These spiders fall into the category of ‘Identification by Rarity’. There are five species of Araniella in Great Britain, but three of them are rare and have a very scattered and local distribution (*). The other two are common and hard to tell apart in the field, these are A.cucurbitina and A.opisthographa. We now believe we have both species present in the garden. The only way to really tell the apart is by close examination, however there is one obvious external characteristic that can help tell them apart, if you can see it.
Araniella cucurbitina when viewed from beneath has a red patch just behind the spinnerets as shown in the photographs below. This is missing from A.opisthographa.
We were not sure if we had A.opisthographa until we filmed the interesting fight below between a Cucumber Spider and what we believe to be a male wasp, Gasteruption jaculator. It turned out to be less of a fight and more of a hopeless struggle in the end for the wasp which had become stuck in the spiders web by one of its antenna. However if you pause it around 17 seconds in you can see the spider lacks the red patch of Araniella cucurbitina.
The spiderlings are a red/brown colour but we are yet to record one in the garden.
As of April 2022 this is one of three closely related species found in the garden belonging to the same family, the Araneidae, otherwise known as the Orb Web Spiders. The other species are the familiar Garden Spider – Araneus diadematus and the fantastic looking Zygiella x-notata.