ENDANGERED/EXTINCT SPECIES/ ESSAY

Let’s talk about sex

It’s a shame that one can’t observe the courtship ritual of Saint Helena Island’s (SHI) earwig. Because within this bug group, courtship is a surprisingly elaborate affair.

First, the male taps and strokes a female’s abdomen with his forceps. The female nibbles the forceps, where a chemosensory component may help the female to decide if she’ll accept the suitor or not.

The female takes her time to decide. Ten minutes, in fact. If she accepts, she’ll close her forceps and raise her abdomen to a mating position. Let’s hope the male hasn’t lost his inner skill for contortionism, as he twists his abdomen by 180 degrees so that the bottom of his abdomen faces up. Next, they couple. And they’ll stay that way, in that same position, for several hours. This is marathon mating.

The male has enormous, rod-like genitalia, called viagra, no, virga. The virga is the size of the length of its body, and twice as long as the female’s, in some species. We’d really like to know about what sex was like with the extinct, largest earwig in the world, the SHI earwig. Maybe it’s all that, and more.

A male earwig’s genitals are multi-purposed, depending on the species. Some species can inseminate, and also clean out sperm from other males that had mated with the female before him. Another male earwig species has two virgas. One might get cut off while he’s penetrating the female. No worries. True, half of his virga is still in the female, but he has a spare virga that works just as well, all circumstances considered.

A mother’s love

How far would you go for your children? Human mothers would generally give their own lives to protect their young. What about insects?

It depends on the insect species. But Dave Clark of the London Zoo said that the extinct, female Saint Helena earwigs (Labidura herculeana) were “extremely good mothers.”

This is atypical behavior of non-social insects like earwigs. Normally, non-social insect mothers deliberately create distance between themselves and their young.

Some 2,000 earwig species globally are very maternal, as was the extinct St. Helena Island (SHI) giant earwig. However, some are more maternal than others. Some will sacrifice themselves for their young.

Protection

A mother earwig regularly cleans her eggs. She does this to remove harmful fungi. At the same time, she applies an antifungal chemical to the egg.

When the eggs hatch, the mother helps the larvae out of its shell. She also feeds her nymphs regurgitated food and lays on top of them to keep them warm and safe.

If a predator attacks, the earwig mom will leave their nest to give the predator a taste of mom power. For months after, she continues to protect her young.

Earwig Moms will stay with their nymphs until they’ve molted twice. This is true of every earwig species that’s been studied.

Over mothering

In the insect kingdom, does over-mothering exist? One can’t be sure, but the interaction of nymphs and mom can be quite compelling, sometimes.

But can we judge the activity of earwigs from a human behavior scale? Let’s take it as it is. The hump earwig nymphs, for example, when they’re of age, will eat mom. That makes them strong enough to go off on their own and live independently. This may be why Clarksaid, “I love all insects, particularly earwigs. They’re fascinating.”

One wonders how far the Saint Helena earwig went for its nymphs. As the world’s largest earwig, eating mom would be like having a fiesta.

But we’ll never know because they’re now extinct. We’ll never see a live, shiny black bug with reddish legs that can fit in the palm of one’s hands.

The wingless SHI earwig doesn’t have the diaphanous, unfurling, fan-like delicate wings of other earwigs. These wings stretch 10 times their folded size, enabling flight. Then they fold back up, like a fan, very quickly. The sight leaves one breathless.

But what the SHI earwig lacks in wings, it compensates for as the (former) largest living earwig in the world, and it had a beautiful black body that shone.

Habitat

The SHI earwig’s only home was this island, where it inhabited the Eastern Arid Area, Horse Point Plain, Prosperous Bay Plain, gumwood forests, and seabird colonies in rocky places.

The earwig lived beneath a cozy stone, close to deep burrows that doubled as escape routes. In both the rainy and dry seasons the SHI earwigs slept underground, and came out at night, after the rains, to seek food.

A Remote Island

St. Helena Island is one of the most remote islands on the planet. Its rich biodiversity is home to rare spiders that have yet to be named, and beetles that humans only learned of in 2005. Many birds are endemic to this island. This is why some naturalists rank SHI in the same league as the Galapagos Islands.

Today, there are  6,123 people who live on SHI. It’s a mountainous yet bare volcanic island. The sky is grayish, but sometimes, from a distance, you’ll see green peaks.

There are many theories of who discovered St Helena Island, and when. But the generally accepted story is that St. Helena island was totally uninhabited when it was discovered by the Galician navigator João da Nova on May 21, 1502. Da Nova gave the island its name because the 21st was the feast day of St Helena of Constantinople.

In the summer whale sharks pass through on their annual journey to their eventual seasonal pit stop. They stay a while, enjoying the plankton, which isn’t far from the shore. Visitors see these huge, beautiful, and meek creatures. They may even swim alongside them, but they must keep a responsible distance away.

This is the island that had been the home of the SHI giant earwig, a remote isle in the Southern Atlantic, lying between South America and Africa, and rich in hundreds of endemic species, of which they were once a part. The SHI earwig wasn’t saved, but let that be a cautionary tale regarding other endemic species that need protection, and that are only found here.

SHI people are called “Saints” for short. They are a very friendly and caring community that enjoys a rural lifestyle amid a peaceful, beautiful island backdrop. Their culture is a mesh of British settlers, Chinese, East Indies, Madagascar, employees of the East India Company, and indentured laborers from the South Asian subcontinent. SHI is also famous as the place where Napoleon Bonaparte stayed in exile until he died in 1821. Today, it’s a British Overseas Territory.

Extinction

The St. Helena earwig was first mentioned in 1798 by Danish scientist Johan Christian Fabricius, a student of Carl Linnaeus.

However, the SHI earwig was confusing to entomologists and was included with smaller earwig species. It soon lost the attention of scientists and was neglected.  The insect was last seen alive in the wild in 1967, but body parts had been found up to 2014. Sadly, it’s believed that these parts are from individuals that had died decades ago. Below is a timeline of the SHI earwig’s extinction:

  1. 1798. The SHI earwig was first described by Danish Entomologist Fabricius.

  2. 1913. Babault collected SHI earwig specimens.

  3. 1959. More specimens were found by Douglas Dorward and Philip Ashmole with bird bones at Prosperous Bay, on the eastern coast of St. Helena Island.

  4. 1965. Some 40 specimens were gathered at the Horse Point area by two Belgian expeditions from the Royal Museum for Central Africa. This would be the last time a St. Helena Earwig was spotted alive.

  5. 1970. Dr. Leleup found dead specimens which he wrote about, as well as the island’s biodiversity, climate, fauna, geology, etc. in a four-volume book.

  6. January 4, 1982. The SHI Philatelic Bureau issued a commemorative stamp depicting the earwig which brought attention to its conservation.

  7. 1988 and 1993. Scientists sent two expeditions under Dr. Paul Pearce-Kelly, currently a trustee of the Zoological Society of London, but they didn’t find the SMI earwig.

  8. April 1995. A specimen of earwig remains were found, namely sub-fossil forceps and an abdominal target with bird bones. It proved that the earwigs not only lived in gumwood forests before breeding seabirds but were wiped out by introduced predators. They also lived in seabird colonies in rocky places.

  9. 2000 to 2003. Neither specimens, nymphs, nor fossil cercis were found.

  10. 2005 to 2006. Howard Mendel from the Natural History Museum in London also searched and found nothing.

Finding the SHI earwig shouldn’t be hard, because its adults and nymphs are large, and they occupy a single habitat.

Because of this, by 2014, the International Union for Conservation of Nature (IUCN) declared the St Helena Earwig extinct, adding, “The habitat…has been degraded as far as this species is concerned… by the removal of nearly all surface stones, under which specimens were then found, for construction purposes”.

Causes of extinction

  1. Soil erosion. Soil erosion became widespread when settlers cleared native plants and used ground rocks (where earwigs hid) to build homes. This left the SHI earwigs with little to no protection.

  2. SHI earwig habitat at Horse Point was degraded. By 1965 – 1967 most surface stones were removed and repurposed for construction. Some humans liked to collect stones.

  3. Gumwood forest, in Horse Point Hill, was home to many SHI earwigs, but this habitat was also cleared for human use.

  4. Introduced animals preyed on the SHI earwigs such as:

  • The centipede Scolopendra morsitans, is an insatiable predator. It is likely that it hid in boats from the Mediterranean.

  • Animals. Cats, goats, mice, rats, sparrows, spiders, mantids and predatory invertebrates feasted on the SHI earwig.

  • Predator extinct. One of the SHI earwig predators, the Giant Hoopoe, Upupa antaios, is also now extinct

The importance of insects

The SHI Earwig lived in deep burrows underground. At night they emerged to eat rotting vegetation, in this way they were cleaners of the forest floor, helping to keep its ecosystem hygienic. Though mostly found in rocky areas, it was also seen in forests and seabird colonies. The SHI earwig was herbivorous, but it’s possible that it was also omnivorous.

Why bother writing about an extinct insect? First, one never knows if the insect will turn up elsewhere. But once it’s declared extinct, scientists will stop looking for it. They’ll have to accidentally bump into an SHI earwig to discover that it still lives.

Earwigs also did their share in keeping an ecosystem balanced both as janitor and prey. But when introduced species were brought in, the balance was upended.

Insects are the pinions that keep the delicately tuned ecological machine in balance, but through a combination of temperature change, habitat destruction (gravel mining by humans for building), and modern agricultural practices, we are losing many of our insect species.

Humankind needs insects in order to survive. They’re crucial decomposers that help to break down and dispose of wastes, dead animals, and plants. They are also pollinators and play an essential role in the food web. However, according to the latest scientific global review on biodiversity, more than 40% of insects are declining and a third are endangered.

How people can help insects

We don’t want insects in our homes, especially if they’re disease carriers or they’re munching on our homes’ foundations. We can live with insects by doing the following:

  1. Plant gardens. They’re vital for wildlife. Gardens can:

  • Provide green corridors between open countrysides.

  • Permit movement of insect species.

  • All the gardens in the world put together will create more space for nature and wildlife than all the National Nature Reserves put together.

  • Attract birds, mammals, and invertebrates into your backyard, but only if you fill your garden with native plants and trees.

It can’t hurt to share important living space so that many living creatures can survive. When we help them, they help us back. It’s all part of nature.