Worcestershire Record No. 17 November 2004 p. 54

J.J.Day

I have been recording plant galls, on a casual basis, since the mid-1980s. Over the past few years I have adopted a more systematic approach, attempting to record all those I see.

In August 2004, I ran out of WBRC recording slips and resorted to entering all my records on an Excel spreadsheet. As the recording season draws to a close, it struck me on looking down the table, that there may be some useful comparative data in my records.

The following results are based on my observations August 2004 to November 2004.

There are two common gall-causing eriophyid mites. These form small reddish pustules or pimples on the upper surface of the leaf - Aceria aceriscampestris forms abundant small red pimples, Aceria macrochelus tends to occur in much smaller numbers and forms larger blunter brownish-red galls

I have 31 records from 34 sites

Oaks have a diverse associated fauna, including gall formers. Prominent amongst the latter are Cynipid Wasps. All my observations, as tabulated below, belong to this group.

I have 96 records from 55 sites

There are three British species of mites which form galls on Alder leaves.

I have 21 records from 18 sites

There is a new and excellent set of keys to galls: