You might not think that tiny brown specks in a sand box would be something to get excited about, but for entomologists at the San Diego Zoo, these small textured spheres are an exciting new chapter in one of the most thrilling stories of animal conservation. They are the freshly laid eggs of one of the world's rarest bugs: the Lord Howe Island stick insect.

These big bugs can grow to be at least 12 centimetres (around five inches) long, but despite their impressive size, they're harmless plant-eaters, with no wings and a habit of waiting for dark to go foraging. At the San Diego Zoo, they live in groups of about 15, in habitats with cozy logs for them to curl up in during the day, and sandy areas for the females to lay eggs.

The zoo is home to around 70 adults in total, but that number is about to rise: roughly 500 eggs (which look impeccably like tiny seeds) were laid this fall, marking the first time this species has produced eggs in a North American facility! It's an exciting achievement, considering that just 13 years ago, the only zoo to successfully breed these insects was the Melbourne Zoo in Australia. And just five years before that, the species was thought to be extinct.

As their name implies, these bugs were once native to Lord Howe Island, which lies in the Tasman Sea between Australia and New Zealand. In 1918, a ship ran aground on the island and inadvertently dropped off a load of black rats, which seem to have made quick work of the big, juicy stick bugs. After 1920, the insects were seen no more.

Then, in 2001, came an incredible discovery. Scientists from the New South Wales Government Office of Environment and Heritage followed a rumour to another island called Ball's Pyramid, a tall chunk of volcanic rock located about 23 kilometres southeast of Lord Howe. There, alive and well, a couple dozen stick insects were hiding out in the short shrub.

With its steep cliffs and barren vegetation, Ball's Pyramid looks like the kind of spot a supervillain might choose for a deep underground lair. There's no place to land a boat properly, and there are no trees, which the bugs loved to inhabit back on their native island. Even the shrubs the insects live on seem to occupy only a small 30-metre-long area. It's not a location you'd bet on for supporting the future of a species, even for an insect.

Ball's Pyramid. Image: Fanny Schertzer, Wikimedia Commons

It isn't even clear how the insects got to Ball's Pyramid in the first place, though bugs – and their eggs – have been known to cross the sea on floating vegetation, or as accidental hitchhikers on birds.

After some debate, conservationists decided to pull four of the bugs off the rock. Two of them died in the care of a private breeder in Sydney, but the other two became the founders of the Melbourne Zoo Lord Howe Island stick insect breeding programme. Since then, the population has laid thousands of eggs, which have been sent to a number of zoos around the world, including the very excited folks at San Diego.

But successful breeding is only one step – albeit an important one – on the road to recovery for this species. Next objective: return the insects to their home island, where they can reclaim their position in the local ecosystem. Conservationists are exploring ways to restrict access to the islands and to control dangerous invasive species such as Morning Glory vines (which destroy plants the bugs rely on) and the pest that started it all: the black rat.   

Besides making the environment safe for the insects to return, it is also important to make them welcome, which means getting the local human population on board. As of 2011, Lord Howe Island was home to 360 people, and they'll soon need to learn to live with a bunch of 12-centimetre "tree lobsters".

And for some of the rest of us, a visit to the San Diego Zoo to get to know these critically endangered arthropods might be an option. Zoo officials say the eggs should hatch in the spring of 2017, releasing tiny, bright-green baby bugs, the start of the next generation, and the key to the future of this incredibly lucky species.


Top header image: San Diego Zoo