We asked Peter Brash, Animal Ecologist for the National Trust, to tell us about his favourite insects as part of National Insect Week:
“I always find it difficult to choose favourites. When asked to write this blog for National Insect Week I knew I was going to have a difficult choice.
“As an entomologist and a naturalist I’m a bit of an all-rounder, a jack of all trades. After birds lit my fire for natural history at the age of ten, the conflagration has spread to plants, fungi and insects. Unlike some sensible folk who focus on one group I’ve attempted to master flies, bugs, bees and beetles. So choosing a single group is difficult.
“I do have a great fondness for bees but I’m an even greater fan of the unrelated species that masquerade as bees or wasps. These Batesian mimics adopt the colouring of stinging bees and wasps to avoid predation by other species.
“One of the most common is the wasp beetle Clytus arietis, a type of longhorn beetle that develops in timber and branches. While the yellow on black warning disguise is not totally convincing, the fact that the beetle will run about and engage in furious antennae cleaning does give another strand to the deception. This is one of the most amazing things about the mimics; natural selection appears to have worked not only on colouration but also behaviour.
“The hoverflies as a group have taken mimicry to extreme levels. The Chrysotoxum family have the black banded yellow body of a wasp and often zigzag in flight just like the stinging insects that they imitate. The antennae are longer than other hoverflies, possibly in part to make them even more credible as a wasp.
“The hornet hoverfly Volucella zonaria is one of our largest flies and its yellow, black and chestnut livery enables it to live off the fearsome reputation of its namesake. Formerly a great rarity, this species is spreading across the country, but is still most likely to be seen in the south-east of England.
“Many of the hoverflies are bumblebee mimics with varying levels of proficiency. Volucella bombylans seems to be so good at passing itself off that it is allowed entry into bumblebee nests where its larvae consume not only debris but sometimes also the larvae of the bees themselves.
“My vote for the ultimate in bumblebee ‘doppelgangery’ though goes to the rare and elusive Pocota personata. This large hoverfly develops in the rot holes of ancient trees, mainly in the south of England. For years this has been on the list of my ‘most-wanted’ and I’ve dreamt of finding this crème de la crème of bee mimics. I’ve lost count of the times when my heart has leapt as a bumblebee has approached a tree in a woodland, my hopes only to be dashed as I realise that it’s the ‘real thing’.
“Pocota (fleecy in Greek) personata (masked in Latin) has been my undoubted wildlife highlight of 2014. While having lunch next to a rotting beech hulk at Shugbourough near Stafford my eye was drawn to a rotund furry insect decked out in black, white and yellow. Lifting my binoculars I realised this was the fabled beast, the small head and short antennae are distinctive and the patterning has a crispness that the other mimics can’t match. This was a real arms aloft moment, a decade ambition realised and proof of the magic of insects.”