Pesticides Are Making Bees Dumber殺蟲劑讓蜜蜂變笨了

凱特·埃施納

Even if they survive， they might not thrive.雖可存活，恐難繁衍。

You might associate honeybees and bumblebees with their cute， fuzzy shape and seemingly aimless interest in flowers. But beneath the yellow-and-black （mostly） stripes lies an incredible mind. A new study pooled evidence from 23 studies of honeybees and bumblebees： its conclusions， which build on years of bee research， point to the fact that levels of pesticides currently considered safe to use may still have a big effect on bee colony survival.

Although they might look simple， “bees have a very difficult job，” says study author Harry Siviter， a graduate student at Royal Holloway University of London. To efficiently find and collect food to bring back to the hive， worker bees have to quickly learn to recognize （and then memorize） the most effective foraging routes， he says. To top it off， the routes change with the seasons and with other factors. Honey bees even remember which flowers theyve visited recently， so they dont waste time going there again.

All of this takes a good memory and an ability to learn—things that many lab studies have observed in honey bees using the “proboscis extension assay.” When a bee comes near the scent of sugary， delicious nectar， it starts to stick its tongue out. In experiments， researchers exposed bees to pesticides and then watched what they did when prompted to forage， looking to see when—and whether—they stuck their tongues out. Siviter and his colleagues took the data of 23 of these studies and performed a large-scale analysis of the results.

They found that doses of pesticides that are the equivalent of what a bee might encounter in a field “had significant negative effects on learning and memory.” That was true both when bees were suddenly exposed to a lot of pesticide， and when they got a little bit over a long time. It was also true regardless of whether the bees were exposed to neonicotinoids， a class of pesticides that has been around since the 1990s and is being increasingly regulated today， or other pesticides.

Current pesticide regulations are geared toward making sure they arent used at levels that kill bees. But these currently legal amounts apparently make the worker bees dumber， which could have effects for species survival. “Regulation and policy should move toward addressing the sub-lethal effects of pesticides，” Siviter says.

The other question these findings implicitly raise is how these pesticides affect less-studied types of bee. Bees dont all live collectively， University of Guelph scientist Elizabeth Bates told Popular Science in an interview. “Many wild bees do not live in colonies，” she says， “and if their learning or memory are affected， there are no other bees to help out or pick up the slack.”

Ohio State University entomologist Reed Johnson told Popular Science in an email interview， the question is： “Can pesticides ever be used safely around bees？” This study， which in one sense has the strength of 23 studies worth of evidence， “suggests that the answer is ‘no，” he wrote.

The follow-up question goes deep into one of our most fundamental needs—food. Pesticides are an essential part of large-scale industrial agriculture， and some amount of honeybee exposure is inevitable. The question， then—which hasnt been answered by regulation to date， Johnson says—is how much harm to bees is acceptable.

As ever， more research is needed. But this study is worth paying attention to， University of Ottawa bee conservationist Jeremy Kerr told Popular Science. Its conclusions are based on evidence from over 100 individual experiments included in the 23 studies， he says， lending their findings weight. “The lesson that emerges is that honeybees begin to lose their ability to learn and to remember when they are exposed to neonicotinoids，” he writes.

The power of this paper is that it shows “a consensus of knowledge” on this question， he wrote. That result is something pesticide policy-makers could pay attention to. “With restrictions on neonicotinoids increasing globally， many will be looking to alternative chemicals for crop protection，” Bates says. Its important to think about what those chemicals might be doing to the bees.

說(shuō)起蜜蜂與大黃蜂，你可能會(huì)聯(lián)想到它們可愛而毛茸茸的身體及其對(duì)花朵看似漫無(wú)目的的喜愛。然而，它們黃黑相間（大多如此）的條紋之下卻有著令人難以置信的頭腦。一項(xiàng)新研究收集了23項(xiàng)有關(guān)蜜蜂和大黃蜂研究的證據(jù)：結(jié)論基于多年的蜜蜂研究，指出目前認(rèn)為安全的殺蟲劑濃度對(duì)蜂群的生存仍可能產(chǎn)生巨大影響。

研究報(bào)告的作者、倫敦大學(xué)皇家霍洛威學(xué)院研究生哈里·西維特表示，盡管蜜蜂看上去簡(jiǎn)單，但“它們的工作很艱難”。他說(shuō)，為了有效地找到和收集食物帶回蜂巢，工蜂必須迅速學(xué)會(huì)識(shí)別（然后記?。┳钣行У囊捠陈肪€。最為重要的是，路線會(huì)隨著季節(jié)和其他因素的變化而變化。蜜蜂甚至記得最近采過(guò)哪些花，因此不會(huì)浪費(fèi)時(shí)間再去一次。

這一切都需要良好的記憶力和學(xué)習(xí)能力——許多實(shí)驗(yàn)室研究都通過(guò)“喙伸試驗(yàn)”觀察到了這些特質(zhì)。蜜蜂靠近香甜美味的花蜜時(shí)，就開始伸出舌頭。研究人員在實(shí)驗(yàn)中將蜜蜂暴露于殺蟲劑之中，然后觀察它們?cè)诒淮偈挂捠硶r(shí)的行為，看看它們什么時(shí)候或者是否還會(huì)伸出舌頭。西維特及其同事收集了其中23項(xiàng)研究數(shù)據(jù)，并對(duì)研究結(jié)果進(jìn)行了大規(guī)模分析。

他們發(fā)現(xiàn)，蜜蜂在田間可能接觸到的相當(dāng)劑量的殺蟲劑“對(duì)其學(xué)習(xí)和記憶產(chǎn)生了顯著的負(fù)面影響”。無(wú)論蜜蜂是突然接觸大量殺蟲劑還是長(zhǎng)期少量接觸，情況都是如此。不管蜜蜂是暴露于新煙堿類殺蟲劑——一種自1990年代開始使用、如今監(jiān)管日益嚴(yán)格的農(nóng)藥——還是其他殺蟲劑之中，情況亦是如此。

現(xiàn)行的殺蟲劑管理?xiàng)l例旨在確保其使用濃度不至殺死蜜蜂，但這些目前合法的劑量顯然使工蜂變笨了，進(jìn)而可能影響物種生存。西維特認(rèn)為：“監(jiān)管和政策應(yīng)當(dāng)轉(zhuǎn)向解決殺蟲劑的亞致死效應(yīng)問(wèn)題?！?/p>

這些發(fā)現(xiàn)間接提出了另一問(wèn)題，即那些殺蟲劑如何影響研究尚淺的蜂類。圭爾夫大學(xué)科學(xué)家伊麗莎白·貝茨接受《科技新時(shí)代》采訪時(shí)稱，蜜蜂并不都是群居的。她表示：“許多野生蜜蜂并非群居，如果它們的學(xué)習(xí)或記憶受到影響，不會(huì)有其他同類伸出援手或收拾殘局?！?/p>

俄亥俄州立大學(xué)昆蟲學(xué)家里德·約翰遜在《科技新時(shí)代》電子郵件采訪中表示，問(wèn)題在于：“在蜜蜂出沒(méi)地使用殺蟲劑能否保證它們的安全？”他寫道，某種意義上，這項(xiàng)研究具有23項(xiàng)研究的證據(jù)優(yōu)勢(shì)，其“給出的答案是‘否”。

后續(xù)問(wèn)題深入到我們最基本的需求之一——食物。殺蟲劑在大規(guī)模工業(yè)化農(nóng)業(yè)中必不可少，蜜蜂一定程度暴露其中無(wú)法避免。那么，問(wèn)題就在于蜜蜂能接受多大程度的傷害——約翰遜表示，監(jiān)管迄今尚未解答這一問(wèn)題。

與以往一樣，還需進(jìn)行更多的研究。但渥太華大學(xué)蜜蜂保護(hù)學(xué)家杰里米·克爾告訴《科技新時(shí)代》，這項(xiàng)研究值得關(guān)注。他說(shuō)，該研究的結(jié)論基于23項(xiàng)研究中100多個(gè)獨(dú)立實(shí)驗(yàn)的證據(jù)，這讓他們的發(fā)現(xiàn)更有分量。他寫道：“研究給出的啟示是，蜜蜂接觸新煙堿類殺蟲劑后，會(huì)開始喪失學(xué)習(xí)和記憶的能力。”

他寫道，這份報(bào)告的價(jià)值在于表現(xiàn)出對(duì)這一問(wèn)題“在知識(shí)層面達(dá)成的共識(shí)”。這一結(jié)果值得殺蟲劑政策制定者關(guān)注。貝茨說(shuō)：“隨著全球?qū)π聼焿A類殺蟲劑的限制不斷增加，許多人將尋求替代化學(xué)品來(lái)保護(hù)農(nóng)作物。”考慮這些化學(xué)物質(zhì)可能對(duì)蜜蜂產(chǎn)生何種影響頗為重要。? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?□

（譯者為“《英語(yǔ)世界》杯”翻譯大賽獲獎(jiǎng)選手;譯者單位：山東省文登整骨醫(yī)院）