A RARE HOVERFLY thought to have disappeared from London has been rediscovered in Stoke Newington.
Pocota personata was identified by Dalston’s Russell Miller in Abney Park N16 0LH, above, the, uhm, no-longer-receptive, cemetery beloved of goths, drinkers and others street people, not to mention naturalists.
He describes the fly as “an excellent bumblebee mimic”. As his picture on this page suggests, it is difficult to distinguish from a bumblebee because of its bands of fluffy black, yellow and white hairs.
But they all have their place and have become the responsibility of rapacious humankind. People sometimes mistake some of the UK’s near-300 species of the hoverflies for bees or wasps.
The delicate creatures – elegant, even – can often be seen in gardens in spring and summer as they hover, looking to extract nectar from flowers. (Obviously the rarity of Pocota personata means the species is unlikely to be seen.)
The larvae of many hoverflies eat aphids and contribute to the pollination that is so important to carrots, onions and fruit trees.
Other flies can hover but the hoverfly, unlike them, keeps its head rigid.
The species Pocota personata could be called a Cockney: the insect was first drawn by London entomologist Moses Harris (1730-c. 1788), from a specimen taken in Stepney in the revolutionary summer of 1776. (Pleasant to think that the ructions then occurring in the British Empire did not distract the scientist from his obscure, yet in its own way also radical, work.)
The bewigged gentleman would be pleased to learn that the bumblebee-mimic is now considered “nationally scarce”, an improvement on its previous rating of “vulnerable”.
Miller comments: “The rediscovery of this remarkable species in inner London, so close to where it was first described in 1776, is a great advertisement for urban ecology.”
David Altheer 260516
* Russell Miller’s scientific paper on this curious insect
* Abney Park picture © DavidAltheer [at] gmail.com. Available for sale for reproduction.
* Insect photographs © Russell Miller, Moses Harris drawing courtesy Wikimedia
* Emboldened underscored words in most cases indicate a hyperlink, a reader service rare among websites. If a link does not work, it is probably because the site to which the URL refers has not been maintained.