Tiny terrors
Grisly horror film with a bloodthirsty plot, or just another bug-eat-bug day in the undergrowth? Gail Ashton shines a light on the brutal world of our carnivorous mini-beasts
If you think you need to go to the far reaches of the planet to see savage animals, then I have news for you. Some of the most ferocious battles and gruesome deaths are happening right under our noses, in the fields, woodlands and clifftops of the UK.
In every part of our countryside, tiny creatures face a day-to-day battle for survival as they fly, scurry and dig their way out of the path of terrifying predators. Seemingly peaceful wetlands, woodlands and nature reserves are anything but, when you zoom in on the microhabitats within them. Rather than a dog-eat-dog world, I would argue that it is, in fact, a bug-eat-bug world. I’ve never seen a dog eat another dog, but I have seen lots of invertebrates dining on each other.
Our countryside is full of mini assassins in the form of familiar species, such as beetles, wasps and spiders, and also lesser-known predators, such as lacewings. Flies and true bugs have got hunting down to a fine art, equipped with an array of specialist weaponry that, on a human-scale, would create nationwide panic. Ground beetles have large, powerful jaws and an impressive turn of speed to chase and grab prey. Carnivorous true bugs impale their quarry with a long pointy rostrum, liquify their innards and suck them dry. Some flies and beetles purée the insides of snails to procure a healthy meal.
Dragonflies rule not only the skies but the depths too: their larvae lurk at the bottom of ponds, picking off passers-by with lightning-fast reflexes and an articulated jaw not unlike the xenomorph in the Alien films. Then there are the parasitoids that slowly consume their prey alive.
ECOSYSTEM EQUILIBRIUM
This is all normal invertebrate behaviour. Millions of years of mutual carnivory have gradually settled into a delicate coexistence, in which predators control the numbers of planteating species, creating a balanced ecosystem.
These tiny terrors of the countryside are more helpful to us than we can possibly comprehend. If we want to keep enjoying our natural landscape, we need to take care of these essential beasts, so they can continue to shape our land for many more generations to come.
You can see amazing predators everywhere: find robber flies and dragonflies hunting in grass and heathland. Look at the flowers of hemlock, cow parsley and wild carrot for solitary wasps and crab spiders.
Open paths are perfect for observing predatory ground beetles and parasitoid wasps in search of the nest holes of their hosts. Enjoy your quest to find our tiny terrors!
1. WASP SPIDER
Argiope bruennichi
A late-summer walk in long grassland is a great opportunity to spot the wasp spider. It’s large, almost 2cm long (not including legs), with vivid yellow, white and black stripes across the abdomen. Wasp spiders primarily eat grasshoppers, and so are less likely to be found in more manicured urban areas. They are not easy to spot initially, so tread carefully so as not to damage the beautiful webs, made using a zigzag construction called a ‘stabilimentum’. Their large, brown, bauble-like egg sacs can also be seen hanging off grass stems.
2. RUBY-TAILED WASP
Family Chrysididae
Some of our most efficient insect hunters aren’t the fastest or fiercest, but the sneakiest. The ruby-tailed wasp is similar to the cuckoo: just like the bird, it lays its eggs in the nests of other species, in this case other solitary wasps. It tracks down the nest of a potential host, creeps into the entrance, finds the egg and deposits its own alongside. In a macabre twist, the emerging ruby-tailed wasp doesn’t eject the other egg, it eats it, and all the food stored in the nest. Photos: Naturepl.com
3. DAMSEL BUG
Family Nabidae
Damsel bugs are feisty beasts that eat aphids, bug nymphs and other soft-bodied, slowmoving invertebrates that cannot outrun them. Once in its grip, the damsel bug inserts its long, needle-like mouthparts into the prey, sucks out the innards and discards the desiccated carcass. Aphids are often farmed by ants, who love the taste of their sugary ‘poo’, known as honeydew; the ants will fiercely defend this valuable food source. Ant damsel bug nymphs (Himacerus mirmicoides) look very similar to worker ants, which may be a cunning mechanism to blend into the colony and sneakily feast on the farmed aphids.
4. GREEN TIGER BEETLE
Cicindela campestris
The green tiger beetle is one of our most formidable hunters, stalking and ambushing its prey, much like its feline namesake. The most striking feature of this beetle is its marvellous metallic green body, with pink tinges and white spots on the wing casings. Close up, you can see huge eyes that give it excellent all-round vision, long legs that enable it to move with lightning speed, and deadly jaws, which will be the last thing you see if you are unlucky enough to be its prey.
5. PARASITIC FLY
Phasia hemiptera
We tend to think of flies as being scavengers, but some are also prolific predators. Phasia hemiptera is a parasitic fly that uses green shieldbugs as hosts. The female lands on the substantially slower shieldbug and lays her eggs on its surface, then flies away, job done. The resulting larva emerges on to an all-you-can-eat buffet, burrowing into the bug to consume it from the inside. The fly larva even know to eat around the shieldbug’s critical organs, to keep it alive and fresh for longer.
6. ROBBER FLY
Family Asilidae
You might think that birds of prey are the supreme hunters of our countryside, but here’s an insect that can more than match our raptors’ credentials. Robberflies have mastered the art of aerial hunting, which they perform with clinical efficiency. They hunt a variety of prey – including hoverflies, grasshoppers and moths – which they consume by piercing and paralysing them, then sucking them dry with hypodermic mouthparts. Robberflies can be identified by their long, slender bodies, powerful legs with short, spiny hairs and their impressive facial hair.
7. LACEWING LARVAE
Order Neuroptera
The vampire-like larvae of lacewings are truly fearsome. They look a bit like short, dumpy caterpillars, but with the addition of frankly terrifying pincers. These long, curved appendages are used to grab prey. They rumble through the vegetation like mini-tanks, devouring anything in their path, particularly aphids. As if that isn’t scary enough, lacewing larvae are known to decorate themselves with the remains of their victims; they plaster themselves with dehydrated corpses, presumably to fool their prey into thinking that they aren’t about to be eaten.
8. POTTER WASP
Ancistrocerus sp
The potter wasp has highly tuned senses. It can locate a caterpillar hidden inside a plant stem, whereupon it extracts it with surgical precision. It paralyses the larva, then flies off with it, hugging it under its body. Once back at the nest, it stuffs the larva into its nest cell, where an egg lies incubating. The paralysed caterpillar remains alive as the emerging wasp larva proceeds to feast upon the helpless grub.
9. FLOWER CRAB SPIDER
Misumena vatia
Imagine being so good at camouflage that your food practically lands in your mouth. The female flower crab spider has perfected the art of blending in. She will find a suitable flower, sit on top of it, with her rear against the petals, leaving the nectar and pollen parts fully accessible. She then proceeds to slowly colour-shift (often to white or yellow) until she is barely visible, and waits. When an oblivious flying insect lands just in front of her, she lunges forward with super-fast reflexes, then slowly devours her victim.
10. EMPEROR DRAGONFLY
Anax imperator
Life on the water’s edge is perilous for any insect if the emperor dragonfly is around. Its four, highly adapted wings work independently of each other, enabling it to accelerate to around 30mph then turn with startling speed and precision to catch flying insects. The emperor dragonfly patrols a wide area to hunt, so you may spot one some distance from water, in open grassland.
Once up and about, it rarely lands again until bedtime, but if a prey item is too much of a ‘mouthful’ to eat on the wing, it will briefly land to finish its meal.
Gail Ashton is a photographer, writer and illustrator with a passion for invertebrates.
She is co-author of An Identification Guide to Garden Insects of Britain and North-West Europe (John Beaufoy, £14.99).