Cherry Galls

[Deer Stalker]

Been seeing loads of Cherry galls made by the gall wasp Cynips quercusfolii on fallen oak leaves this autumn where I am (sorry, no pics). Anyone else having an abundance of these this year?

[nightshade]

A tree in the carpark had as many cherry-galled leaves as acorns on the floor

[Paul mabbott]

Originally Posted by nightshade

A tree in the carpark had as many cherry-galled leaves as acorns on the floor

Hardly any oak galls of any kind in my necks of the woods this year.

[aeshna5]

Like Paul, I've seen few oak galls, especially the various spangle galls, though Knopper Galls have still been fairly common around London.

[Rainbowmum]

Can you explain a bit more about Galls please
Louise x

[aeshna5]

Galls are growths usually on plants, but sometimes fungi, caused by other organisms. Some of these galls are very noticeable such as some that occur on oaks or Robin's Pin Cushion on roses. The gall causer effects the plants normal cell differention, so resulting in a distinct growth which is fairly constant for any given gall type.

A wide range of organisms can cause galls-various insects such as tiny wasps, sawflies + true flies, mites ( such as little red bumps you might see on Sycamore leaves), bacteria, viruses + fungi.

There's even a British Plant Gall Society for devotees of these organisms. Field Studies Council have produced a good laminated fold-up guide to some of the commoner, more noticeable galls for a few pounds. If you look in general insect fieldguide you will see a few galls in there, such as some of the tiny wasps that cause the various galls on oaks.

[Deer Stalker]

Sorry Louise.
Galls on plants (strange, abnormal looking growths) can be caused by many organisms like insects, fungi, viruses. The shape & size of the gall is determined by the thing that cuases it.
The Cherry galls I was on about are red/green marble sized balls on the underside of oak leaves & are the trees reaction to the larvea of the gall wasp (Cynips quercufolii) hatching inside the leaf. The larvea will feed up on the nutricious growth that is produced by the oak & the female wasps (tiny little things) will emerge from december to february & lay thier eggs (they are parthenogenetic, which means they don't have to mate to produce eggs) in the oak buds.
These, when they hatch, cause small purple galls in place of the buds & produce the sexual generation which mate & lay there eggs on the leaves to produce the next lot of Cherry galls & parthenogentic females in summer/autumn.
Cherry, Spangle, Knopper, Artichoke are some common ones of about 300 species of gall wasp that rely on oak, each having their own type of galls.

[Deer Stalker]

Ahhh. Beat me to it Aesh.

[aeshna5]

Having just picked up my latest copy of BBC Wildlife mag, there's a small feature on galls near the front, depicting 9 types of gall, for anyone who's interested!

[Alan]

Noticed loads of these at Clumber Park, Worksop at the weekend.

The book 'Small Woodland Creatures' (ISBN 0-19-850797-6), as well as insects and other inverts, has a useful section on galls and their causes.

Alan