziosi: And then as they grow, they disperse a little bit because they need a lot of leaves. 439 00:44:17,720 --> 00:44:31,740 Ignazio Graziosi: And then again, they can defoliate. In some cases, they can defoliate completely a tree, but those cases are quite rare and exclusively for small trees. And at the end of the season, 440 00:44:32,700 --> 00:44:40,120 Ignazio Graziosi: After, for example, for the south, the second generation is complete in the fall with the 441 00:44:40,300 --> 00:44:47,720 Ignazio Graziosi: first cold, the larvae they drop to the ground and they will pupate in the first five inch 442 00:44:47,990 --> 00:44:48,580 Ignazio Graziosi: in the ground. 443 00:44:51,200 --> 00:44:57,740 Ignazio Graziosi: Okay, so we can use our map as a tool to ask questions. 444 00:44:58,240 --> 00:44:59,620 Ignazio Graziosi: Okay, it's a native pest. 445 00:45:00,180 --> 00:45:02,980 Ignazio Graziosi: Why it causes or can cause so much damage? 446 00:45:03,300 --> 00:45:04,760 Ignazio Graziosi: What about the plant? 447 00:45:05,000 --> 00:45:10,820 Ignazio Graziosi: What about the other factor we looked together earlier for the other two pests? 448 00:45:11,380 --> 00:45:18,760 Ignazio Graziosi: First of all, of course, is a pest of particular relevance for urban and landscape trees and young trees. 449 00:45:19,220 --> 00:45:19,400 Ignazio Graziosi: Why? 450 00:45:20,520 --> 00:45:22,340 Ignazio Graziosi: Remembering this triangle. 451 00:45:23,400 --> 00:45:26,040 Ignazio Graziosi: What is the role of the plant? This is an example. 452 00:45:26,230 --> 00:45:31,600 Ignazio Graziosi: A lot of the trees in urban environment are trees that come from the nursery, 453 00:45:32,110 --> 00:45:34,720 Ignazio Graziosi: and so are often clonal trees. 454 00:45:35,240 --> 00:45:38,700 Ignazio Graziosi: The genetic variability of those trees are very low. 455 00:45:39,030 --> 00:45:39,880 Ignazio Graziosi: For example, 456 00:45:40,660 --> 00:45:45,960 Ignazio Graziosi: An example, on a UGA campus in Athens, there are a lot of beautiful Nuttall oaks. 457 00:45:46,650 --> 00:45:54,880 Ignazio Graziosi: But those, they come from, they are very high quality trees, but they are basically the same tree. 458 00:45:55,779 --> 00:45:57,799 Ignazio Graziosi: And so the susceptibility is low. 459 00:45:58,470 --> 00:46:02,599 Ignazio Graziosi: One tree means the susceptibility for all the trees on campus of the... 460 00:46:03,020 --> 00:46:04,680 Ignazio Graziosi: Nuttall oak is low. 461 00:46:05,160 --> 00:46:10,240 Ignazio Graziosi: And so they are heavily attacked by the orange-striped oakworm moth. 462 00:46:11,780 --> 00:46:13,200 Ignazio Graziosi: Okay, what about the environment? 463 00:46:13,600 --> 00:46:19,700 Ignazio Graziosi: An example, again, yes, in urban environment, we have the problem of heat. 464 00:46:20,280 --> 00:46:29,540 Ignazio Graziosi: Again, and we know that we'll stress trees, but we'll help the development of the orange-striped oakworm moth as well. 465 00:46:30,279 --> 00:46:35,160 Ignazio Graziosi: These are some of the reasons why it can be a pest. 466 00:46:35,400 --> 00:46:36,839 Ignazio Graziosi: Okay, what about natural enemies? 467 00:46:37,059 --> 00:46:40,940 Ignazio Graziosi: So right now we know all the questions we should ask. 468 00:46:41,400 --> 00:46:44,520 Ignazio Graziosi: Yes, there are natural enemies that are being described. 469 00:46:44,940 --> 00:46:46,400 Ignazio Graziosi: We know of them. 470 00:46:46,599 --> 00:46:55,039 Ignazio Graziosi: There are various predators that feed on larvae, for example, yellow jackets and other wasps. 471 00:46:55,260 --> 00:47:05,079 Ignazio Graziosi: There are various parasitoids and fungal disease that kill the pupae up to 10 or in some case 20% of the pupae. 472 00:47:05,300 --> 00:47:07,920 Ignazio Graziosi: And there are a lot of parasitoids that parasitize the eggs. 473 00:47:08,560 --> 00:47:14,839 Ignazio Graziosi: And it's important, this is an example. On the picture on the left, this is the underside of 474 00:47:16,300 --> 00:47:19,720 Ignazio Graziosi: pinnacle leaf full of eggs from the orange-striped 475 00:47:20,040 --> 00:47:24,900 Ignazio Graziosi: oakworm moth. But if we look closely, we see that some of those eggs are yellow. 476 00:47:25,700 --> 00:47:32,520 Ignazio Graziosi: Those eggs are empty eggs. You can see the opening here on the side. They open like a wallet. 477 00:47:33,240 --> 00:47:36,420 Ignazio Graziosi: and the baby larvae already came out, so they hatched. 478 00:47:36,720 --> 00:47:42,020 Ignazio Graziosi: But some other eggs, you can see this one, for example, the dark ones, 479 00:47:42,460 --> 00:47:47,740 Ignazio Graziosi: they have circular openings. That means it has been parasitized. 480 00:47:48,390 --> 00:47:55,799 Ignazio Graziosi: So that is a parasitoid, that is an egg parasitoid, a wasp that emerged from that egg. 481 00:47:56,540 --> 00:48:04,740 Ignazio Graziosi: Okay, let's talk about control. So since this pest can be a pest but in some cases the damage is not so high, 482 00:48:05,130 --> 00:48:07,780 Ignazio Graziosi: it's important to understand the need for the control. 483 00:48:08,540 --> 00:48:14,320 Ignazio Graziosi: First of all, we need to distinguish between aesthetic damage and actual damage for the plant. 484 00:48:14,900 --> 00:48:22,600 Ignazio Graziosi: The threshold is around 25% of defoliation. And then we need to assess the season. 485 00:48:23,200 --> 00:48:41,319 Ignazio Graziosi: Why? Because late defoliation, even if it's a very substantial defoliation, but occurs late in the season, is not really harmful to the tree, because the tree already stores all the nutrients, and so it's not very harmful. So it's important to kind of judge. 486 00:48:42,000 --> 00:48:44,060 Ignazio Graziosi: the severity of the situation. 487 00:48:44,660 --> 00:48:45,960 Ignazio Graziosi: What can we use, though? 488 00:48:46,320 --> 00:48:49,300 Ignazio Graziosi: So we can use Btk, Bacillus thuringiensis 489 00:48:49,740 --> 00:48:51,520 Ignazio Graziosi: kurstaki, as a foliar spray, 490 00:48:52,160 --> 00:48:53,040 Ignazio Graziosi: which is effective, 491 00:48:53,700 --> 00:48:56,500 Ignazio Graziosi: but mostly on young instar, of course, 492 00:48:56,660 --> 00:48:58,860 Ignazio Graziosi: on young larvae, 493 00:48:59,100 --> 00:49:01,520 Ignazio Graziosi: has a very little impact on natural enemy, 494 00:49:01,580 --> 00:49:02,360 Ignazio Graziosi: which is good, 495 00:49:02,800 --> 00:49:04,660 Ignazio Graziosi: but often needs to be reapplied. 496 00:49:04,720 --> 00:49:09,900 Ignazio Graziosi: But there are also other options for contact and also systemic insecticides. 497 00:49:10,430 --> 00:49:18,200 Ignazio Graziosi: I encourage you also here to take a look at the publication link to the QR code here if 498 00:49:18,200 --> 00:49:19,180 Ignazio Graziosi: you are interested. 499 00:49:19,710 --> 00:49:24,480 Ignazio Graziosi: With that, I came to the end of my presentation. 500 00:49:25,320 --> 00:49:43,380 Ignazio Graziosi: And I hope I will be able to provide you some insight on what are the biological parameters and the ecological interaction you have to look at to understand what is the damage and the control that can be applied to a pest. 501 00:49:43,900 --> 00:49:52,440 Ignazio Graziosi: With that, I think I will stop my sharing and I will take any question you may have. 502 00:49:53,099 --> 00:49:59,460 Ignazio Graziosi: And I will ask your help, Bodie, to summarize any question that came. 503 00:50:01,100 --> 00:50:06,180 Bodie Pennisi: Thank you, Ignazio. That was great. Lots of really, really excellent information. 504 00:50:06,900 --> 00:50:13,220 Bodie Pennisi: There hasn't been a question in the chat. There's lots of really good comments. Thank you. 505 00:50:13,600 --> 00:50:20,600 Bodie Pennisi: I do want to mention something. When you were talking about the crapemyrtle bark scale, 506 00:50:21,160 --> 00:50:29,400 Bodie Pennisi: unfortunately I have seen much expansion of the pest in landscapes, especially new landscapes, but even established 507 00:50:28,579 --> 00:50:29,440 Bodie Pennisi: I 508 00:50:29,420 --> 00:50:37,539 Bodie Pennisi: landscapes. I mean, I was in Savannah last year, same tree. At that height, there was no evidence. 509 00:50:37,730 --> 00:50:43,140 Bodie Pennisi: I mean, again, the tree was pretty high. But this year, we were just there like two weeks ago, 510 00:50:43,640 --> 00:50:49,740 Bodie Pennisi: and it was right there. And, you know, it was a large tree too. And all across the areas around 511 00:50:49,920 --> 00:50:57,160 Bodie Pennisi: the planet, I have visited pretty much, I would say maybe about 60-70% of plantings have evidence. 512 00:50:57,880 --> 00:51:01,040 Bodie Pennisi: So yeah, it's pretty bad. 513 00:51:04,320 --> 00:51:07,220 Bodie Pennisi: Yeah, we just have lots of really happy people. 514 00:51:07,349 --> 00:51:08,700 Bodie Pennisi: So thank you so much again. 515 00:51:08,710 --> 00:51:10,680 Bodie Pennisi: I know you stayed late to entertain us 516 00:51:10,900 --> 00:51:13,500 Bodie Pennisi: and share with us your expertise and knowledge. 517 00:51:13,800 --> 00:51:15,320 Bodie Pennisi: So have fun, be safe, 518 00:51:15,540 --> 00:51:18,579 Bodie Pennisi: and have a safe trip back to the U.S. 519 00:51:19,660 --> 00:51:26,320 Ignazio Graziosi: Thank you, Bodie. It was my pleasure. I really enjoyed it. And yeah, I'm looking forward to being in touch. 520 00:51:27,240 --> 00:51:28,080 Ignazio Graziosi: Thank you. Bye-bye. 521 00:51:28,960 --> 00:51:29,700 Ignazio Graziosi: Thank you. Bye-bye. 522 00:51:33,100 --> 00:51:38,220 Rich Braman: All right, everybody. Thanks for joining us again for the first one of these of this year. 523 00:51:39,079 --> 00:51:41,020 Rich Braman: And we'll see everyone in March. 524 00:51:41,940 --> 00:51:47,960 Rich Braman: And just make sure you get your sign-in sheets to us at gtbop at uga.edu. 525 00:51:48,770 --> 00:51:52,980 Rich Braman: And if you need to mail those to us, you'll find that mailing address at the top of the sign-in sheet. 526 00:51:56,160 --> 00:51:57,380 Rich Braman: I think that's it for me, Bodie. 527 00:51:57,380 --> 00:51:57,780 Bodie Pennisi: Thank you, Richie. 528 00:52:00,880 --> 00:52:10,340 Rich Braman: I'm going to hang around for just a minute to make sure we don't have any procedural questions, but I'll see you soon, buddy. 529 00:52:11,040 --> 00:52:11,580 Bodie Pennisi: All righty.