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BRLSI and Bath Natural History Society, with help from the local Biological Record Centres at Bristol (BRERC) and Devizes (WSBRC), are accumulating an illustrated guide to local wildlife. Bath Wildlife group was formed to provide assistance in the form of workshops, for those interested in studying or recording local plants and animals. Facilities exist for you to record your observations and once they are confirmed they are made available to the general public. More info.
Meetings are at 7:30 pm unless indicated otherwise.
Programme for 2020
Saturday 18 January (2:15 pm): Workshop - Bog Life
Other workshops were planned for 2020 but the Coronavirus outbreak put paid to that. A workshop on plant galls on trees and shrubs was planned for the Summer, so by way of compensation I have posted a few sightings on the website. Illustrations of a variety of galls are available on the website and links are provided below.
Galls caused by Eriophyd mites
These mites are microscopic but they can be detected by the growths that they induce in the plants they inhabit. The simplest type of gall is an erineum, which is a hair-like growth, usually on the underside of leaves. Other mites produce a pouch-gall on the leaves, which usually comprises a swelling on the upper side, with a small hairy opening on the underside of the leaf.
Galls of Eriophyes inangulis and E. laevis on Alder leaves. The former produces the larger blisters near the midrib. The latter, the small red growths elsewhere.
Galls of Aceria campestricola on leaves of Small-leaved Elm.
Galls of Aceria fraxinivora on Ash keys.
Galls of Cecidophyopsis malpighianus on flower-buds of Bay Laurel.
Gall of Stenacis triradiata on Goat Willow catkin.
Nail galls of Eriophyes tiliae on Lime leaves.
Erineum caused by Aceria ilicis on leaves of Holm Oak.
Erineum caused by Acalitus brevitarsus on leaves of Italian Alder.
Erineum of Aceria fagineus on Beech.
Galls caused by midges
These can exhibit a number of forms, especially on herbacous plants, but on trees and shruibs they are usually 'big-buds' or pouch-galls of various kinds.
Artichoke gall of Taxomyia taxi on Yew buds.
Lighthouse galls of Hartigiola annulipes on Beech leaves.
Galls of Didymomyia tiliacea on leaves of Common Lime.
Galls of Iteomyia capreae on Goat Willow leaves.
Rosette-gall of Rabdophaga cinerearum on Goat Willow leaves.
Galls caused by wasps
Galls caused by wasps are mostly found on trees and shrubs. Oaks and Rose bushes are favourite host plants, but Saw-flies in the genus Pontania produce galls on the leaves of Willows.
Ram's-horn gall of Andricus aries on Oak. New to the area in 2019.
Galls of Andricus grossulariae on acorns.
Knopper Gall of Andricus quercus-calicis on acorns.
Robin's-pincushion gall on Dog Rose.
Galls caused by bugs
Leaf-roll gall of Trioza alacris (a Psyllid bug) on Bay Laurel.
Gall caused by an aphid, probably Pemphigus populinigrae, on Poplar leaves.
Gall of an aphid (Pemphigus spirothecae), on Poplar leaf-stalks.
Red Valerian galled by Trioza centranthi (a Psyllid bug).
Galls caused by fungi
Most galls caused by fungi are in the genus Taphrina which, as well as those illustrated, forms the familiar 'witches brooms' on Birch trees.
Galls of Taphrina populina on Canadian Black Poplar.
Peach Leaf-curl caused by Taphrina deformans. This fungus can also do damage to Almond trees.