Over 400 million years ago, the invertebrates left the seas, evolving on land to dominate every corner of the planet. They now account for approximately 97% of the world’s animals with over 1.3 million species – for every one of us, there are 1.6 billion of them! This January, veteran naturalist Sir David Attenborough explores LIFE IN THE UNDERGROWTH to bring you the amazing stories of its fascinating inhabitants.
In this ground-breaking five-part series, we explore a universe teeming with intricate life that is all around us, yet often invisible to the human eye. Step into the beautiful, strange, ferocious, and super-organised realm of invertebrates. From courtship dances of tiny springtails and worker bumblebees stinging their queen to death, to the world’s largest insect – the monster Titan beetle – and fungus fly larvae that produce twinkling blue bio-luminescent lights, these creatures play an integral role in the land’s ecosystems.
LIFE IN THE UNDERGROWTH premieres 22 January at 9pm (8pm BKK/JKT), with new episodes every Tuesday.
INVASION OF THE LAND
Revealed for the first time - the courtship dances of tiny springtails and the way they can catapult themselves away from danger. These tiny creatures can be found on garden plants, in leaf litter and in gutters but, until now, their amazing acrobatic skills have gone unnoticed as some are only the size of a full stop. Another common garden resident is the leopard slug which has a truly bizarre end to its marathon mating ritual. Both male and female slugs inflate huge blue penises and later lay eggs. Travelling further afield, the rains of South Africa bring out swarms of bright red millipedes to find partners, and, in the caves of Venezuela, giant bat-eating centipedes wait for their meal. Insects can have a softer side to them, too. In one species of Harvestman in Panama it is the males, rather than the females, that take care of the young.
TAKING TO THE AIR
From the stunning aerobatics of hoverflies in an English garden, to the mass migration of purple Crow butterflies in the valleys of Taiwan, this episode tells the tale of the first-ever animals to take to the air. Witness the emergence of mayfly larvae, who begin to fly after having spent two years feeding and growing underwater. They are also in a race against time to reproduce. Dragonflies are some of the most sophisticated of all flying insects, demonstrating supreme control over their aerial movements. Cascade damselflies are found only at a few isolated waterfalls in Costa Rica and Panama and display an extraordinary ability to fly through powerful cascades, seen on film for the first time. Having wings and being able to fly in the last stages of their life gives insects such as butterflies a huge advantage when it comes to finding new breeding sites and sources of food; heavier insects like bumblebees employ a special trick to get them into the air, even on the coldest winter days. Beetles, on the other hand, keep their hind wings well hidden under hard protective wing cases to protect them as they forage for food. Attenborough also finds the world's largest insect, the Titan beetle, a monster of the Amazonian basin.
THE SILK SPINNERS
Silk is the invertebrates' greatest invention. Stronger than a steel thread of the same diameter, but unlike steel, it is elastic and can stretch up to twice its length. From the protective stalks of lacewing eggs to the amazing hanging threads of New Zealand's fungus gnats, invertebrates use it in a huge range of ways. A cave in New Zealand is illuminated by twinkling blue bio-luminescent lights produced by fungus fly larvae but the effect is as sinister as it is truly magical: the glowing blobs attract flies and moths which become snared in the silk to make a ready meal for the larvae. The common wolf spider has no web, but the female is a gentle parent who encases her eggs in a silken bundle which she carries wherever she goes. Then there is the bolas spider that uses a ball of sticky silk coated in a copy of moth pheromone to lure moths in, and the infamous redback spider of Australia which uses silk to 'ping' its prey up into the air where they can be consumed at the spider's leisure. Silk is used by some communal spiders to create silken palaces that can rise 15 to 20 metres up in the forest canopy. Here, millions of tiny spiders work together to kill prey many times their own size. In the United Kingdom, gossamer is the creation of a million baby spiders that spin threads vertically from the top of bushes which will carry them off into the wind, enabling them to travel for miles.
The world of invertebrates is a web of relationships with plants and other animals. In this episode, witness unique footage of one of the world's smallest insects, a chalcid wasp known as a fairyfly. At only a quarter of a millimetre long, the fairyfly glides underwater in search of water beetle eggs to lay its own eggs. In Brazil, the bot fly lays its egg in cattle by catching other species of flies which spend a lot of time hanging around cows. Some insects have the ability to force a plant to make a home for them. In the upper reaches of the Amazonian rain forest are strange areas, sometimes the size of a football field, in which grow only one kind of small tree. The minute Myrmelachista ants 'farm' the particular trees that give them shelter and, in order to make sure they can grow without competition, the ants kill off all other types of seedlings in the surrounding vegetation. Animals of the undergrowth form many mutually beneficial partnerships, but exploitation and deception works just as well. The blister beetle whose larvae huddle together on the end of a piece of grass for example, mimic a female bee to get themselves transported to where they need to be. The blue butterfly caterpillar tricks its way inside an ants' nest where it is fed, cleaned and cared for as if it were one of the queen ant's own brood until it is ready to emerge as a butterfly. One insect is in on this con, however, and uses it to its own advantage.
Every insect society is full of conflict, power struggles and mutinies. The sand wasp works hard to look after its young but the female is too busy to guard all her nest sites. Paper wasps in Panama, on the other hand, have learnt to group their nests together. The female wasp employs her sisters to look after her eggs. Bees are renowned for their colonies but these colonies are rife with tension. For the first time, cameras have filmed the worker bumblebees turning on their queen and stinging her to death, behaviour that has only recently been discovered. See how Giant Asiatic Honey Bees protect their honey, defending their nest with some dramatic displays. Ants have learnt to work together to kill prey much bigger than themselves and protect their nests from attack. But when it comes to creating a permanent home for the colony, termites are the champion. Their mounds are complex architectural creations with their very own air-conditioning system - but nothing can protect them from the vicious attack of Matabele ants.