Birds, Leps, Observations & Generalities - the images and ramblings of Mark Skevington. Sometimes.

Friday, 18 September 2020

Bumps, Balls and Blisters

 In lieu of anything more exciting, here's some galls from Croft Hill on Monday .....

This is the reddened upperside and distinctly unpleasant looking underside of a pear leaf galled by the fungi Gymnosporangium sabinae, commonly known as Pear Rust. This is one that requires two hosts to complete a cycle: a summer form that mainly affects pear, and a winter form that affects Juniper. There are four Gymnosporangium spp. that require Juniper plus secondary hosts. This one on Pear is quite common in VC55, Gymnosporangium clavariiforme (Tongues of Fire) which uses hawthorn is much less common. This is certainly due to the Juniper involved: G. clavariiforme needs Wild Juniper (Juniperus communis) which is pretty much non-existant in VC55 apart from a couple of sites where it has been planted. G. sabinae used a cultivated Junipers, such as Juniperus sabinae - clearly more of that around.

The next two galls are caused by wasps, and both are on Quercus sp. oaks:

This is a asexual generation gall of Neuroterus albipes. Quite different from the more usual 'spangle' galls caused by other Neuroterus spp. as they are a lot smoother.

And these are the asexual generation galls of Andricus lignicola, generally known as Cola Nut Galls. I'm not sure if this is because they are meant to resemble Kola Nuts, or because they taste like the 'cola' flavour from the nuts. I didn't fancy testing the latter theory, at least not without a dark rum to mix it with.

Galls are cool, uh?

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