Finding the Caribbean ant queen
PUBLISHED: 14:47 25 November 2014 | UPDATED: 15:01 25 November 2014
After a devastating accident at the UK's largest leafcutter ant colony at Butterfly World near St Albans, a team was sent to the rainforests of Trinidad to capture a new queen and 10,000 angry followers, Carrie Bone reports
Last year, Butterfly World Project in Chiswell Green, near St Albans, was home to the largest colony of leaf cutter ants in the UK, a popular exhibition that educated visitors on the importance of these tropical insects.
But in December, ants in the one million strong colony chewed through an electrical cable in their glass cabinet, electrocuting and killing the queen. Without a leader, the surviving ants lost purpose, fighting one another and starving. All died shortly after.
With a plan to create a new colony, leading staff at Butterfly World commissioned Andrew Stephenson (left) of Zoologica Exhibito, who brought the original ants to the conservation and education centre, to return to the rainforests of Trinidad in search of a new queen.
With more than 20 years’ experience in the field, Stephenson employs a team of 70 people and supplies animals for educational purposes, as well as building and designing zoos all over the world in which to house them. Most leafcutter ant colonies in Europe have been supplied by Stephenson, who splits his time between the ants’ Caribbean haunt and his home in Scotland.
Well known to the farmers in Trinidad as the ‘bachac man’ (ant man), Stephenson works with the farming communities, paying them not to kill the ants so he can collect them before the planting season when they would be exterminated as pests. ‘The farmers are happy and appreciative,’ Stephenson says of the arrangement.
‘I used to go hunting day after day looking for ants,’ he adds. ‘Now I get in touch with guys who find them for me. If it’s a big colony I’ll go and dig it up myself, because if you don’t find the queen then you don’t have a colony.’
Leafcutter ants are native to Central and South America and grow to 16mm in length (different sized ants do different jobs in the society). Workers are responsible for cleaning the nest, building tunnels, foraging and cutting leaves. Soldiers are the security guards, patrolling the immediate area around the working ants to protect them from parasitic flies and wasps.
A wild colony, which on average has five million members and is the size of a small car, can do significant damage to vegetation in a short space of time. The insects strip leaves from trees and crops and anything that puts shade over their nest. A colony can defoliate a tree in a day.
The leaves themselves are not what the ants eat, however. Like the farmers they live alongside, leafcutter ants grow crops deep within the nest. Leaves are taken to this ‘garden’ area where they produce a fungus which provides food for the colony.
Collecting this fungus is as important as capturing the queen to Stephenson. While only the queen reproduces, without the fungus the colony would fail.
‘The fungus garden is where you’ll find the queen,’ he says. ‘If the queen isn’t there the search continues. It took a day and a half to find the queen for Butterfly World. The queen is huge (the size of a mouse), and once you’ve found her the other ants cocoon around her to protect her.’
A high pain threshold is needed for the operation, as soldier ants will launch an attack as soon as the nest is disturbed. ‘If you can see soldiers, it’s a big nest and as soon as you disturb it they’ll come out and disturb you,’ Stephenson says.
In the heat and humidity of the Caribbean, protective clothing is something Stephenson and his team go without. ‘The biggest problem is the big soldiers ants come out and maul us. They get in our clothes and sink their teeth in.’ When bitten, he adds, the only choice is to ‘man up and take the pain.’
Once the queen, fungus garden and around 10,000 of the colony were collected, the hardest and most expensive parts of the journey began. ‘The main cost of the journey is the freight trip home,’ Stephenson explains. ‘Transporting ants gets more expensive the bigger the colony is.’
The ants were put into boxes to be flown to England, but in order for them to survive the journey they needed food. ‘The fungus needs the ants, and the ants need the fungus, which is extremely delicate. If it’s too warm or there aren’t enough air holes in the boxes then there will be ants and no fungus which means no food for them.’
The trip was a success however, and a new colony of leafcutters is establishing itself at Butterfly World, building a new home for their queen. Ropes have been installed for the insects to follow and they will travel up to 50 metres in search for food. Visitors can watch the colony as it operates, sending out leaf gatherers, harvesting the foliage and patrolling the territory.
The centre anticipates the colony will be back to its previous size within 18 months, as the queen can lay up to 30,000 eggs a day.