As reported in the woodlands blog last year, the red squirrel population in the UK is under threat. One of the threats is the parapox virus. This virus seemingly does little harm to grey squirrels (who act as a reservoir of infection); but red squirrels, once infected, develop skin ulcers, Read more...

There are many hundreds of species of Rhododendron, many of which produce impressive floral displays. They belong to the plant family known as the Ericaceae, which includes the azaleas, heathers, cranberries, and blueberries. Plants in this family can form mycorrhizae. These are symbiotic root associations with fungi; these help in the uptake of minerals, which probably explains why such plants can compete successfully in poor soils. Read more...

The oak has long been regarded as the King of the Forest and emblematic of the UK.  It is the largest of our native, broad-leaved trees.  There are two native species of oak; the sessile oak (Quercus petraea) and the pedunculate oak (Quercus robur).  Oaks belong to the beech family, Fagaceae. Read more...

Britain has two types of squirrel, but only one of them – the red squirrel – is actually native to the country. The grey squirrel was introduced into the UK about 130 years ago. There are now some 2.5 million grey squirrels in the UK, compared to 160,000 native red squirrels. The majority of the red squirrels are now found in Scotland, Wales and North East England, with smaller populations in places like the Read more...

We reported in this blog back in May that Horse Chestnuts were under threat from the leaf miner moth (Cameraria ohridella) and the fungus (Guignardia aesculi). Not to mention the effects of drought! Now there is another, greater threat to these stately trees – namely Bleeding Canker. The first symptom is often an area of bark where a yellow / brown / red liquid seeps out. In the spring, this coloured fluid is usually transparent but in warmer weather Read more...

Bumblebees are regarded as nice, gentle creatures; even their buzzing has a placid, reassuring sound. They rarely sting and are important pollinators in orchards, on farms and in our gardens. Sadly, however, they are under threat. Many species of bumblebee are on the decline and have been, according to some authors, since the late 1950’s. Their decline is often attributed to the introduction of intensive agricultural techniques. For example, Read more...

There are presently some 46 species of ladybirds found in the UK. For an excellent sheet on identifying the most common species, click here. However, some of these species may now be under threat due to the arrival of the Harlequin Ladybird. This was introduced to the United States in 1988 and now is the most widespread ladybird there. A single female can lay a thousand eggs. To learn how to identify this new arrival click Read more...

The horse chestnut or conker tree (Aesculus hippocastanum) was probably introduced into this country in the late 16th century. It has been extensively used in artificial plantings along roadsides - in creating avenues. In Spring, the statuesque trees are covered with white flowers, sometimes referred to as candles (see picture). Pink and red flowered forms are hybrid types. The horse chestnut is recognisable by its distinctive shape; they have arching branches, which turn up at their ends. They also have distinctive palmate (hand shaped) leaves with prominent veins - see https://www.woodlands.co.uk/blog/tree-identification/horse-chestnut/. Another feature that is characteristic to the tree is its seed – the conker, which is formed in the autumn within the prickly fruit. At one time, these were used as an animal feed. The wood of the tree is of little economic value. Horse chestnuts were often planted in by local authorities, in part because of their impressive appearance but also because of their low incidence of fungal disease and pests. However, they are subject to attack by one particular fungus and also a moth. The fungus that attacks the tree is called Guignardia aesculi or the leaf blotch fungus. Reddish brown patches appear on the leaves (from July onwards), particularly at the tips and edges of the leaflets. A closer look will reveal small black pimples, which are the fruiting bodies of the fungus. Infection may result in some of the leaves falling early, but it does not usually result in significant damage to the tree. However, infection of the horse chestnut with the larvae / caterpillars of a small moth (Cameraria ohridella) has a much greater impact. These caterpillars feed on the tissue between the upper and lower surfaces of the leaf, producing ‘mines’. These are tunnels through the leaf where the tissue has been eaten. If the leaf is held up to the light, such tunnels (if fresh) may appear translucent. The loss of the green photosynthetic tissue eventually results in the death of the leaf and early leaf fall. The caterpillars pass through several stages (instars) when the skin is shed and growth occurs. After about 4 weeks (in the summer), they pupate and emerge some 2 weeks later (again, in the summer months) as the adult moth. And the cycle of egg laying and hatching to caterpillar etc. begins again. Many types of tree are infected by leaf miners, but these do not (usually) have dramatic effects. However, the horse chestnut can suffer very severe infestations with these moth caterpillars so that all the leaves fall prematurely; the tree is basically defoliated.  Conkers may be reduced in size. The moth seems to flourish in very dry conditions. Outbreaks have occurred in the UK in recent years. The first was noted in Wimbledon in 2002, but it has since been seen in many places from North Norfolk to Newport in Wales. The moth is an invasive species, and is thought to have originated in the Balkans ('home' of the horse chestnut).   The spread of this pest is being monitored; if you can help or have any information then the following links may be useful: http://www.forestry.gov.uk/pdf/hcml_help_monitor_04.pdf http://www.forestry.gov.uk/fr/INFD-68JJRC/ For further information, see: http://www.forestry.gov.uk/website/pdf.nsf/pdf/horsechestnut.pdf http://www.defra.gov.uk/news/latest/2002/leafminer.htm For an image of the moth, see : http://www.forestry.gov.uk/fr/INFD-68JJRC/ http://www.defra.gov.uk/news/latest/2002/leafminer.htm