Pod star\u00fdm dubem le\u017e\u00ed stovky \u017ealud\u016f. N\u011bkter\u00e9 jsou leskl\u00e9, tvrd\u00e9 a\u00a0vypadaj\u00ed dokonale. Jin\u00e9 v\u00a0sob\u011b maj\u00ed drobnou kulatou d\u00edrku, sotva v\u011bt\u0161\u00ed ne\u017e \u0161pi\u010dka tu\u017eky. V\u011bt\u0161ina lid\u00ed ji p\u0159ejde bez pov\u0161imnut\u00ed. Mo\u017en\u00e1 si pomysl\u00ed, \u017ee \u017ealud po\u0161kodil hmyz. Mo\u017en\u00e1 ho odkopnou z\u00a0cesty nebo nechaj\u00ed le\u017eet mezi list\u00edm. Jen m\u00e1lokdo tu\u0161\u00ed, \u017ee pr\u00e1v\u011b takov\u00fd nen\u00e1padn\u00fd otvor je stopou jednoho z\u00a0nejpozoruhodn\u011bj\u0161\u00edch p\u0159\u00edb\u011bh\u016f, kter\u00e9 se v\u00a0na\u0161ich les\u00edch odehr\u00e1vaj\u00ed.<\/p>\n
Nosatec \u017ealudov\u00fd (Curculio glandium)<\/p>\n
Hlavn\u00edm hrdinou je nosatec \u017ealudov\u00fd. Drobn\u00fd brouk, kter\u00fd na prvn\u00ed pohled p\u016fsob\u00ed t\u00e9m\u011b\u0159 komicky, ale z\u00e1rove\u0148 roztomile. M\u00e1 kulat\u00e9 t\u011blo, dlouh\u00e9 nohy a\u00a0p\u0159edev\u0161\u00edm n\u00e1padn\u00fd rypec, kter\u00fd p\u0159ipom\u00edn\u00e1 miniaturn\u00ed chobot. Kdyby byl velk\u00fd jako pes nebo srnec, stal by se pravd\u011bpodobn\u011b jedn\u00edm z\u00a0nejslavn\u011bj\u0161\u00edch zv\u00ed\u0159at evropsk\u00fdch les\u016f. Jen\u017ee m\u011b\u0159\u00ed sotva n\u011bkolik milimetr\u016f, a\u00a0tak v\u011bt\u0161ina lid\u00ed o\u00a0jeho existenci v\u016fbec nev\u00ed. P\u0159esto jde o\u00a0tvora, jeho\u017e \u017eivotn\u00ed cyklus pat\u0159\u00ed mezi nejzaj\u00edmav\u011bj\u0161\u00ed v\u00a0cel\u00e9 \u0159\u00ed\u0161i hmyzu.<\/p>\n
Kdy\u017e \u010dlov\u011bk poprv\u00e9 spat\u0159\u00ed samici nosatce \u017ealudov\u00e9ho zbl\u00edzka, okam\u017eit\u011b ho zaujme jej\u00ed rypec. U\u00a0samic b\u00fdv\u00e1 dokonce del\u0161\u00ed ne\u017e cel\u00e9 t\u011blo. Nen\u00ed to ozdoba ani jako n\u00e1stroj ur\u010den\u00fd k\u00a0obran\u011b. Ve skute\u010dnosti je to dokonale specializovan\u00fd n\u00e1stroj, bez kter\u00e9ho by tento druh nemohl existovat. V\u00a0l\u00e9t\u011b, kdy\u017e na dubech dozr\u00e1vaj\u00ed mlad\u00e9 \u017ealudy, za\u010d\u00edn\u00e1 obdob\u00ed, na kter\u00e9 \u010dekala cel\u00fd rok. Samice se pohybuje po v\u011btv\u00edch a\u00a0pe\u010dliv\u011b vyb\u00edr\u00e1 vhodn\u00fd \u017ealud. Ne p\u0159\u00edli\u0161 mal\u00fd, ne po\u0161kozen\u00fd nebo napaden\u00fd jin\u00fdm hmyzem. Pot\u0159ebuje takov\u00fd, kter\u00fd nab\u00eddne dostatek potravy pro jej\u00ed budouc\u00ed potomstvo. Jakmile ho najde, za\u010dne pomalu vrtat. Dlouh\u00fdm rypcem pronik\u00e1 tvrdou slupkou a\u00a0vytv\u00e1\u0159\u00ed \u00fazk\u00fd kan\u00e1lek. Nen\u00ed to pr\u00e1ce na p\u00e1r vte\u0159in. Je to trp\u011bliv\u00e1 \u010dinnost, p\u0159i kter\u00e9 se ukazuje dokonalost milion\u016f let evoluce. Kdy\u017e je otvor hotov\u00fd, ulo\u017e\u00ed dovnit\u0159 vaj\u00ed\u010dko a\u00a0otvor opust\u00ed. Jej\u00ed \u00fakol skon\u010dil. Zbytek p\u0159\u00edb\u011bhu se odehraje uvnit\u0159 \u017ealudu.<\/p>\n
Zvenku nen\u00ed vid\u011bt t\u00e9m\u011b\u0159 nic. \u017dalud d\u00e1l roste a\u00a0dozr\u00e1v\u00e1. Vis\u00ed na strom\u011b mezi stovkami dal\u0161\u00edch. V\u00edtr pohybuje v\u011btvemi, listy \u0161um\u00ed a\u00a0nikdo netu\u0161\u00ed, \u017ee se uvnit\u0159 jednoho z\u00a0plod\u016f vyv\u00edj\u00ed nov\u00fd \u017eivot. Za n\u011bkolik dn\u00ed se z\u00a0vaj\u00ed\u010dka vyl\u00edhne drobn\u00e1 larva. Je b\u00edl\u00e1, beznoh\u00e1 a\u00a0na prvn\u00ed pohled p\u0159ipom\u00edn\u00e1 mal\u00e9 p\u00edsmeno C. Nevid\u00ed sv\u011bt kolem sebe. Nepot\u0159ebuje to. Cel\u00fd jej\u00ed vesm\u00edr tvo\u0159\u00ed \u017ealud. A\u00a0pr\u00e1v\u011b ten se stane jej\u00edm domovem, \u00fakrytem i\u00a0potravou z\u00e1rove\u0148. Larva se za\u010dne \u017eivit v\u00fd\u017eivn\u00fdm obsahem \u017ealudu. Pomalu roste a\u00a0postupn\u011b vypl\u0148uje st\u00e1le v\u011bt\u0161\u00ed \u010d\u00e1st jeho vnit\u0159n\u00edho prostoru. Zvenku p\u0159itom plod \u010dasto p\u016fsob\u00ed \u00fapln\u011b norm\u00e1ln\u011b. Pokud by ho \u010dlov\u011bk roz\u0159\u00edzl, objevil by uvnit\u0159 p\u0159ekvapiv\u00e9ho n\u00e1jemn\u00edka. Dokud ale \u017ealud z\u016fst\u00e1v\u00e1 uzav\u0159en\u00fd, prob\u00edh\u00e1 cel\u00fd proces skryt\u011b. Je to sv\u011bt ukryt\u00fd pod tenkou sko\u0159\u00e1pkou, o\u00a0n\u011bm\u017e v\u011bt\u0161ina lid\u00ed nem\u00e1 ani tu\u0161en\u00ed.<\/p>\n
P\u0159\u00edroda je prost\u011b fascinuj\u00edc\u00ed. Kdy\u017e se proch\u00e1z\u00edme pod duby a\u00a0kouk\u00e1me na \u017ealudy, nem\u00e1me ani pon\u011bt\u00ed, \u017ee pr\u00e1v\u011b v\u00a0nich prob\u00edh\u00e1 \u017eivotn\u00ed p\u0159\u00edb\u011bh mal\u00e9ho brouka. V\u00a0ka\u017ed\u00e9m napaden\u00e9m \u017ealudu prob\u00edh\u00e1 v\u00fdvoj budouc\u00edho brouka. N\u011bkter\u00e9 \u017ealudy obsahuj\u00ed jedinou larvu, jin\u00e9 mohou ukr\u00fdvat v\u00edce jedinc\u016f. Ka\u017ed\u00fd z\u00a0nich \u017eije ve vlastn\u00edm mal\u00e9m sv\u011bt\u011b, odd\u011blen\u00e9m od okol\u00ed tenkou vrstvou d\u0159evnat\u00e9 tk\u00e1n\u011b. <\/p>\n
L\u00e9to se pomalu m\u011bn\u00ed v\u00a0podzim. \u017daludy dozr\u00e1vaj\u00ed a\u00a0za\u010d\u00ednaj\u00ed padat k\u00a0zemi. Pro dub je to obdob\u00ed rozmno\u017eov\u00e1n\u00ed. Pro larvu nosatce \u017ealudov\u00e9ho nast\u00e1v\u00e1 okam\u017eik, na kter\u00fd \u010dekala cel\u00e9 t\u00fddny. U\u017e spot\u0159ebovala v\u011bt\u0161inu z\u00e1sob, kter\u00e9 j\u00ed \u017ealud poskytoval. Vyrostla, zes\u00edlila a\u00a0nyn\u00ed mus\u00ed opustit sv\u016fj dosavadn\u00ed domov. Tehdy vznik\u00e1 ona drobn\u00e1 kulat\u00e1 d\u00edrka, kterou lze naj\u00edt na spadl\u00fdch \u017ealudech. Larva za\u010dne okusovat st\u011bnu plodu zevnit\u0159. Pomalu, vytrvale a\u00a0p\u0159ekvapiv\u011b p\u0159esn\u011b. Nakonec vytvo\u0159\u00ed t\u00e9m\u011b\u0159 dokonale kruhov\u00fd otvor. Kdy\u017e je pr\u00e1ce hotov\u00e1, vysune p\u0159edn\u00ed \u010d\u00e1st t\u011bla ven a\u00a0poprv\u00e9 v\u00a0\u017eivot\u011b spat\u0159\u00ed okoln\u00ed sv\u011bt. \u017d\u00e1dn\u00fd dubov\u00fd les, \u017e\u00e1dn\u00e9 kr\u00e1sn\u00e9 v\u00fdhledy ani romantick\u00e9 podzimn\u00ed barvy. Jen vlhk\u00e1 zem, list\u00ed a\u00a0nekone\u010dn\u011b velk\u00fd prostor ve srovn\u00e1n\u00ed s\u00a0t\u00edm, co znala doposud.<\/p>\n
Pro larvu je to riskantn\u00ed chv\u00edle. Je m\u011bkk\u00e1, bezbrann\u00e1 a\u00a0l\u00e1kav\u00e1 pro mnoho pred\u00e1tor\u016f. Mus\u00ed jednat rychle. Proto se t\u00e9m\u011b\u0159 okam\u017eit\u011b zavrt\u00e1v\u00e1 do p\u016fdy. Tam za\u010d\u00edn\u00e1 dal\u0161\u00ed kapitola jej\u00edho \u017eivota. Mnoho lid\u00ed si mysl\u00ed, \u017ee se b\u011bhem n\u011bkolika t\u00fddn\u016f prom\u011bn\u00ed v\u00a0dosp\u011bl\u00e9ho brouka. Ve skute\u010dnosti m\u016f\u017ee jej\u00ed pobyt pod zem\u00ed trvat mnohem d\u00e9le. N\u011bkter\u00e9 larvy str\u00e1v\u00ed v\u00a0p\u016fd\u011b jeden rok, jin\u00e9 dva a\u00a0n\u011bkter\u00e9 je\u0161t\u011b d\u00e9le. \u010cekaj\u00ed na vhodn\u00e9 podm\u00ednky, p\u0159e\u010dk\u00e1vaj\u00ed zimy a\u00a0postupn\u011b se p\u0159ipravuj\u00ed na prom\u011bnu. Je to zvl\u00e1\u0161tn\u00ed strategie. M\u00edsto rychl\u00e9ho v\u00fdvoje vol\u00ed trp\u011blivost. D\u00edky tomu nen\u00ed cel\u00e1 populace z\u00e1visl\u00e1 na jedin\u00e9m roce. Pokud se n\u011bkter\u00e1 sez\u00f3na nevyda\u0159\u00ed, \u010d\u00e1st jedinc\u016f st\u00e1le \u010dek\u00e1 bezpe\u010dn\u011b pod zem\u00ed. A\u00a0tak se vlastn\u011b z\u00a0jednoho \u00fakrytu dostane do dal\u0161\u00edho.<\/p>\n
Z biologick\u00e9ho hlediska jde o\u00a0velmi chytr\u00e9 \u0159e\u0161en\u00ed. Duby toti\u017e netvo\u0159\u00ed stejn\u00e9 mno\u017estv\u00ed \u017ealud\u016f ka\u017ed\u00fd rok. Existuj\u00ed takzvan\u00e9 semenn\u00e9 nebo mastn\u00e9 roky, kdy jsou stromy obsypan\u00e9 plody, a\u00a0pak obdob\u00ed, kdy je \u017ealud\u016f v\u00fdrazn\u011b m\u00e9n\u011b. Nosatci jsou s\u00a0t\u011bmito cykly \u00fazce propojeni. Jejich \u017eivot je na dubech natolik z\u00e1visl\u00fd, \u017ee zm\u011bny v\u00a0\u00farod\u011b p\u0159\u00edmo ovliv\u0148uj\u00ed i\u00a0jejich populace. Kdy\u017e duby vytvo\u0159\u00ed bohatou \u00farodu, maj\u00ed nosatci ide\u00e1ln\u00ed podm\u00ednky. Kdy\u017e je \u017ealud\u016f m\u00e1lo, za\u010d\u00edn\u00e1 tvrd\u00fd boj o\u00a0ka\u017ed\u00fd vhodn\u00fd plod. P\u0159esto\u017ee se n\u011bkdy ozna\u010duj\u00ed za \u0161k\u016fdce, skute\u010dnost je slo\u017eit\u011bj\u0161\u00ed. Ano, larvy spot\u0159ebuj\u00ed \u010d\u00e1st \u017ealud\u016f, kter\u00e9 by se jinak mohly prom\u011bnit v\u00a0nov\u00e9 duby. Na n\u011bkter\u00fdch m\u00edstech dok\u00e1\u017ee napaden\u00ed v\u00fdrazn\u011b sn\u00ed\u017eit kl\u00ed\u010divost semen. Jen\u017ee p\u0159\u00edroda nen\u00ed jednoduch\u00fd syst\u00e9m, kde by ka\u017ed\u00fd druh m\u011bl jen pozitivn\u00ed nebo negativn\u00ed roli. Nosatec \u017ealudov\u00fd je sou\u010d\u00e1st\u00ed slo\u017eit\u00e9 s\u00edt\u011b vztah\u016f, kter\u00e1 vznikala po tis\u00edce let. Duby, nosatci, pt\u00e1ci, hlodavci, houby i\u00a0dal\u0161\u00ed organismy jsou propojen\u00e9 mnohem v\u00edce, ne\u017e si b\u011b\u017en\u011b uv\u011bdomujeme.<\/p>\n
Mo\u017en\u00e1 pr\u00e1v\u011b proto p\u016fsob\u00ed nosatec tak zaj\u00edmav\u00fdm druhem. Nen\u00ed to dravec, nen\u00ed jedovat\u00fd ani ne\u00fato\u010d\u00ed na \u010dlov\u011bka. A\u00a0p\u0159esto vede zaj\u00edmav\u00fd \u017eivot. Za\u010d\u00edn\u00e1 vysoko v\u00a0korun\u00e1ch strom\u016f, pokra\u010duje uvnit\u0159 \u017ealudu, pak jeho cesta vede pod zem a\u00a0po m\u011bs\u00edc\u00edch \u010di letech kon\u010d\u00ed zrozen\u00edm nov\u00e9ho brouka. To v\u0161e stihne brou\u010dek, kter\u00fd m\u00e1 sotva centimetr. Jeho vzhled nav\u00edc p\u016fsob\u00ed t\u00e9m\u011b\u0159 poh\u00e1dkov\u011b. Dlouh\u00fd rypec d\u00e1v\u00e1 broukovi charakteristick\u00fd vzhled, d\u00edky kter\u00e9mu si ho nelze spl\u00e9st s\u00a0jin\u00fdm druhem brouka. Kdy\u017e se na n\u011bj \u010dlov\u011bk pod\u00edv\u00e1 zbl\u00edzka, zjist\u00ed, \u017ee nep\u016fsob\u00ed odpudiv\u011b. Sp\u00ed\u0161 zvl\u00e1\u0161tn\u011b a\u00a0trochu i\u00a0roztomile. Jako tvor z\u00a0jin\u00e9ho sv\u011bta, kter\u00fd se omylem ocitl mezi b\u011b\u017en\u00fdm hmyzem. Nen\u00ed divu, \u017ee fotografie nosatc\u016f v\u00a0posledn\u00edch letech z\u00edskaly oblibu mezi milovn\u00edky makrofotografie. Teprve p\u0159i velk\u00e9m zv\u011bt\u0161en\u00ed toti\u017e vyniknou v\u0161echny detaily jejich t\u011bla a\u00a0\u010dlov\u011bk si uv\u011bdom\u00ed, jak neuv\u011b\u0159iteln\u011b rozmanit\u00fd je sv\u011bt u\u00a0n\u00e1s existuje.<\/p>\n
Zaj\u00edmav\u00e9 je i\u00a0to, jak m\u00e1lo sta\u010d\u00ed k\u00a0tomu, aby \u010dlov\u011bk jeho p\u0159\u00edtomnost odhalil. Nen\u00ed nutn\u00e9 hledat samotn\u00e9ho brouka. Sta\u010d\u00ed se na podzim pod\u00edvat pod dub. Naj\u00edt \u017ealud s\u00a0malou dokonale kulatou d\u00edrkou a\u00a0uv\u011bdomit si, \u017ee pr\u00e1v\u011b tudy ode\u0161el tvor, kter\u00fd str\u00e1vil v\u011bt\u0161inu \u017eivota uvnit\u0159 semene. Najednou se oby\u010dejn\u00fd \u017ealud zm\u011bn\u00ed v\u00a0d\u016fkaz p\u0159\u00edb\u011bhu, kter\u00fd by jinak z\u016fstal skryt\u00fd. A\u00a0mo\u017en\u00e1 pr\u00e1v\u011b v\u00a0tom spo\u010d\u00edv\u00e1 nejv\u011bt\u0161\u00ed kouzlo nosatce \u017ealudov\u00e9ho. Ukazuje, \u017ee p\u0159\u00edroda nen\u00ed zaj\u00edmav\u00e1 jen tehdy, kdy\u017e naraz\u00edme na vlka, rysa nebo vz\u00e1cn\u00e9ho dravce. N\u011bkdy se nejpodivuhodn\u011bj\u0161\u00ed p\u0159\u00edb\u011bhy odehr\u00e1vaj\u00ed uvnit\u0159 v\u011bc\u00ed, kter\u00e9 ka\u017ed\u00fd den m\u00edj\u00edme. Uvnit\u0159 \u017ealudu le\u017e\u00edc\u00edho v\u00a0list\u00ed. Uvnit\u0159 drobn\u00e9ho sv\u011bta, kter\u00fd je tak mal\u00fd, \u017ee ho v\u011bt\u0161ina lid\u00ed nikdy neuvid\u00ed.<\/p>\n
Nosatec nen\u00ed nejslavn\u011bj\u0161\u00ed brouk Evropy. Vlastn\u011b ho zn\u00e1 jen m\u00e1lo lid\u00ed. Nen\u00ed ani nejv\u011bt\u0161\u00ed, nejbarevn\u011bj\u0161\u00ed nebo nejvz\u00e1cn\u011bj\u0161\u00ed. P\u0159esto pat\u0159\u00ed mezi nejpozoruhodn\u011bj\u0161\u00ed obyvatele na\u0161ich les\u016f. Je d\u016fkazem, \u017ee i\u00a0n\u011bkolikamilimetrov\u00fd tvor m\u016f\u017ee v\u00e9st \u017eivot pln\u00fd p\u0159ekvapiv\u00fdch strategi\u00ed, dlouh\u00e9ho \u010dek\u00e1n\u00ed a\u00a0dokonale na\u010dasovan\u00fdch okam\u017eik\u016f. A\u00a0kdy\u017e p\u0159\u00ed\u0161t\u011b zvednete ze zem\u011b \u017ealud s\u00a0malou kulatou d\u00edrkou, mo\u017en\u00e1 si vzpomenete, \u017ee pr\u00e1v\u011b on byl dlouhou dobu domovem nosatce. <\/p>\n
https:\/\/content.ces.ncsu.edu\/acorn-weevil<\/p>\n
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The Essential Guide to Acorn Weevils: Facts and Insights<\/a><\/p><\/blockquote>\n