You pick up a rock and look up to see a tiny insect with its tail curled up and ready to pounce on anyone it knows. Then you will see the servants – small white insects, piled at the bottom. Do you throw the stone and crush them or leave them alone?
What you’ve got is a family belonging to one of Britain’s best-loved, but most thought-provoking insects – the earwig.
Only 1% of insect species show parental care. Earwigs are one of them.
Females make an underground chamber, lay 30 to 60 eggs and protect them from fungi by “licking”. If a mole or other flying animal scatters her eggs, she will diligently collect them again.
They hatch after 70 days, usually at the end of winter. Foraging in winter is dangerous when predators are more hungry than usual, but the mother helps her cubs survive to adulthood because they stay in the safety of their den until they grow up.
At the end of spring, the baby “wiglets” are dispersed. The female may have a second, smaller brood with fertilized eggs from the first pair.
Maternal empathy appears to be built into earwig genes, as artificially raised wigglets later show care for their own young. Caring parents take the opportunity to pass on their genes, despite the energy costs.
In contrast, there is a type of wasp that encloses its eggs in a nest with only enough food for a few larvae, where the stronger ones eat their siblings. This is parental provision rather than parental care.
Smart wings
The ears are unusual in other ways. They are members of the order Dermaptera (“skin-winged”), which refers to their short, leathery forewings, also called tegmina. These protect the rear wings covered with a membrane. Grasshoppers, stick insects and cockroaches have leathery wings.
Earwigs respond to touch, known as positive thigmotaxis, so they are typically attracted to enclosed spaces. To adapt to this behavior, their hind wings fold under the tegmina. The name “ear wig” can come from their ear-shaped rear wing, which is very intricately folded, and has been studied for engineering solutions from self-folding tentacles to space flight.
The word “earwig” comes from the Old English ‘ēare’ (ear) and ‘wicka’ (insect). Many types of insects, including flies, moths, and crickets, enter people’s ears and should be carefully removed.
But you won’t be bored in your mind by the sad stories of your older brothers or classmates. Earwigs may enter a person’s ear because they prefer close contact, not because they want to do you any harm.
When you consider the fact that human activity has destroyed so many animals, nature is in danger of collapse, the idea that these animals are dangerous is ridiculous.
It’s not just for show.
The most distinctive feature of European ears is their terminal power. Powers are used for protection, to weaken predators, and in mating rituals. The knees are straight in women and curved in men.
They also differ between men. Those with shorter, strongly curved knees are called brachylabic. Men with long straight knees are called macrolabic. Macrolabic males are more successful at mating and interrupt subsequent processes involving less skilled earwigs.
One study examined the relationship between device size and the effectiveness of the earwig’s immune system. Forced volume was found to correlate with hemocyte concentrations. In insects, hemocyte cells are critical for preventing infection. Brachylabic males produce more hemocytes when infected with bacteria than macrolabic earwigs.
Like us, earwigs can be a social gathering. In autumn, they release a pheromone that attracts other earwigs. This is mainly for mating, but earwigs are collected during hibernation, just like ladybirds. Nymphs ? They produce pheromones to encourage maternal care.
Dating involves energy. The males wave them in the air and use them to strike and catch the female, but they are not used for mating. It may take several hours for the mating pair to transfer sperm from tail to tail.
A man and a woman can have many partners. They may stay together after the female burrows and lays her eggs, but the males usually return to forage, so don’t feed their wiggles.
Are earplugs good or bad?
They carry no known human pathogens, but can use their energy to deliver small amounts of milk. Sometimes they are garden or vegetable pests. They damage plants, especially dahlias, lettuce, strawberries, potatoes and roses.
But earwigs also benefit us. As consumers of organic matter, they accelerate decomposition in compost. Natural pests are controllers, and aphids, termites, and insect larvae feed on plants. If you want to keep your distance, they can be controlled with moisture, rolled newspaper, or non-chemical methods, diatomaceous earth (a natural stone that can be broken down into a fine white powder).
Earwigs enter homes through cracks and crevices and can gather in damp rooms, closets or bathrooms using a pheromone. But they do not harm your home and do not breed at home.
They show the importance of maternal care and biological trade. They can best help us design structures that fit into small spaces but unfold into something larger.
Perhaps people’s aversion to earwigs is similar to the reaction of ants when you pick up a rock and find a colony that burns. Some researchers believe that overpopulation threatens the human need for individuality and independence.
Here they are interrupting a mostly peaceful family life, when mom and the wiggles are suddenly struck by light. Turn the stone carefully. They want to be left alone as you do.
This article is reprinted from the discussion under a Creative Commons license. Read the original article.
Christopher Terrell Nield does not work for, consult with, own stock in, or receive financial support from any company or organization referenced in this article, and has disclosed no relevant affiliations beyond his academic appointment.