What's the worst bug on the planet? You might vote for the horsefly or perhaps the wasp, but for many people, the worst offender is by far the mosquito. The buzzing, the biting, the itching, the mosquito is one of the most commonly detested pests in the world. In Alaska, swarms of mosquitos can get so thick that they actually asphyxiate caribou. And mosquito-borne diseases kill millions of people every year. The scourge that is the mosquito isn't new. Mosquitoes have been around for over a hundred million years and over that time have coevolved with all sorts of species, including our own. There are actually thousands of species of mosquitos in the world, but they all share one insidious quality: they suck blood, and they're really, really good at sucking blood. Here's how they do it. After landing, a mosquito will slather some saliva onto the victim's skin, which works like an antiseptic, numbing the spot so we don't notice their attack. This is what causes the itchy, red bumps, by the way. Then the bug will use its serrated mandibles to carve a little hole in your skin, allowing it to probe around with its proboscis, searching for a blood vessel. When it hits one, the lucky parasite can suck two to three times its weight in blood. Turns out we don't really like that too much. In fact, humans hate mosquitos so much that we spend billions of dollars worldwide to keep them away from us -- from citronella candles to bug sprays to heavy-duty agricultural pesticides. But it's not just that mosquitos are annoying, they're also deadly. Mosquitos can transmit everything from malaria to yellow fever to West Nile virus to dengue. Over a million people worldwide die every year from mosquito-borne diseases, and that's just people. Horses, dogs, cats, they can all get diseases from mosquitoes too. So, if these bugs are so dastardly, why don't we just get rid of them? We are humans after all, and we're pretty good at getting rid of species. Well, it's not quite so simple. Getting rid of the mosquito removes a food source for lots of organisms, like frogs and fish and birds. Without them, plants would lose a pollinator. But some scientists say that mosquitos aren't actually all that important. If we got rid of them, they argue, another species would simply take their place and we'd probably have far fewer deaths from malaria. The problem is that nobody knows what would happen if we killed off all the mosquitos. Something better might take their spot or perhaps something even worse. The question is, are we willing to take that risk? (Buzzing)
Kateri je najhujši mrčes na planetu? Morda glasujete za obada, morda za oso, a za veliko ljudi je daleč najhujši zločinec komar. Brenčanje, pikanje, srbenje, komar je eden izmed najbolj pogosto zaničevanih nadlog na svetu. Na Aljaski so roji komarjev lahko tako gosti, da lahko dejansko zadušijo karibuja. Bolezni, ki jih prenašajo, ubijejo milijone ljudi vsako leto. Sovraštvo do komarja ni nič novega. Komarji so tu več kot 100 milijonov let in sočasno so se razvijali z različnimi vrstami, tudi z našo. Obstaja na tisoče vrst komarjev na svetu, a vsi si delijo eno zahrbtno lastnost: sesajo kri in res, res dobri so v tem. Takole to storijo. Po pristanku komar izpljune nekaj sline na kožo žrtve, ki deluje kot antiseptik, omrtviči točko, tako da napada ne opazimo. Mimogrede, to je tisto kar povzroči srbeče, rdeče pike. Nato uporabi svoje nazobčane čeljusti, da izrežejo majhno luknjo v vašo kožo, da lahko dreza vanjo s svojim rilčkom in išče žilo. Ko jo najde, ta srečni parazit lahko izsesa dvakratno ali trikratno lastno težo v krvi. Izkaže se, da nam to ni preveč všeč. Ljudje jih tako zelo sovražimo, da smo zapravili na milijarde dolarjev po celem svetu, da bi jih odgnali - od citronela sveč, sprejev proti mrčesu, do močnih agrikulturnih pesticidov. Ne samo, da so komarji nadležni, so tudi smrtonosni. Komarji lahko prenašajo karkoli od malarije do rumene mrzlice do virusa zahodnega Nila in do vročice denga. Več kot milijon ljudi na svetu umre vsako leto od bolezni, ki jih prenašajo komarji, in to samo ljudje. Konji, psi, mačke, vsi lahko dobijo bolezni od komarjev. Torej, če so ti žužki tako nemarni, zakaj se jih enostavno ne znebimo? Saj smo vendarle ljudje in precej dobri smo pri iztrebljanju vrst. No, ni tako preprosto. Če se znebimo komarja, izgubimo vir hrane za veliko organizmov kot naprimer žabe, ribe in ptiče. Brez njih bi rastline izgubile opraševalca. Nekateri znanstveniki pravijo, da komarji sploh niso tako pomembni. Če se jih znebimo, pravijo, bi neka druga vrsta prevzela njihovo mesto in najbrž bi imeli mnogo manj smrti zaradi malarije. Problem je, da ne vemo, kaj bi se zgodilo, če bi pobili vse komarje. Morda bi jih nadomestilo nekaj boljšega, ali pa morda še nekaj hujšega. Vprašanje je, ali smo to tveganje pripravljeni sprejeti?