The International Union for the Conservation of Nature (IUCN) publishes the Red List.   It is a list of species that are under threat in different parts of the world; it goes back to 1964 when it published the ‘list of threatened plants’. By 2012, the IUCN assessed a total of 63,837 species and reported on their status in the following terms: Extinct (EX) – No known individuals remaining. Extinct in the wild (EW) – Known only to survive in captivity, or as a naturalised population outside its historic range. Read more...

You may well have heard that bees are in trouble. Domestic honeybee hives seem to die more often than they used to, and some of our wild bees have disappeared altogether; for example, three of the UK’s twenty seven bumblebee species have gone extinct. The big, long-term driver of declines has been farming intensification; where once we had plentiful hay-meadows and chalk downland, rich with flowers, we now have flower-free monocultures of wheat or silage grass. Pesticide use is also contributing to the problem, particularly new generations of systemic, persistent insecticides called neonicotinoids that get into nectar and pollen of both flowering crops and wildflowers. Read more...

Following on from last week's post, the woodlands blog has often reported on the problems facing honey bees and bumblebees - from the vagaries of climate to the effects of insecticides, such as neonicotinoids.  Whilst it is easy to identify a honey bee and spot a bumblebee, it is somewhat more difficult to say what type of bumblebee might be foraging in your garden or woodland. There is a lot of information about bumblebees at the bumblebee conservation trust website.  A particularly useful link is "Top tips for bee ID"; tail colour is an important or helpful feature.  Read more...

DDT was used an insecticide at the onset of WW2, with great success in terms of controlling malaria and typhus among civilians and troops. After the war, it was available as an agricultural insecticide.  However, within a few years, there were warning signs that not all was well and in 1946, the Soil Association journal read as follows "By the wholesale use of powerful insecticides of which far too little is yet known, we may well be upsetting the whole balance of Nature. We are like schoolboys rat-hunting in a munition dump with a flame-thrower." Some years later (in 1962),  Rachel Carson published ‘Silent Spring’ – which seriously questioned the use of organochlorines, such as DDT and warned of the dangers of the indiscriminate use of insecticides.  The use of these chemicals continued Read more...

The Bumblebee Conservation Trust, based at Stirling University, needs your help in recording sightings of bumblebees. They would like you to record what species you see, where and how many, and take pictures of any unusual specimens. Go to http://www.bumblebeeconservationtrust.co.uk/surveys.htm to find out how to take part. 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...

We can communicate in many ways, other animals may  message each by vocalising or gesturing.  Some release air-borne chemicals (pheromones) to attract a mate.  Plants also communicate by chemical signals that they release into the environment. The most obvious example is the release of scents to attract pollinators.   These floral scents are usually oils, made from volatile organic compounds (VOCs).  VOCs are carbon based compounds, such as the terpenes. They usually have a strong and pleasant odour.  They form partt of the scent of many plants, for example, honeysuckle, roses, jasmine, lilac, and mock orange.  Different plants produce different scents.  These different chemical signatures help pollinators identify particular species, and locate the nectar on offer. The VOCs produced by ripe fruit help attract animals that assist in seed dispersal. [caption id="attachment_43370" align="aligncenter" width="675"] Buff tailed bumblebee visiting a foxglove[/caption] VOCs are also produced by leaves when plants are under attack.  These may deter the attacking organism directly, e.g. caterpillars, or they may attract an organism that predates upon the herbivore. When pollen beetles feed on oil seed rape, the plants release VOCs which attract the attention of insects (a type of wasp). The wasps lay their eggs in the larvae of the pollen beetles. The pollen beetle larvae are then ‘eaten alive’, by the developing wasp larvae.  Sometimes, VOCs are produced by stressed or attacked plants,  these VOCs ‘warn’ nearby plants of the same species. These plants can then activate their defences before they are attacked. This helps ensure the survival of some of the population. Recently, it has been suggested that mycorrhizal systems act as a physical and chemical ‘means of communication’ between the trees in a woodland, in what has been termed the ‘wood wide web’. The term was coined by Dr. Suzanne Simard, a forest ecologist at the University of British Columbia to describe the complex relationships between fungi and plants in woodland ecosystems.  Interestingly, VOCs can influence air quality and atmospheric processes.  In a woodland,  the scent of pine or other conifers may permeate the air.  Pines release volatile compounds, such as alpha-pinene.  Recent research has established that these volatile compounds / vapours are not only responsible for the characteristic scent, but also contribute to the formation of aerosols in the atmosphere* both in and around such woodlands and forests.  In the presence of sunlight, VOCs can interact with the gas nitric oxide to form ground level ozone, which contributes to smog formation. Forests can be a significant source of VOC emissions. The production of VOCs is affected by environmental  conditions.  VOCs release generally goes up with an increase in temperature, as the plants metabolism increase.  An increase in temperature also helps in the evaporation / volatilisation of plant oils and scents. Water availability and light intensity also affect VOC release.  * An aerosol is a ‘mixture’ of very small particles (solid or liquid) in air; other examples of aerosols include mist, cigarette smoke, or car exhaust fumes

There are some 270 species of bee to be found in the UK.  Most of these bees are solitary bees. Solitary bees do not form colonies like the honey bee, with a queen and workers. Twenty four are types of bumblebee,  although two of these bumblebees may be extinct in the UK.  Included in the bumblebee category are the carder bees. Their name relates to their ability to ‘knit’ together plant materials / fibres to form a nest*.  The six species of carder bees in the UK are listed below : The common carder bee The brown banded carder bee The moss carder bee The red shanked carder bee The ruderal carder bee The shrill carder bee The common carder bee (Bombus pascuorum) is quite widespread and is found in gardens, the edges of woodland, and farmland throughout the country.  It is a social insect, forming colonies with worker bees.  Their yearly cycle is not dissimilar to that of bumblebees.  In spring, queen carder bees emerge from hibernation and establish new colonies. These develop throughout the spring and summer, adding workers.  By late summer, new queens and males are formed, and in autumn the old queen and workers die.  The new queens overwinter and emerge in the following spring. [caption id="attachment_43305" align="aligncenter" width="675"] Common carder bee[/caption] Carder bees tend to build their nests on or near the soil surface, using moss, dried grass or similar plant material.  The shrill carder bee favours flower-rich grassland areas to build its nest.  As so many of these diverse grasslands have disappeared over the last century, it explains the rarity of this particular bee.   Carder worker bees are a ginger / warm brown colour. Carder bees are noted for their ‘long tongues’, i.e. their mouthparts have a long proboscis [feeding tube].  This allows them to reach the nectar inside flowers with a long, tubular shape (such as foxgloves, honeysuckle and clover).  It also means that they are not in direct competition with ‘shorter tongued’ bees, who can only access open flowers.    Whilst visiting flowers, they act as pollinators of both wild flowers and farmland crops. As pollinators, they help promote the transfer of pollen from plant to plant, promoting outbreeding which in turn helps maintain variation with a species. The bees actively forage from spring into autumn and can thrive in our extensively modified landscape, so they are key pollinators in both rural and urban areas. * Originally, the term a carder referred to person who combs out and cleans fibres of wool / cotton before spinning.