吳雯

在良渚自然學(xué)堂里，我們每次安排孩子到農(nóng)園進(jìn)行實(shí)際觀察前，會(huì)組織他們討論：你們覺得什么蟲是害蟲？孩子們非常天真地以昆蟲對(duì)自己的好壞來(lái)判斷，如他們認(rèn)為菜青蟲是害蟲，因?yàn)樗圆巳~。

我問(wèn)他們，菜青蟲變成美麗的蝴蝶之后，就會(huì)幫植物傳粉造福人類，它是害蟲還是益蟲呢？孩子們似乎有點(diǎn)明白了，即便都是從人類的角度來(lái)看，有害或有益也不是一成不變的。

有了這樣一個(gè)思辨的基礎(chǔ)，我們進(jìn)一步帶孩子考察發(fā)現(xiàn)不同的昆蟲有哪些益處和害處。

蒼蠅讓人惡心，會(huì)傳播各種疾病。但我用相機(jī)拍過(guò)上百種不同的蒼蠅和它的“親戚們”，這種廣泛存在于自然界的雙翅目昆蟲，其實(shí)也是傳粉的主力軍。據(jù)統(tǒng)計(jì)，70%需要?jiǎng)游飩鞣鄣闹参锷希加谢档纳碛?，而麗蠅是芒果不可替代的授粉昆蟲。孩子們?cè)趯?duì)傳粉昆蟲調(diào)查時(shí)發(fā)現(xiàn)，除了蜜蜂、蝴蝶之外，傳粉的昆蟲多種多樣，包括肉眼都看不清的薊馬，無(wú)處不在的螞蟻，各種蜂、蛾子，也包括各種蒼蠅。

毛毛蟲常被歸類為害蟲，它們是鱗翅目蝴蝶或者蛾子的幼蟲。它們雖然會(huì)吃掉農(nóng)園植物一部分的葉子，但實(shí)際上它在整個(gè)生態(tài)鏈中它承擔(dān)著食物提供者的角色。毛毛蟲的蛋白質(zhì)含量很高，是各種鳥類、蛙類的食物來(lái)源。尤其是大部分鳥類在繁衍后代的時(shí)候，都會(huì)以昆蟲為主食。就算不使用農(nóng)藥，一般也不會(huì)出現(xiàn)某種農(nóng)業(yè)蟲害大面積爆發(fā)的情況。當(dāng)孩子觀察到菜青蟲從卵到幼蟲到蛹再到成蟲的不同階段，尤其是發(fā)現(xiàn)原來(lái)菜青蟲是菜粉蝶的幼蟲之后，他們?cè)倏匆娒x就不會(huì)一腳踩死，而是希望知道它們長(zhǎng)大羽化之后，會(huì)成為哪種蝴蝶或者蛾子。

蚜蟲一路伴隨著植物的演化，發(fā)展成龐大的家族，已知種類有四千多種，寄生的植物包含了全部被子植物和松柏綱的所有科。蚜蟲是演化得非常成功的一類昆蟲：它們成群結(jié)隊(duì)，用腹管吸食植物的汁液；它們繁殖最快，不但一年可以有30個(gè)世代，而且還具備孤雌繁殖等絕技；如果食物不夠，它們還能長(zhǎng)出翅膀，遷飛到其他植株。孩子們考察發(fā)現(xiàn)：蚜蟲也是其他昆蟲重要的食物供應(yīng)者，會(huì)被食蚜蠅、瓢蟲、寄生蜂、蟹蛛、草蛉等捕食；大部分蚜蟲是單食性，而蚜蟲的天敵們可以吃各種蚜蟲，這樣就不會(huì)出現(xiàn)蚜蟲大面積爆發(fā)的情況。這些深入的觀察可以讓孩子們思考現(xiàn)代農(nóng)業(yè)方面的問(wèn)題，也許以后他們就能找到更合理的方式來(lái)應(yīng)對(duì)所謂的農(nóng)業(yè)害蟲。

孩子們?cè)谵r(nóng)園發(fā)現(xiàn)，蚜蟲有個(gè)“好朋友”——螞蟻，它經(jīng)常在植物上爬來(lái)爬去，原來(lái)它是在放牧蚜蟲，為了吃蚜蟲排出的蜜露。螞蟻為此會(huì)在蚜蟲的周圍保護(hù)它們，與前來(lái)吃蚜蟲的瓢蟲“打架”。孩子們?cè)诜氐臅r(shí)候挖出螞蟻窩，發(fā)現(xiàn)它們是重要的分解者，會(huì)把小的果實(shí)、昆蟲的尸體搬運(yùn)到巢穴里面享用。孩子們還發(fā)現(xiàn)，螞蟻還是了不起的土壤“工程師”，它們?cè)诘叵碌某惭ň邆涠鄠€(gè)分區(qū)。

蠐螬也是常在地下被挖到的一種蟲子，它主要吃植物的根，化蛹變成金龜子一類的成蟲又會(huì)吃植物的葉子，這也是農(nóng)業(yè)害蟲。我每次挖到蠐螬都很開心，因?yàn)轱曫B(yǎng)后可以養(yǎng)出漂亮的甲蟲。甲蟲是生態(tài)系統(tǒng)里面的分解者，也給鳥類提供食物，它多樣絢麗的外表，還提供了審美的價(jià)值。

人們把昆蟲分為害蟲和益蟲，是從農(nóng)業(yè)的需求來(lái)劃分的。人類以為靠著殺蟲劑、除草劑就能摒棄農(nóng)作物的一切不利因素，卻引發(fā)了更多的環(huán)境問(wèn)題。其實(shí)昆蟲在生態(tài)中擁有非常重要的功能，它們?yōu)橹参飩鞣?，它們給其他生物提供食物，有的是重要的分解者，有的是土壤“工程師”，有的是維護(hù)生態(tài)平衡的天敵昆蟲，還有的甚至是我們審美的對(duì)象、靈感的源泉。

良渚農(nóng)園很少使用農(nóng)藥化肥，用堆肥來(lái)改良土壤，用多樣的植物為昆蟲提供食物和棲息地，與昆蟲分享植物。這樣一個(gè)招蜂引蝶的農(nóng)園，是自然教育、生態(tài)教育的良好場(chǎng)所，它能夠激勵(lì)孩子們走進(jìn)自然，能夠啟發(fā)我們反思人與自然的關(guān)系，為我們提供一種超越人類中心主義的生態(tài)觀。

Nature Education Should Reflect on the Relationship between Man and Nature

WU Wen

中圖分類號(hào)：G424文獻(xiàn)標(biāo)識(shí)碼：ADOI：10.16400/j.cnki.kjdk.2021.30.002

WU Wen

Founder of "Secret Land Guardian" of Environmental Protection and Nature Education Communication Organization

Founder of Liangzhu Nature School

Distinguished Expert of Natural Education in "Science and Education Guide"

In Liangzhu nature school， we organize our chil？ dren to discuss： what insects do you think are pests before we arrange them to go to the farm for actual observation？ Children are very naive to judge them？ selves by insects. For example， they think that Pieris rapae is a pest because it eats vegetable leaves.

I asked them， after the cabbage worm becomes a beautiful butterfly， it will help plants pollinate for the benefit of mankind. Is it a pest or a beneficial insect？ Children seem to understand that even from a human point of view， harmful or beneficial is not invariable.

With such a speculative basis， we will further take our children to investigate and discover the ben？ efits and harms of different insects.

Flies are disgusting and can spread all kinds of diseases. But I have photographed hundreds of differ？ ent flies and their "relatives" with my camera. This kind of Diptera Insect， which widely exists in nature， is actually the main force of pollination. According to statistics， 70% of plants that need animal pollina？ tion have the figure of gadfly， and lifly is an irre？ placeable pollination insect of mango. During the in？ vestigation of pollinating insects， children found that there are a variety of pollinating insects except bees and butterflies， including thrips that cannot be seen by the naked eye， ubiquitous ants， all kinds of bees， moths and all kinds of flies.

Caterpillars are often classified as pests. They are the larvae of Lepidoptera butterflies or moths. Al？ though they eat some leaves of farm plants， they actu？ ally play the role of food provider in the whole eco？ logical chain. Caterpillars have high protein content and are the food source of various birds and frogs. In particular， most birds will take insects as their sta？ ple food when they reproduce. Even if pesticides are not used， there will generally be no large-scale out？ break of certain agricultural pests. When children ob？ serve the different stages of Pieris rapae from egg to larva to pupa and then to adult， especially after they find that Pieris rapae is the larva of Pieris rapae， they will not step on the caterpillars again， but want to know what kind of butterfly or moth they will be？ come after they grow up and eclosion.

Along with the evolution of plants， aphids have developed into a huge family. There are more than 4000 known species. Parasitic plants include all an？ giosperms and all families of conifers. Aphids are a class of insects that have evolved very successfully： they flock and suck plant juice with their ventral tubes； They reproduce the fastest. They can not only have 30 generations a year， but also have unique skills such as parthenogenetic reproduction； If there is not enough food， they can grow wings and migrate tootherplants.Thechildren’sinvestigationfound that aphids are also important food suppliers for oth？ er insects， and will be preyed on by aphid flies， la？ dybugs， parasitic wasps， crab spiders and sandflies； Most aphids are monophagous， and their natural ene？ mies can eat all kinds of aphids， so there will be no large-scale outbreak of aphids. These in-depth obser？ vations can make children think about modern agri？ culture， and maybe they can find a more reasonable way to deal with the so-called agricultural pests in the future.

The children found that the aphid has a "good friend" - ant. It often crawls around on plants. It turns out that it is grazing aphids in order to eat the honeydew discharged by aphids. For this reason， ants will protect them around aphids and "fight" with lady？ bugs who come to eat aphids. Children dig out ant nests when turning over the ground and find that theyareimportantdecomposers.Theywillcarry small fruits and insect bodies to the nest for enjoy？ ment.Thechildrenalsofoundthatantsarealso great soil "engineers"， and their underground nests have multiple zones.

Grub is also a kind of insect often dug under？ ground. It mainly eats plant roots， pupates into bee？ tles， and adults will eat plant leaves， which is also anagriculturalpest.Everytimetheauthordigs grubs， she is very happy， because after feeding， the author can raise beautiful beetles. Beetles are decom？ posers in the ecosystem and provide food for birds. Their diverse and gorgeous appearance also provides aesthetic value.

Insects are divided into pests and beneficial in？ sects according to the needs of agriculture. Humans think that relying on pesticides and herbicides can abandonalladversefactorsofcrops，butithas caused more environmental problems. In fact， insects have very important functions in ecology. They polli？ nateplantsandprovidefoodforotherorganisms. Some are important decomposers， some are soil "engi？ neers"， some are natural enemies to maintain ecologi？ cal balance， and some are even the object of our aes？ thetics and the source of inspiration.

Liangzhu agricultural park rarely uses pesticides and chemical fertilizers， uses compost to improve the soil， uses a variety of plants to provide food and hab？ itat for insects， and shares plants with insects. Such an agricultural garden that attracts bees and butter？ flies is a good place for natural education and ecolog？ ical education. It can inspire children to enter na？ ture， inspire us to reflect on the relationship between man and nature， and provide us with an ecological view beyond anthropocentrism.