Powerless against using the most obvious weapon against the invasive insect, Russian scientists turned to exotic ones. They released thousands of small wasps native to China hoping they would kill the box tree moth caterpillars, but the moth population only continued to grow. They experimented with another type of wasp, but it preyed only on other insects, avoiding the caterpillars, which absorb toxins from the box tree leaves. According to Shiryaeva, they found a parasitic fungus that killed 90 percent of box tree moth caterpillars in the lab, but Sochi’s torrential rains washed away the fungus solution once it was applied in the forests, preventing it from taking effect.
A box tree moth caterpillar with nothing left to eat, near Guamka, Russia. Visual by Maria Antonova
As a result, in just two years, 99.9 percent of the box tree forests in Abkhazia, Georgia’s breakaway republic bordering Sochi, were eaten by the moth, says Roman Dbar, who heads the Institute of Ecology of the Academy of Sciences there in the city of Sukhumi, and who has become a point person on the forest catastrophe. Originally from Asia, the box tree moth has successfully conquered the entire European continent, with plant lovers from the Spanish Pyrenees to Western England saying goodbye to box hedges, a quintessential element of any respectable garden. The situation in the Caucasus, however, is more tragic: Not only has the moth hit endemic Colchic box forests in tough-to-reach mountain areas, its spread has been more rapid and destructive here.
In Sochi’s warmth and humidity, the moth can reproduce up to four times a year, with each female laying over 200 tiny translucent eggs. The offspring of just one of the insects can completely defoliate a fully-grown box tree bush, lab results have shown. Without leaves, the tree may for survive for at most two years, Dbar says, but its failure to photosynthesize eventually dehydrates it completely. Death is even quicker for trees where the caterpillars have removed the bark as well.
In the Colchic boxwood forests, people reported clouds of white moths so thick it looked like it was snowing in the middle of the summer.
In the Colchic boxwood forests, people reported clouds of white moths so thick it looked like it was snowing in the middle of the summer. In parks, tourists were provided with sticks for moving aside caterpillar webs as they walked along the trails, but the presence of the insects is devastating. In one protected area in Russia’s Adygea region, I stood on a hill that used to be a boxwood forest, whose dense canopy of leaves blocked out the sunlight and kept the area shrouded in mist. Today the forest is little more than a barren wasteland covered in dry brushwood.
As the plant disappears, other species of worms, scorpions, and lichens that relied for millions of years on the humidity and shade it provided will likely also disappear, scientists say, and the full scope of the consequences is still unknown.
The Russian government recognizes the importation of contaminated plants as the reason why a rare species has nearly gone extinct in Russia. When at a recent event I asked the Russian environment minister, Sergei Donskoi, who is to blame for the plant’s demise, he declared that he is “not an investigator.” Then he added that the pest was mistakenly brought into the country and spread.
But scientists argue that the government should have put up a fight instead of sitting back as the disaster hit. The ban on insecticides should have been tweaked to allow Sochi National Park to carry out its obligation to protect rare species, Shiryaeva says. “These laws were written ages ago, but our world is changing, and the laws should reflect real life.” Globalization creates more risks, as Russians bring exotic plants back from their travels and plant them in their gardens, where once they were perfectly content with simple apple trees and currant bushes.
For now, Russia has few, if any, protocols at the border for testing plants and other goods for pests and pathogens, Shiryaeva says. “They have to have specialists sitting there who would know the invaders in the face — similar to how they look for terrorists.”
Alexey Bibin, a senior researcher at the Caucasus Nature Reserve, is working to create a sanctuary for wild-growing Colchic box trees. Here, he is surrounded by specimens destroyed by the caterpillars. Visual by Maria Antonova
Even in the face of almost complete devastation, there is a chance to save the Colchic boxwood from extinction. One Russian scientist, Alexey Bibin, a senior researcher at the Caucasus Nature Reserve, selected a small plot on a piece of flat ground for an experimental project to create a sanctuary for wild-growing Colchic box trees. Sporadic surviving trees — all around 100-years-old and just over the average human height — are sprayed regularly with a mild biological insecticide, in a rare experimental easing of the Russian ban. Bibin and colleagues have also planted additional saplings on the forest plot, and they visit several times a month to check on them.
“This is the only reserve of the genetically pure Colchic population in Russia from which we could take seeds and grafts, to restore it in its habitat,” Bibin says, adding that the project was a last resort, after years of government meetings, roundtables, and conferences about the box tree crisis. “It became clear that Russia is not planning to do anything, despite it being a federally-protected plant,” he says. “If I go and cut down a box tree shrub, I’ll be fined 25,000 rubles (about $420), but when the entire species is dying at the fault of the government — they have disregarded this since the government cannot fine itself.”
It could be decades or even centuries before the box tree, an extremely slow-growing plant, has any chance to be restored in the wild, but scientists like Bibin say seed banks and surviving fragments of the forests are at this point the only way to ensure the plant’s genes don’t disappear from nature completely.
To that end, Dbar’s institute in Abkhazia has recently outfitted a new lab to deep-freeze box tree seeds over the next decade while waiting for the invasion to pass, or possibly for natural predators to emerge that would keep the caterpillars in check. With Dbar’s help, a grove of tall, mature box trees was saved in the mountains, where a local café took it upon itself to consistently treat the trees with insecticide.
Today tourists flock to the grove, savoring its cool emerald shade and the aromatic scent of its leaves. It is probably the last remaining piece of truly ancient boxwood forest in the Caucasus, Dbar says, and the seeds could be harvested there, though lack of synergy between governments in the region means scientists will probably not be able to exchange seeds and saplings for greater effect.
Meanwhile, the moth’s invasion, rapid breeding, and complete destruction of a singular plant species, should be studied as a lesson for the future, he adds.
“The world is rational, and the box tree doesn’t seem like it’s important for the survival of humans,” he says, explaining why authorities have not seriously considered tackling the problem. But its evisceration could be viewed as a model for other, more serious threats, he says, calling this type of catastrophe unprecedented in modern history.
“Humans themselves are rather vulnerable. They can attract a newly-formed or relict type of parasite, virus, or bacterium,” he says. “It’s a model of a kind of Plague of Egypt — which can happen anywhere, and would be hard to predict.”