When I got my new guide book*, I very naively assumed it would help me identify all the spiders I saw. I should have known from tackling all the other types of creatures I’ve been trying to put names to that nothing is ever that easy.

These three spiders are a case in point. They all belong to the Philodromidae, the running crab spiders, of which, in Britain, there are 17 eight-eyed species in four genera.

Though they share a similar crab-like body structure, the three shown here all look quite different to my eye, and I thought I would be able to identify them but no! Highlighted in red in my book are those words I never like to read: ‘Microscopic examination of the genitalia is necessary to confirm identification of all species in these genera.’

* Lawrence Bee, Geoff Oxford and Helen Smith, Britain’s Spiders: a field guide, 2nd ed., Princeton University Press, Princeton, 2020.