第1782期:When you're an ant but also a fungus tycoon

In this south Texas clearing, an ancient tale that ties the members of four species together is unfurling. The first involved is our soon-to-be queen leafcutter ant. The second is this fungus, a piece of which she scoops into her mouth pocket. The third are these tiny cockroaches, which nestle under her wings. And the fourth is the one that threatens them all. But it’ll reveal itself later.

在得克萨斯州南部的这片空地上，一个将四个物种的成员联系在一起的古老故事正在展开。第一个涉及的是我们即将成为蚁后的切叶蚁。第二种是这种木耳，她舀了一块放进嘴里的口袋里。第三种是这些小蟑螂，它们依偎在她的翅膀下。第四个是威胁他们所有人的那个。但它会在稍后显露出来。

In a flapping-wing frenzy, our ant takes to the sky. This is the only chance she’ll have to mate, so she stores as much sperm as she can from the males she meets in midair. After dropping to the ground, she sheds her wings and begins digging. She excavates a tunnel and a side chamber, then plugs the entrance, sealing herself in. There, she regurgitates the fungus. This pile of puke will form the bedrock of her kingdom. Over the following weeks, in between laying eggs and consuming the infertile ones, she tends to her developing fungal garden, fertilizing it with feces.

在扑翼的狂热中，我们的蚂蚁飞向了天空。这是她必须交配的唯一机会，所以她会尽可能多地储存她在半空中遇到的雄性的精子。掉到地上后，她脱落了翅膀并开始挖掘。她挖出一条隧道和一个侧室，然后塞住入口，将自己封闭在里面。她在那里吐出真菌。这堆呕吐物将构成她王国的基石。在接下来的几周里，在产卵和吃掉不育卵之间，她照料着她正在发育的真菌花园，用粪便给它施肥。

Finally, her first offspring surge forth and establish a rhythm. Soldiers guard the nest while foragers set off to find tender foliage. The larger foragers, equipped with powerful mandibles, anchor themselves on leaves and chomp away in a wide arcs. Holding these pieces aloft, which can weigh more than eight times their body mass, the workers march back to the nest. Meanwhile, the colony’s smallest ants clean the leaf fragments of debris and pathogens.

最后，她的第一批后代涌现并建立了节奏。士兵守卫巢穴，而觅食者则出发寻找嫩叶。较大的觅食者配备了强大的下颌骨，将自己锚定在树叶上并以宽阔的弧线咀嚼。工人们将这些重量超过其体重八倍的碎片举到高处，然后返回巢穴。与此同时，蚁群中最小的蚂蚁清理叶子碎片和病原体。

But the colony doesn’t eat these morsels. Instead, the ants use them to sustain their fungus, which, in turn, sustains the colony. More than 10 million years ago, leafcutter ants domesticated fungus. Like many of our crops, the fungus they farm is genetically distinct from its wild relatives and can no longer survive without their help. Reciprocally, the fungus provides the ants with an essential amino acid and digestive enzymes they’ve lost. Once the workers return to the nest with their spoils, they crush up the leaves, making their offerings easier for the fungus to consume.

但是殖民地不吃这些食物。相反，蚂蚁用它们来维持它们的真菌，而真菌反过来又维持了蚁群。超过 1000 万年前，切叶蚁驯化了真菌。像我们的许多农作物一样，他们种植的真菌在基因上与其野生近缘种截然不同，没有它们的帮助就无法生存。相反，真菌为蚂蚁提供了它们失去的必需氨基酸和消化酶。一旦工蚁带着他们的战利品回到巢穴，他们就会把叶子压碎，使他们的祭品更容易被真菌吃掉。

Foragers work tirelessly over the following months. They create thousands of trails, stretching hundreds of meters. All of them are perfumed with the ants’ pheromones and constantly cleaned to function as efficient highways. Meanwhile, the queen lays thousands of eggs every day and is tended to by members of her entourage, which nourish her with the large, infertile eggs they lay.

在接下来的几个月里，觅食者不知疲倦地工作。他们创造了数千条小径，绵延数百米。所有这些都散发着蚂蚁信息素的香味，并不断清洁以发挥高效高速公路的作用。与此同时，蜂后每天产下数以千计的卵，并由她的随行人员照料，这些随行人员用它们产下的大而未受精的卵来滋养她。

Among enclosures containing garbage and growing larvae, workers tend fungal gardens in various chambers throughout the colony. They prune bits of the fungus to stimulate growth and strategically open and close surface tunnels, controlling the humidity.

在装有垃圾和正在生长的幼虫的围栏中，工人们在整个蚁群的不同房间里照料真菌花园。他们修剪部分真菌以刺激生长，并有策略地打开和关闭地表隧道，控制湿度。

But ants aren't the only animals down here. Tiny cockroaches like those that originally crept under the queen’s wings feed opportunistically off the fungus. Each could fit on the head of a Q-Tip. They hitch rides on soon-to-be queens, and make their way to more established colonies. Inside the leafcutter nest, they’re undercover: closely mimicking the ants’ signature scent, they frolic and feed in the fungal gardens, mostly undetected.

但蚂蚁并不是这里唯一的动物。像那些最初爬到蜂后翅膀下的小蟑螂，机会主义地以真菌为食。每个都可以装在 Q-Tip 的头上。他们搭上即将成为女王的便车，前往更成熟的殖民地。在切叶蚁巢内，它们是卧底：模仿蚂蚁的标志性气味，它们在真菌花园里嬉戏和觅食，大部分都未被发现。

And here’s where this tale’s antagonist rears its virulent fruiting body: our elusive fourth character is a parasitic micro-fungus called Escovopsis. If left unchecked, it would destroy the fungal gardens and the ants and the cockroaches that depend on them. The leafcutters mount a barrage of defenses. They rigorously weed Escovopsis out and partner up with different microorganisms like yeasts and bacteria to stunt its growth.

这就是这个故事的对手养育其有毒子实体的地方：我们难以捉摸的第四个角色是一种叫做 Escovopsis 的寄生微型真菌。如果任其发展，它会摧毁真菌花园以及依赖它们的蚂蚁和蟑螂。切叶蚁发动了一连串的防御。他们严格除草 Escovopsis 并与酵母和细菌等不同微生物合作以阻碍其生长。

Eventually, the leafcutter colony covers several meters of underground tunnels, comprises millions of workers, and can defoliate a tree in a single night. The queen’s kingdom will persist as long as she does, which may be over a decade. Every spring, some of the queen’s offspring prepare to leave. They grab a piece of home and crowd the surface chambers, preparing to fly off and mate, beginning the cycle anew.

最终，切叶蚁群落覆盖了数米长的地下隧道，由数百万工人组成，并且可以在一夜之间将一棵树的叶落尽。女王的王国会一直存在下去，可能会持续十年以上。每年春天，女王的一些后代都会准备离开。他们抓住一块家，挤在表面的房间里，准备飞走交配，开始新的循环。