Necrophila

Transcription

We're here today because the town of Hanover and Jo Daviess Conservation Foundation have acquired this old soybean field and they're restoring it as a prairie. And they've been working here for about six years and we're surveying the insect population. Okay. So this is a carrion trap. - Ewwww!! Wow. - Oooh, lots of good stuff! So, there is lots of stuff in here. So how long was this in the ground for? Four and a half weeks, about a month. - Really. And that's a tea strainer, That's a tea strainer. - that you're gonna strain through. That's very sophisticated. Yeah, we are. So, it's a carrion trap, so what does that mean? Okay, so this, - Yeah. had four ounces of chicken liver in it- Sounds appetizing. -hung over the bucket. And the carrion trap- they're compelled by the rotting meat smell to fall in. And there's... Those are millipedes, yeah. - What is it- those look like a lot of millipedes. Tons of millipedes. - There's a bunch of millipedes in here, bunch of grasshoppers. Oh, those are some huge grasshoppers. Yeah, this is one of the carrion beetles, Necrophila americana. - Ohhh. Those are kinda cool looking. That's one of the carrion beetles that we find here, and it's really hard to tell what you've got until you get back to the museum and put it under the scope. Yeah, and identify a lot of the smaller ones. - Yeah, and then you identify the smaller stuff. Lots of isopods- roly-polies. Yeah. - Yeah, lots of different kinds of millipedes. How many different species of millipedes do you think are out here? Out here in this prairie? - Yeah. Between fifteen and twenty. Really? - Mmhmm. I didn't know there were that many. There are at least six different orders of millipedes out here: Polydesmids, Spirobolids, Spirostreptids, Julids, Platydesmids, Polyxenidas, and possibly Polyzoniidas. So what does that mean? Do they have like, different numbers of legs or different numbers of body segments, or- They have different numbers of legs, different numbers of body segments, uh, their reproductive organs are in different places on the body. Oh, they're not just like, where you would assume like, the genitals to be? No, some of them, the male genitals are on the second segment, some of them are on the seventh, some of them are on the eighth. So the second segment, like, on the neck. - Just right behind the neck. So you have gonads like, on your head. - Yeah, mhmm. That's pretty crazy. - They call them gonopods in millipedes. So they're right behind, and they're on the underside, on the belly. - Okay, yeah. Right behind the head, or a few segments further down, or a few segments further down. - Okay. And the females all have different types of genitalia as well. Well, you gotta correspond to the having gonads on your neck. - Yeah. And then you just put the bucket back in the ground, and this is just propylene glycol. So you don't want to use alcohol out here because it'll evaporate. - It'll evaporate away. And so you use that... - So you use propylene glycol, which is not toxic to mammals. So if a raccoon gets in, and drinks the fluid, it won't hurt him. This is 50% propylene glycol, 50% water, and a couple of ounces of liquid dishsoap. And the dish soap breaks the surface tension. - Okay. So when the insects fall in, they sink. - Yeah, instead of... They don't just float, because if they floated, in a couple hours the surface would be covered with insects. Other ones would land and just fly away. - Ohh, I see. So they fall in, they sink, and they just keep falling in and sinking. Now here's the part that's so much fun for you. This is chicken liver, wrapped in gauze, tied up. - That's- Ooh. How long has this chicken liver been sitting out? About two and a half days at room temperature. So it's starting to smell pretty good. Oh, mmm. It's nice and fragrant, yeah. - Isn't that appetizing? So then you just hang that over the bucket, and the smell of the rotting chicken liver attracts all those carrion eating beetles. They fall in the bucket and sink down to the bottom. So why are you specifically trying to get carrion beetles? A lot of other things will fall in as well. Some of the beetles that are attracted to carrion are considered habitat indicators. One of the carrion beetles called Nicrophorus marginatus- that's only found in fairly high quality prairies. The last set of traps we set had Nicropherus marginatus in it. They also had a scarab called Phanaeus vindex, which is a dung roller that is also only found in high quality prairies. So six years ago there were soybeans here, and now you've got a nice, healthy prairie. - Yeah. So when you get a healthy prairie and you have all these good bugs as good indicators of how healthy the prairie is, that's going to obviously attract birds and mammals, and all kinds of things to come back to this area - If you get... that maybe hadn't been here for years. - If you've got good insects, you get more reptiles and amphibians, you get more birds. If you get more birds, more reptiles and amphibians, you get more mammals. And the populations and the community just keeps building and building over the years. This is exciting! So now we've got three or four pitfall traps, - Okay. which are the same thing, but without the bait. Occasionally a mouse or something will fall in and it can't get out, but then we take it to the mammal division at the museum. - Oh, yeah. And it goes into their collections, and then they have records of them being here. - Yeah. So nothing ever goes to waste. - Yeah. And there's some beetles, too. See the carabid beetles? - Wow. Some grasshoppers, yeah. That's a ground beetle, a carabid beetle. - There's some spiders in there. Yeah, there's spiders, and you don't usually find very many spiders in carrion traps, because most spiders are actually repulsed by the smell of carrion. - Really? So spiders walk up close to a carrion trap, and then veer away. Oh, that's interesting. I would have thought that everything would just, you know, swarm to the stink smell. There are a lot of beetles that are repulsed by the smell of carrion also. - Right. Oh, okay. So they fall into these kinds of traps. So you gotta make sure you have diverse, different ways of collecting everything. The more ways you have of collecting, the more different types of insects you're going to find. So far we've collected 800 spiders and insects at this point, - Wow. in just over the same period of four weeks. 800 different species in four weeks. - In four weeks, yes. We could easily find 1200-1500 over a full summer. So we should get a whole lot more than we have so far. - That's exciting. I can see where you'd really get into this. This seems relatively low technology. It is really very low cost, low technology, and basically, anybody can do it. You can go to the car part store and get a little bit of propylene glycol, put the holes in the ground, - You just need some dish soap. some dish soap, some water, - some old railroad spikes. and, to do the carrion trap, a little bit of chicken liver. You could set a full set of traps for fifteen bucks. - That's awesome. And then some alcohol, some rubbing alcohol to put them in. - Yeah. Come on, start. We're gonna go back, right in there between those trees and string the line. It is beautiful back here. Isn't this a cool place? Yeah. This is gorgeous. Have you set up a sheet back here before? Yeah, I have, and if the weather's good, it does pretty well. - And... If the weather's too cold, it doesn't do anything. Okay. Bring it back around again. You have to have one to hang the sheet from and one to hang the light from. Oh, that makes sense. How long have you been doing this? How, like, how long have you been going out into the field and collecting bugs? 17-18 years now. I'd collect live things and bring them home and watch them. - And watch them? I'd watch caterpillars eat, and grow, and spin their cocoons, and - Yeah. wait for them to emerge whenever they came out. You know, there's an old saying- If you love what you do, you'll never work another day in your life. - Yeah. I get a paycheck every other week, but I haven't worked in 18 years. For me it's great fun, and I get paid for it. I get paid for my hobby, what could be better? This will hold it down and keep the sheet from blowing. Ohp, there was a spider. This is a mercury halide light. It's a 250 watt bulb. And that gets hung up here.