Postcard: London
By Eben Harrell
As collections manager at London's Natural History Museum, Max Barclay has traveled the world in search of rare and previously undiscovered insects. So when his 5-year-old son took a break from a picnic lunch last March in the museum's garden and returned with an insect in his hand, Barclay could not have guessed that his question--"Daddy, what's this?"--would lead to a global detective hunt that has so far stumped Barclay and the world's other entomologists.
Despite working with an insect collection of more than 28 million specimens, Barclay and his colleagues have been unable to identify the almond-shaped critter, about the size of a grain of rice, which has in the past year made itself at home in the sycamore trees on the 19th century museum's grounds in central London. "My field work has taken me all over the world--to Thailand, Bolivia, Peru. So I was surprised to be confronted by an unidentifiable species while having a sandwich in the museum's garden," Barclay says.
Within three months of the discovery, the insect had become the most common species in the garden and was spotted in other central London parks, sending Barclay on a worldwide hunt to identify it. Correspondence with colleagues around Europe led Barclay to discover that the insect, which resembles the common North American box elder bug, is actually most closely related to Arocatus roeselii, a relatively rare species of seed eaters usually found in central Europe. But those bugs are associated with alder trees rather than sycamores. An insect specimen found in Nice, France, which is now in the collection at the National Museum in Prague, turned out to be the same as the mysterious London bug. But that specimen had been misidentified as Arocatus roeselii. "There are two possible explanations," says Barclay. "One is that the bug is roeselii, and by switching to feed on the [sycamores], it has suddenly become more abundant, successful and invasive. The other is that the insect in our grounds may not be roeselii at all."
In recent years, several foreign insects, spiders and beetles have been discovered in Britain, a trend many attribute to the ability of such species to survive winters warmed by climate change. In 2005 Edinburgh Zoo issued a public notice after several panicked Scots reported seeing a spider called a false widow, which has a disconcerting behavior of rushing toward people who approach it. The spider turned out to be quite common--in the Canary Islands.
Barclay is not convinced that climate change is responsible for Britain's new inhabitants. European integration may be the cause. "It's very difficult to judge," Barclay says, "because the period of time we have seen global warming potentially influencing the insect fauna is almost exactly the same period of time since the [European Union] opened up its trade barriers between member states. So in the past decade and a half, we've been importing a lot more from Italy and Spain and Southern France, and we've had this climatic change--so we have two potential causes." Whatever the reason for the appearance of the new bug in London, Barclay says its spread is harmless. But he concedes, "It does show what's possible [if more damaging species invade]."
The struggle to identify the museum mite displays not only the mystery of nature but also the fickleness that surrounds the science of taxonomy. Figuring out which insects are which can be fiendishly difficult; some scientists estimate that we have managed to identify only 10% of the insect world so far. The rest, like Barclay's almond-shaped mystery bug, are perfectly happy to crawl along without any christening or approval from their gargantuan neighbors. But that won't stop scientists like Barclay from trying to give his new chums a proper name--that is to say, a Latin one. For Barclay, the question asked by his son last March amounts to a calling he still feels compelled to answer.
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