Agriculture is often viewed as the basis of human civilization. But there are some other — rather unlikely — farmers out there in the animal kingdom.
Image: Imago/blickwinkel
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From ancient Egypt and China to the Babylonians and the Olmecs: agriculture played a key role in the development of human civilization all around the world. At first glance, the cultivation of food would seem to be a uniquely human trait. But as it transpires, there are other animals out there who grow their own food too.
Perhaps surprisingly, they aren't the most intelligent or highly developed species in the animal kingdom. You'd be hard-pressed to find a chimp, dolphin or elephant farming their food. But you will find thousands of bug species that do.
A case in point are the ambrosia beetles. There are about 3,000 different known species of these bugs but they all have one thing in common: their symbiotic relationship with their sole source of nourishment, the ambrosia fungi.
So what does all this have to do with agriculture? Well, the modus operandi of these bugs, which are often only a few millimeters in size, is to dig tunnels in the wood of sick or dead trees.
Once their galleries — as these tunnels are called — are established, the insects sow the spores of ambrosia fungi. The bugs carry these spores in specially-adapted compartments on their bodies known as mycangium.
Ambrosia beetles can be tiny, often just a few milimeters. But they are avid gardenersImage: Imago/blickwinkel
The fungi take root and grow, extracting nutrients from the wood. Meanwhile, the insects tend to their fungal crop like careful gardeners, even controlling the tunnels' humidity.
The bugs feed on the fungi, which in turn rely on the beetles for transport to new suitable habitats and favorable living conditions. When the beetle larvae are all grown up and ready to venture out into the world on their own, they gather as many spores as they can carry to seed a fungal garden in a dead tree of their own.
Beetle and fungus: neither has ever been found anywhere without the other.
This may all seem quite exotic, but ambrosia beetles are far from alone in their passion for gardening. Leafcutter ants grow fungi as well, as do some termites — although, unlike the ambrosia beetle, none live exclusively from their crop.
And in case you still think we humans were incredibly innovative when we started growing crops and domesticating animals some 10,000 to 15,000 years ago, consider the termite. These insects have been growing fungi for a whopping 31 million years. Kind of humbling, isn't it?
Beneficial bugs - life wouldn't be the same without them
Insects can be annoying. They can even make you ill. But a lot of bugs are incredibly useful - they provide use with things to eat, they keep the planet clean and protect us from danger.
Image: Robert R. Jackson
Can't live without them
They eat aphids and mosquitoes. They pollinate fruit trees and vegetables. They even dispose of trash. If you could only let yourself get close enough, you might discover how beneficial insects can be.
Image: Iryna Novytsky
Busy little helpers
The best known example of a beneficial bug is the bee. Not only do they produce honey, but without their ability to pollinate, trees and plants would be virtually fruitless. But bees are an endangered species - worldwide. In some parts of China they are already extinct. Pesticides and mites are to blame.
Image: picture-alliance/dpa
Loveable greedy guts
Ladybugs tend to mainly eat aphids and scale insects. Perhaps that's why we love them so much. One ladybug eats about 50 such insects a day - and many thousands over its entire lifetime.
Image: Fotolia/ K.-U. Häßler
The benefits of ladybug larva
Its eating habits mean the ladybug is also highly-prized in pest control. They are popular with farmers, who use ladybugs to control aphids and scale insects without the need for chemicals. Even its larva helps in the fight against pests.
Image: cc/by/sa/Martin Eberle
Parasite on parade
Scorpion wasps are absolutely harmless for humans. But for some insects, a meeting with a scorpion wasp can end horrifically. The wasp is known to insert - or drill - its large ovipositor (an organ used for laying eggs) into moths, beetles and lice, where it lays an egg. The egg becomes a larva and the hungry larva then eats the insect from the inside out.
Image: cc/by/sa/Panox
Remarkable predator
Ground beetles are predators. They tend to hunt all the things we don't want: woodlice, caterpillars and slugs. Even the nimble and resistant potato beetle stands little chance against the ground beetle's strong jaws. They are found all over the world - but many are a protected species.
Image: cc/by/sa/Soebe
Dark crawler
This is a beetle - even if it looks like a worm at first. The rover beetle has very short wing cases (elytra), which hold intricately folded wings. Worldwide, 50,000 variations of the rover beetle are known to exist. They like to eat bark beetles and fly maggots, but will also tuck into dead animals and the remains of plants.
Image: cc/by/sa/Hedwig Storch
Friendly giant
Hornets command respect - but their poison is less dangerous than a common wasp. The grown-ups prefer to sup the juices of plants, while the young feed on all kinds of fresh meat: they can catch up to 500 grams of insects per day.
Image: cc/by/sa/Flugwapsch62
The best till last…
… spiders. Given their eight legs, spiders aren't strictly speaking insects … but they are still very useful. They catch and eat every kind of insect that's annoying to us. Mosquitoes, moths, flies, and aphids are all a delicacy for spiders.
Image: C.M./Fotolia
So let them live
Don't be scared, don't step on them, or reach for your nearest rolled-up newspaper. Just be happy they're there!
