1 00:00:00,330 --> 00:00:05,640 Hello, my name's Lindsay Turnbull and I'm an associate professor in the Department of Plant Sciences 2 00:00:05,640 --> 00:00:10,770 at the University of Oxford, and we're right in the middle of this very serious corona virus crisis right 3 00:00:10,770 --> 00:00:15,780 now. And my students are all stuck at home and we want to keep them in touch with biology 4 00:00:15,780 --> 00:00:20,790 and keep in touch with us. And so we're going to make a new series of videos and they're going to be called back 5 00:00:20,790 --> 00:00:46,680 garden biology. 6 00:00:46,680 --> 00:00:52,890 Hello, welcome to this episode. Back on Biology, and today we're going to be looking at moths 7 00:00:52,890 --> 00:00:57,900 now Multa, one of those groups of insects that most people don't know a lot about. And part of 8 00:00:57,900 --> 00:01:02,910 the reason for that is that a lot of moths are nocturnal. So the adults anyway, we don't see 9 00:01:02,910 --> 00:01:08,550 them around flying during the day very often, but also kind of unsung heroes. 10 00:01:08,550 --> 00:01:13,800 They're actually really important pollinators for lots of plants. We just don't see them doing it. 11 00:01:13,800 --> 00:01:19,270 We see the bees, but we don't see the moths. That doesn't mean that they're not important. 12 00:01:19,270 --> 00:01:24,330 Now, if you're a gardener, they're all some moths that you might be familiar with. And sometimes it might 13 00:01:24,330 --> 00:01:29,340 be because you see the caterpillars. So one of the most sort of prominent caterpillars that 14 00:01:29,340 --> 00:01:34,890 you might see in your garden is this. And this belongs to a moth called the Mulan 15 00:01:34,890 --> 00:01:40,380 Moth. And they specialise on eating melons. And their Latin name for Mullan's is for Bascome. 16 00:01:40,380 --> 00:01:46,110 And they're quite common garden plants. So they form a nice rosette. Now, these lovely woolly grey leaves 17 00:01:46,110 --> 00:01:51,870 and then they Boltz and they produce these big flower speiser and yellow flowers and are very popular with gardeners 18 00:01:51,870 --> 00:01:56,940 and may get eaten voraciously by these Moland moth caterpillars. So you may have seen 19 00:01:56,940 --> 00:02:02,040 those in your garden or when you're out and about because Mullin's are wild plants as well. And that 20 00:02:02,040 --> 00:02:07,110 is one of the things I want to emphasise this week as well. I know that not everybody has a garden. I'm very lucky 21 00:02:07,110 --> 00:02:12,270 to have a garden. And when I started this series, obviously, I couldn't go anywhere else because 22 00:02:12,270 --> 00:02:17,550 we were in the really tight lockdown. But we're not doing that anymore. And I want to go out of my garden 23 00:02:17,550 --> 00:02:22,590 a little bit in order to open up this programme to people who do not have a garden. Now, as 24 00:02:22,590 --> 00:02:27,840 well as Meulen moth caterpillars, you might be lucky to find one of these annual garden all wandering 25 00:02:27,840 --> 00:02:32,850 around in the countryside in August. This is an elephant hawk moth caterpillar, and 26 00:02:32,850 --> 00:02:38,880 it's really, really beautiful. And we happened to see one in August last year when we were having a walk in the countryside. 27 00:02:38,880 --> 00:02:44,190 Elephant Hawk moths are spectacular adults as well. That pink and green, there's actually 28 00:02:44,190 --> 00:02:49,620 a common elephant hawk moth and also a small elephant talk mouth. And you can see them here. 29 00:02:49,620 --> 00:02:54,630 And the caterpillars have this extraordinary defence mechanisms. They've got these eye spots and 30 00:02:54,630 --> 00:02:59,750 they can actually swell up and sort of the ideas they're trying to startle predators 31 00:02:59,750 --> 00:03:05,080 and people phone up the wildlife trust every year saying, oh, my goodness, think I'm out of a snake in my garden, 32 00:03:05,080 --> 00:03:10,380 then actually it's just one of these caterpillars. But they are beautiful. They're sort of velvety and smooth and lovely 33 00:03:10,380 --> 00:03:15,720 and handling warm was a really nice experience. Now, this second caterpillar belongs 34 00:03:15,720 --> 00:03:20,730 to the goat moth. And frankly, when we stumbled across this on a footpath, we thought, what the 35 00:03:20,730 --> 00:03:25,740 heck is that? It looks like a giant maggot, not a caterpillar. And it's 36 00:03:25,740 --> 00:03:31,050 a little bit repellent to handle. I did pick it up, but I wanted to move it off the path so it didn't get trodden 37 00:03:31,050 --> 00:03:36,060 on. I mean, I only found out later because I didn't know what it was. When I found that it actually belongs 38 00:03:36,060 --> 00:03:41,430 to quite a ram off the goat moth and it lives inside trees eating 39 00:03:41,430 --> 00:03:46,650 away at wood. So there are actually caterpillars that are wood boring. They don't all 40 00:03:46,650 --> 00:03:52,230 just eat leaves. And there are other kinds of moth that live inside leaves 41 00:03:52,230 --> 00:03:57,960 that are really tiny. I mean, mine leaves from the inside out and are going to do a little piece on that. 42 00:03:57,960 --> 00:04:02,970 So in today's episode, you're going to see four little sections. One is about the leaf mining 43 00:04:02,970 --> 00:04:08,280 activities of a particular caterpillar. One is me going on a hunt for the Hornet 44 00:04:08,280 --> 00:04:13,380 moth. And that is one of the coolest, most amazing, most charismatic moths in Britain. And I'm going 45 00:04:13,380 --> 00:04:18,500 to show you that you can find really cool stuff like that in the most mundane places. 46 00:04:18,500 --> 00:04:24,780 So I'm going to show you how I managed to track that down in my local park literally next to the dog poop. 47 00:04:24,780 --> 00:04:29,880 I'm also going to go and visit Doug Boys, who's a real moth expert, and he's doing his pitch day on moths 48 00:04:29,880 --> 00:04:34,890 out at Y term. And he's going to show us a little bit about what he's doing for his research and how he traps 49 00:04:34,890 --> 00:04:39,950 moths in order to count them and have good records. And finally, we're going to see Ben Sheldon, 50 00:04:39,950 --> 00:04:45,480 who is a professor in the Department of Zoology who runs a moth trap in the back of his garden, a light trap. 51 00:04:45,480 --> 00:04:50,610 And we'll be able to see him, how he sets that up and how he empties out every morning. And we'll be up to find out what 52 00:04:50,610 --> 00:04:56,320 he's been catching. 53 00:04:56,320 --> 00:05:01,360 So I want to begin by talking about a moth called the horse chestnut leaf miner. And if you 54 00:05:01,360 --> 00:05:06,820 pay attention to those chestnut trees, you'll notice that at the moment they're starting to look exceedingly worse for wear. 55 00:05:06,820 --> 00:05:12,040 And that's because the caterpillars of the horse chestnut leaf miner have started to attack 56 00:05:12,040 --> 00:05:17,170 the leaves. And a leaf miner is an insect that lives inside the leaves. 57 00:05:17,170 --> 00:05:22,750 And it's not just moths that are leaf mining. In fact, they're not the communist group. There are various flies, their various beetles 58 00:05:22,750 --> 00:05:28,000 and various moths that all engage in leaf mining. And what they're trying to do is mine 59 00:05:28,000 --> 00:05:33,130 out the good stuff and leaf. So let's have a look at this was chestnut leaf and see what they're doing. So you can see 60 00:05:33,130 --> 00:05:38,560 here's the nice Greenleaf. And here are these are these ugly brown stains 61 00:05:38,560 --> 00:05:43,810 they almost look like. But what's actually happened is an insect has got in. It's eaten out 62 00:05:43,810 --> 00:05:49,540 all of the green cells. So then no longer green and it's peering out the undigested 63 00:05:49,540 --> 00:05:54,910 bits. And that's what all the brown stuff is. So insect poo is called frass. So the minds 64 00:05:54,910 --> 00:06:00,010 are filled with France. And as the year goes on, these holes, chestnut leaves can be almost entirely 65 00:06:00,010 --> 00:06:05,170 destroyed by miners. Now, this moth only arrived in Britain 66 00:06:05,170 --> 00:06:10,510 in 2002. So the horse chestnut itself is an introduced tree. It's not native to Britain, 67 00:06:10,510 --> 00:06:15,610 but for the first couple of hundred years that it was here, it was beautiful and pristine. And I certainly remember that when 68 00:06:15,610 --> 00:06:20,860 I was a kid or even a sort of middle aged 20 years ago or more, that you could see wonderful 69 00:06:20,860 --> 00:06:25,990 horse chestnut trees with perfect, unblemished leaves. But you can't see that anymore. So let's have a look. 70 00:06:25,990 --> 00:06:31,030 It's a cross section of a leaf that was drawn by Pandora. We can see what they're doing. So you 71 00:06:31,030 --> 00:06:36,130 can see this is the cross section of the leaf. This is the upper surface. This is the lower surface. This is the little 72 00:06:36,130 --> 00:06:41,170 hole, the stem after where gas exchange happens. So air moves in 73 00:06:41,170 --> 00:06:46,270 and out of the leaf. And all these leaves have lots of air spaces to allow 74 00:06:46,270 --> 00:06:51,340 the free diffusion of gases and of water vapour. And the veins are here 75 00:06:51,340 --> 00:06:56,530 and the veins are often very tough. So the cells that make up the piping of the leaf 76 00:06:56,530 --> 00:07:01,570 are tough and fibrous and not very digestible. And so the miners avoid all of those. They just 77 00:07:01,570 --> 00:07:06,610 get in and they all these G.S. sounds that are packed with chloroplasts and 78 00:07:06,610 --> 00:07:11,740 they leave this cuticle intact to protect themselves 79 00:07:11,740 --> 00:07:17,140 from birds trying to get at them. So they're kind of sealed away. They're using the leaf's 80 00:07:17,140 --> 00:07:22,210 natural protection to protect themselves while they mine away all 81 00:07:22,210 --> 00:07:27,220 the goodness inside the leaf. So the horse chestnut leaf miner is a bit of a baddie in a 82 00:07:27,220 --> 00:07:35,770 way, is probably the moth in Britain that causes people the most problems. 83 00:07:35,770 --> 00:07:42,130 Say, I got interested in moths when I was 12, and I just love the idea that. 84 00:07:42,130 --> 00:07:47,130 But there is actuality of putting out a bright light in the evening 85 00:07:47,130 --> 00:07:52,770 and then the next morning, you know, this truck filled with hundreds, 86 00:07:52,770 --> 00:07:58,110 sometimes of moths of all sorts of different species. It's quite accurate. 87 00:07:58,110 --> 00:08:03,450 Maybe I'm just lazy ducks. But, yeah, I've sort of from that 88 00:08:03,450 --> 00:08:08,890 moment, each trial, I've sort of got off track. My next birthday. 89 00:08:08,890 --> 00:08:14,160 Yeah. And doing it ever since. Yes. My page is looking 90 00:08:14,160 --> 00:08:19,740 at the impacts of light pollution on moths. It's a field 91 00:08:19,740 --> 00:08:24,930 sort of light pollution ecology has really exploded 92 00:08:24,930 --> 00:08:30,630 in the last 10 years or so. You've been steadily declining since 93 00:08:30,630 --> 00:08:35,760 since the late 60s. Been since we've been monitoring them. 94 00:08:35,760 --> 00:08:41,210 We suspect climate change is probably important. We suspect that land use changes are important. 95 00:08:41,210 --> 00:08:46,320 But people have often suggested that light pollution may also be playing a role. But that's just not 96 00:08:46,320 --> 00:08:51,320 really the evidence at the moment. So I sort of want to. Yeah, 97 00:08:51,320 --> 00:08:56,370 that that would be my not quite how I judge. I've done a good job on my page. But if 98 00:08:56,370 --> 00:09:07,500 I can just get a bit closer to answering my question, that would be that would be great. 99 00:09:07,500 --> 00:09:12,990 So this is my hunt for the whole night moth. And I'm just in the little park nearby 100 00:09:12,990 --> 00:09:18,030 and this is the kind of park where kids play football and and adults bring their children to 101 00:09:18,030 --> 00:09:23,850 play. It's a very ordinary place. But in the corner, there are three large poplar trees. 102 00:09:23,850 --> 00:09:29,010 And that's what drew my attention. And I had a look round the base of them and I could see holes, 103 00:09:29,010 --> 00:09:34,020 holes that looked like this. And if you see holes like that in a tree, those are exit holes. That's where 104 00:09:34,020 --> 00:09:39,120 some adult insect has emerged. And Hornet moths lay their eggs on 105 00:09:39,120 --> 00:09:44,430 poplar trees and the caterpillars go into the wood and they eat the wood. 106 00:09:44,430 --> 00:09:50,340 And so then not like the leaf miners taking the good stuff. That would be my way through the hard core stuff. 107 00:09:50,340 --> 00:09:55,380 And that's why they live for two or three years as larvae before they emerge as 108 00:09:55,380 --> 00:10:00,420 a moth. Now, of course, just finding the exit holes doesn't tell you that this colony is active. There's 109 00:10:00,420 --> 00:10:05,610 no way of knowing that. I just had a hint that there might be something going on. And I was lucky 110 00:10:05,610 --> 00:10:11,910 that it was the right time of year that I knew well, if they're here, they might be coming out around now. 111 00:10:11,910 --> 00:10:16,950 And so that's the first thing I did. I have to decide. Okay. I've seen the holes. I'm going to have 112 00:10:16,950 --> 00:10:22,000 a go at finding those moths. So it's the 21st of June. And I am back to look at my 113 00:10:22,000 --> 00:10:27,030 the holes in the bottom of the trees. I've been sick that day. And tonight for the first time, I have 114 00:10:27,030 --> 00:10:32,070 found a peaceful case. So what happens is the future is covered in spines 115 00:10:32,070 --> 00:10:37,410 and it manoeuvres its way to the exit hole, ready for the moth to emerge. I mean, it breaks 116 00:10:37,410 --> 00:10:42,990 clear of the exit hole and the moth itself emerges, leaving that people case behind. 117 00:10:42,990 --> 00:10:48,070 Outside the holes. I found one of those. That means their lawn is being set for six o'clock tomorrow morning. I 118 00:10:48,070 --> 00:10:53,220 am getting off, see if I can find one of these incredible moths. 119 00:10:53,220 --> 00:10:58,260 So I did indeed set my alarm. Six a.m. I rushed down here. I brought a book with me 120 00:10:58,260 --> 00:11:03,570 and my cataract sits on and felt like I was trying to read my book if I look too strange sitting standing 121 00:11:03,570 --> 00:11:09,420 around this tree. But as soon as I arrived and looked around the tree trunks. This is what I saw. 122 00:11:09,420 --> 00:11:15,240 And this is a newly emerged horn moth. And you can see the mimicry is astonishing. 123 00:11:15,240 --> 00:11:20,400 These big fiery moths that look exactly like a hornet or really are more like a queen 124 00:11:20,400 --> 00:11:25,800 wasp to me than a hornet. But you said you got a massive hit right there. Mimicry is excellent. 125 00:11:25,800 --> 00:11:30,830 And she hasn't pumped up her wings properly yet. They're still sure to not fully expanded. 126 00:11:30,830 --> 00:11:35,910 And I watched her do that for around half an hour. And I went back with a song in 127 00:11:35,910 --> 00:11:41,130 my heart. I've just been down to the popular trees and I was filming one of these amazing Hornet 128 00:11:41,130 --> 00:11:46,500 moths emerge. When I got home, look what was attached to my jumper. I have absolutely 129 00:11:46,500 --> 00:11:51,600 no idea how it got there because it was not the one I was filming, which was in a more advanced 130 00:11:51,600 --> 00:11:56,820 state. You can see that this one is just pumping its wings out now and stretching 131 00:11:56,820 --> 00:12:01,890 them out for their full length. So I have no idea how much a rack on the ground. 132 00:12:01,890 --> 00:12:07,050 I don't know whether it crawled out onto that and carried it home unwittingly. Obviously, 133 00:12:07,050 --> 00:12:12,540 I am going to take it back. Wow. 134 00:12:12,540 --> 00:12:17,670 So once I discovered that and I came back to the tree, I put my horn moth next to the one I'd 135 00:12:17,670 --> 00:12:23,430 watch demerging. The two females together. And then a male just descended out of nowhere 136 00:12:23,430 --> 00:12:29,940 and started to mate with one of the feedback holes, which was truly incredible. 137 00:12:29,940 --> 00:12:34,950 I came back even later again to find that my female, the first male, was still there with his 138 00:12:34,950 --> 00:12:40,140 female, but my female, he'd be taken home by accident. Now, also, how to partner with that one 139 00:12:40,140 --> 00:12:45,330 morning I actually saw full of these incredible Hornet moths. And I think it just goes 140 00:12:45,330 --> 00:12:50,910 to show that even just around the corner from you, in a very ordinary place, 141 00:12:50,910 --> 00:12:56,070 cars going past, people walking by bicycle and everything else, there are truly 142 00:12:56,070 --> 00:13:01,290 incredible things. I can honestly say that Hornet Moth, one of the most beautiful things I've ever 143 00:13:01,290 --> 00:13:06,330 seen and I know there was such a fleeting moment for me that makes it even better in a way. I 144 00:13:06,330 --> 00:13:11,400 probably won't see them for another year if ever again. You have to have that bit of luck. You've got to track down 145 00:13:11,400 --> 00:13:16,530 your colony and have the patience. But that's like all these amazing natural history moments. You always 146 00:13:16,530 --> 00:13:26,130 need that bit of luck, but put in the effort to and you might get this fantastic reward. 147 00:13:26,130 --> 00:13:32,040 Well, good evening. So it's like June. Just after midsummer. 148 00:13:32,040 --> 00:13:37,230 Beautiful, warm evening here. Blackbird singing away here and I'm here in my back 149 00:13:37,230 --> 00:13:42,540 garden in Oxford. So this is a 100 basis from County 150 00:13:42,540 --> 00:13:47,600 Road. So it's a terrorist house in East Oxford. And what 151 00:13:47,600 --> 00:13:52,920 I've done here is to set up a moth trap here in my back garden. So something I do 152 00:13:52,920 --> 00:13:58,470 most nights in the spring and summer. Particular if the weather's warm like like now says that the 153 00:13:58,470 --> 00:14:03,840 water be warm during the day. It's got me warm at night. And those are really good conditions for 154 00:14:03,840 --> 00:14:08,880 catching moths. So I set the trap that we're just going to have a look at it. So is the back 155 00:14:08,880 --> 00:14:14,280 garden. So it's a fairly standard suburban 156 00:14:14,280 --> 00:14:19,290 terrace garden. You know, quite a few trees here. We've got Big Bird 157 00:14:19,290 --> 00:14:24,420 Cherry Tree above me here. Crop up. There's lots of things, some fruit 158 00:14:24,420 --> 00:14:30,050 trees. So I think quicker than usual. And here on the garden table, so it's been pressed into service. 159 00:14:30,050 --> 00:14:35,220 So you to hold this moth trap. So this is what's called a Skinner trap. It's basically 160 00:14:35,220 --> 00:14:40,800 a plywood box. And mounted on top of it is a 161 00:14:40,800 --> 00:14:45,870 fluorescent tube light. So that produces a light. I'll turn it on when it 162 00:14:45,870 --> 00:14:51,540 gets dark and not light for reasons that are still a bit of a mystery attract 163 00:14:51,540 --> 00:14:56,580 in moths and other insects as well. I can see that basically it's got a couple 164 00:14:56,580 --> 00:15:01,650 of perspex sheets that acts as a sort of holding 165 00:15:01,650 --> 00:15:06,720 mechanism for most miles to get attracted and fall through this gap in the trap 166 00:15:06,720 --> 00:15:11,730 and inside the box. Here are lots of old egg boxes. Let's 167 00:15:11,730 --> 00:15:17,280 provide something for any moths that do get attracted to this trap to crawl into 168 00:15:17,280 --> 00:15:23,190 and shelter during the night. So we'll set this up going when it gets dark. 169 00:15:23,190 --> 00:15:28,540 And we might have a little bit of assistance from over here. Who's enjoying playing in the garden? 170 00:15:28,540 --> 00:15:33,630 OK. So just an update. It's about 11 o'clock. Put 171 00:15:33,630 --> 00:15:38,890 the trap on about an hour ago and it's running over there on the table. So you can see that that 172 00:15:38,890 --> 00:15:44,160 it's not a very bright light, but when it gets properly dark, it will become a bit more visible. 173 00:15:44,160 --> 00:15:50,850 So we'll leave that running all night and we'll cheque it first thing in the morning to see what we've caught. 174 00:15:50,850 --> 00:15:55,860 So it's quit by 6:00 the following morning and just 175 00:15:55,860 --> 00:16:00,880 turn the truck off. We can go along and look and see if we caught anything at all. 176 00:16:00,880 --> 00:16:06,150 OK, let's go. So could we get an idea 177 00:16:06,150 --> 00:16:11,190 if there's very much just from looking outside? You can see there 178 00:16:11,190 --> 00:16:16,560 might be some moths inside. You can see the red, black and white thing there. 179 00:16:16,560 --> 00:16:21,960 That's a scarlet tiger. And 180 00:16:21,960 --> 00:16:27,030 I can see a few of the moths inside, but we're ready. Good idea. When we open it up 181 00:16:27,030 --> 00:16:32,250 and go through the egg boxes one by one. So let's stop 182 00:16:32,250 --> 00:16:42,510 taking the first perspex sheet out here. 183 00:16:42,510 --> 00:16:49,650 See what we've got. 184 00:16:49,650 --> 00:16:55,560 So think on that first box that can see something 185 00:16:55,560 --> 00:17:00,890 sitting on this box here. So I got my thoughts. 186 00:17:00,890 --> 00:17:06,950 A moth called a coronet, so-called because of the shape of a patch of white 187 00:17:06,950 --> 00:17:19,180 on the wings. 188 00:17:19,180 --> 00:17:24,180 Small off there. So people divide moth's into into two groups. 189 00:17:24,180 --> 00:17:29,640 They're called the makram offs, the large moth's and the micro moths and Microsoft. 190 00:17:29,640 --> 00:17:34,790 So generally easier to identify someone. Micro moths come in and 191 00:17:34,790 --> 00:17:40,210 fight as well. That's part of it. I agree for about a dozen species. The Scapa rates, 192 00:17:40,210 --> 00:18:02,760 which are a little bit tricky, but I might have to have a closer look at that one later. 193 00:18:02,760 --> 00:18:07,890 So we've been through all the Trump about an hour later and I've gone through 194 00:18:07,890 --> 00:18:12,990 a few. Taking some photographs to try to identify some of the trickier ones. What I do once 195 00:18:12,990 --> 00:18:18,120 I've actually gone through the trap is to tap all of the boxes off into the bushes surrounding here, 196 00:18:18,120 --> 00:18:23,550 give them off somewhere to kind of hide during the day so they can recover and then fly off. 197 00:18:23,550 --> 00:18:28,600 As it gets dark following evening. So that was quite a good hold last night, actually. So 198 00:18:28,600 --> 00:18:33,750 a total of 27 different species that we call here in this this little average back 199 00:18:33,750 --> 00:18:38,770 garden in Oxford now. Yeah, that's a it's a pretty good number. So 200 00:18:38,770 --> 00:18:43,950 on a really good night, we might get here. Something up around, say, 50 species on 201 00:18:43,950 --> 00:18:49,060 some of the best nights I've ever had here. If you trap this sumba air in 202 00:18:49,060 --> 00:18:54,150 a more rural habitat, like, for example, a woodland cave, this marsh nearby, you 203 00:18:54,150 --> 00:18:59,460 might get even up as many as 150 species in a single night. One of the striking 204 00:18:59,460 --> 00:19:04,590 things about moths is that they're very, very seasonal in their appearance. So that species appear 205 00:19:04,590 --> 00:19:09,600 at particular times of year so that the species we get now are different than those we've got even two 206 00:19:09,600 --> 00:19:14,760 weeks ago. And those that we'll see in a couple of weeks time. So over the course of a year, you really 207 00:19:14,760 --> 00:19:20,190 get amazing diversity. So even in a back garden like this. So I've been 208 00:19:20,190 --> 00:19:25,380 looking at the moths here and not not going over the top with it. Yeah, I'm fairly 209 00:19:25,380 --> 00:19:30,570 interested in them, but I've probably seen getting on for about 450 210 00:19:30,570 --> 00:19:36,000 species in the back garden here. There's about two and a half thousand species in Britain, though, so 211 00:19:36,000 --> 00:19:55,720 I've got a long way to go still before I've really kind of completed the set.