Electric bees ? Both bumblebees and flowers carry an electric charge.  Flowers have a weak negative charge, whilst the bees have a positive charge.  The attraction between these two opposing electric fields may help the bees sense flowers.  The electric charge of a bee may even stimulate a flower to release a burst of scent, aka volatile organic compounds.  This was true for petunias, but not snapdragons.  When a bee has visited a flower, the negative charge is briefly lost - maybe a signal to tell other bbees not to visit? Other work by Bristol University has indicated that synthetic fertilisers and pesticide can interfere with a flower’s electric charge for some time after spraying, and that this can modify the foraging of bumblebees. "Black bees" The black bee, Apis mellifera mellifera, faces a number of threats like the domestic honey bee.  It is also known as the European Dark Bee or the Black German Bee. It has been present since the retreat of the last Ice Age, but its distribution has become restricted as a result of habitat loss, parasitism by Varroa mites and viruses. The black bee can be distinguished from other honey bees by its stocky body and sparse abdominal hair (which is brown), and overall dark coloration - so they appear black or dark brown. Recent research (using DNA analysis) has shown that black honeybees can be found in many locations in Ireland and are not extinct, as previously suggested  Black bees are noted for their longevity and hardiness (ability to cope with winter temperatures); it is possible that if winters become shorter / milder that this change may not favour black bees. Weird weeds? It seems that our gardens may be home to ‘new’ or unusual species of plants.   The Royal Horticultural Society would like gardeners to report on interesting ‘weeds’ that might find as they could be rare plants or plants growing in unusual places / areas.  You are asked to take photographs of anything that you find interesting, and upload the images to iNaturalist. Reporting on unusual plants is not the only thing that the RHS is interested in. There are other garden projects that one can contribute to, for example, reporting sightings of garden pests such as the berberis sawfly, cellar slug, hemerocallis gall midge, lily beetle, rosemary beetle and spittlebug. Mycorrhizal networks. A common mycorrhizal network (CMN) is when fungal hyphae connect the roots of many plants (either of the same or different species) below ground.  They have attracted considerable attention in recent times (woodland wide webs), with claims, for example, that resources are transferred through CMNs to increase seedling performance and mature trees send resources / defence signals to offspring etc.  However, a recent report in Nature has suggested that there is a ‘bias’ towards citing the positive effects of CMNs and that, to date, knowledge of common mycorrhizal networks is limited.    

Several thousand years ago, Scotland was extensively forested.  As the Ice Age came to an end, so the glaciers retreated and Scots Pine, birch, rowan, aspen and juniper populated the land, forming the Caledonian* Forest.  Pollen records indicate that Scots Pine was present in southern England some 9000 years ago, it then moved into Scotland.  Scots Pine is one of the UK’s three native conifers; the other two being Yew and Juniper. As the climate warmed, Scots Pine was lost from most of England.  The pine woodland that formed in Scotland was the westernmost part of the boreal forest that extended across most of Northern Europe.  At its peak, (about seven thousand years ago), the forest covered some 1.5 million hectares in Scotland.  It was a ‘home’ to beavers, wild boar, brown bears, elk and wolves.  These have since been ‘lost’, though in recent times, the European Beaver has been re-introduced. However, with the arrival and establishment of neolithic farmers, areas of heath and woodland were burned to encourage fresh growth of heather for their cattle and goats. Some time later (about 3000 years ago), there was period of cold and wet weather, peat bogs spread and the tree line was lowered. In places, broad leaved trees replaced Scots pine.  Throughout historical times, the felling of trees for timber and fuel continued, as did the grazing of livestock.  Later came extensive sheep farming and this was followed in Victorian times by deer and grouse shooting.  All of these limited woodland regeneration.  So what was once an extensive forest was reduced to a fraction of its former size. Remnants of this once great forest can still be found and even today these woodlands offer a rich habitat that supports a diverse flora and fauna, where pine marten, capercaillie, red squirrel, Scottish crossbill and wildcat can be found.  Glenmore is a National Nature Reserve with many mature Scots Pine, Glen Tanar is another area of Caledonian* pine forest, set within the Cairngorms National Park.  The woodland floor provides a habitat for many plant species typical of the Caledonian Forest - twinflower, creeping lady's-tresses.    Rare and unusual insects are also to be found such as the bumblebee robber fly. According to a recent study by “Trees for life” many of the the remnants of the ancient pine forest are on a ‘knife edge’. Large numbers of deer have and are damaging the woodlands.  The deer eat pine saplings and damage bark. This can result in birch replacing pine. Whilst there have been efforts to exclude deer in some areas by putting fencing in place, the fenced areas were often not big enough or over time the deer were able to breach the fencing and continue to forage.  Pine trees need time to establish themselves free from the impact of grazing. Some areas of pinewood suffered from the planting (in the 1950s) on non-native conifers, such as Sitka Spruce.  As these grow they can crowd out Scots Pine.  Many others areas are small and ‘isolated’. This leads to a reduction in biodiversity, so it is more difficult for natural regeneration to occur.  It also means that resilience is lost in the face of threats like climate change.   * the roman name for the area now Scotland was Caledonia.   Scots Pine is sometimes described as an ‘honorary hardwood', as it grows slower than certain conifers and produces better quality timber. The loss of forest across the Earth is a cause for concern - see https://theconversation.com/how-forest-loss-has-changed-biodiversity-across-the-globe-over-the-last-150-years-140968    

Ancient Trees A recent report has emphasised the importance of protecting and preserving ancient trees.  Ancient (veteran) oaks can live in excess of a thousand years, as can Yews.  The Bristlecones of California and Nevada may live for some five thousand years ! Such trees represent a massive carbon store; the carbon dioxide from the atmosphere being locked away for a millennium or five!  Not only are such trees a significant carbon store but they also offer a home or food for many other species - fungi, epiphytes such lichens & mosses, plus larval and adult stages of insects, birds and mammals.  As such they localised centres of diversity that contribute to ecosystem stability.  Not only are these trees ‘hotspots’ for species diversity but they are also centres of mycorrhizal activity and connectivity.  Mycorrhizae represent the symbiosis between fungi and plant. Plants ‘register’ wounding. When we are hurt, our nerves register the pain through the movement of sodium and potassium ions along the nerves.  When a plant is wounded, calcium ions are known to move in response, travelling from cell to cell, and leaf to leaf.  However, it is now known (through research at the John Innes Centre in Norwich) that this is not the first response of the plant to physical injury.  When cells are wounded they release glutamate, a form of glutamic acid.  This travels along the cell was and activates channels in the cell membranes that allow the movement of the calcium ions.   A bumblebee pathogen. One of parasites of bumblebees is Crithidia bombi.  It is a protozoan (single celled animal) that reproduces in the gut of the bumble bee. When infected with this parasite the foraging behaviour of the bee is impaired, as is its ability to learn.   A colony will suffer from increased worker mortality.  Now research has shown that floral structure may influence the transmission of this parasite from bee to bee.  The length and shape of the petals seems to be a critical factor.  If the bees ‘crawls’ in a ‘tube’ of petals, then it may leave behind some faeces.  If the bee is infected with the parasite, then it will be present in the faeces.  If the flower is then listed by another bee then it runs the risk of coming in contact with and being infected with the parasite.  Plants that have flowers with shorter petals / corollas are less likely to have faeces deposited within them, and therefore less likely to pass on the parasite to the visiting bumblebees.

Ancient Trees A recent report has emphasised the importance of protecting and preserving ancient trees.  Ancient (or veteran) oaks can live in excess of a thousand years, as can Yews.  The Bristlecones of California and Nevada may live for some five thousand years ! Such trees represent a massive carbon store.  The carbon dioxide from the atmosphere being locked away for a millennium or five!  Not only are such trees a significant carbon store but they also offer a home or food for many other species - fungi, epiphytes such lichens & mosses, plus larval and adult stages of insects, and a variety of birds and mammals.  As such the are localised centres of diversity that contribute to ecosystem stability.  Not only are these trees ‘hotspots’ for species diversity but they are also centres of mycorrhizal activity and connectivity.  Mycorrhizae represent a symbiosis between fungi and plant. Plants ‘register’ wounding. When we are hurt, our nerves register the pain through the movement of sodium and potassium ions along the nerves.  When a plant is wounded, calcium ions are known to move in response, travelling from cell to cell, and leaf to leaf.  However, it is now known (through research at the John Innes Centre in Norwich) that this is not the first response of the plant to physical injury.  When cells are wounded they release glutamate, a form of glutamic acid (an amino acid).  This travels along the cell wall and activates channels in the cell membranes that then allow the movement of the calcium ions. A bumblebee pathogen. One of parasites of bumblebees is Crithidia bombi.  It is a protozoan (single celled animal) that reproduces in the gut of the bumble bee. When infected with this parasite the foraging behaviour of the bee is impaired, as is its ability to learn.   A colony may also suffer from increased worker mortality.  Now research has shown that floral structure may influence the transmission of this parasite from bee to bee.  The length and shape of the petals seems to be a critical factor.  If the bees ‘crawls’ in a ‘tube’ of petals, then it may leave behind some faeces.  If the bee is infected with the parasite, then it will be present in the faeces.  If the flower is then visited by another bee then it runs the risk of coming in contact with the faeces and being infected with the parasite.  Plants that have flowers with shorter petals / corollas are less likely to have faeces deposited within them, and therefore less likely to pass on the parasite to the visiting bumblebees.

It is depressing to pick up a paper or turn on the news to be met with a catalogue of distressing and difficult stories.  There is also the overarching problem of global warning and climate change.  Only recently, there have been reports of flooding in Sydney after torrential rain, fires are springing up again in Colorado and other States, and India experienced a heat wave (combined with a drought), with some cities experiencing temperatures of 40o+C.  This has resulted in the deaths of individuals, and as the heat wave occurred in the final weeks of the wheat growing season it has killed many crops before harvest.  In Balochistan, the peach and apple harvest has been severely impacted. Here in the UK, there are a number of problems, indeed we have been described as “one of the most nature-depleted countries in the world”.  We have lost plant and animal species, such losses could lead us into an ‘ecological recession’. This occurs when ecosystems systems lack the diversity needed to function well. Much of the damage to (or loss of) our ecosystems is associated with the industrial revolution followed by the  intensification of mechanised farming. The 1950’s and 1960’s witnessed the loss of vast tracts of hedges and the removal of small copses to increase the area for farming / food production, and allow the use of heavy duty mechanised machinery.  There was also the extension of road networks - motorways etc. and urban sprawl /development.  Though woodlands and forests were being eroded long before the industrial revolution; woodland, forest and pasture covered much more of the land than now. There were areas of ‘wilderness’ that were home to animals and plants that have long since gone or are now very rare - ranging from wolves, bears, to beavers and red squirrels. Whilst woodlands were and are havens for many plant and animal species, meadows and pastures have suffered too.  The PlantLife charity has suggested that the UK has lost some 97% of its wildflower meadows during the course of the last century and what remains could be under threat. Lowland meadows are rich sources of biodiversity, both plant and animal, they also store carbon in the soil and ‘knit’ the soil together, so that it is not subject to erosion. [caption id="attachment_38489" align="aligncenter" width="700"] A meadow, partly mown and partly 'wild'.[/caption] Many species are dependent on these habitats, but with the expansion of agriculture and construction of motorways - the landscape has become fragmented and many species cannot across the formidable barriers.  The Scottish primrose is now only to be found on the north coast of Scotland and Orkney, and some orchids are described ‘as just hanging on’.  Species like the common blue butterfly is reliant of bird’s foot trefoil, Greater Bird’s-foot-trefoil, Black Medick and white clover for food for its caterpillars.  The great yellow bumblebee is sadly now one of the rarest British bumblebees. It is limited to flower-rich areas in the Orkneys, Caithness and Sutherland. It is particularly associated with red clover. It is a large species, and was once widespread across the U.K. Creating space and opportunities for wild flowers has been PlantLife's foremost objective from “No mow May”, “Save nature on our roadside” (see the woodland blog here and here) ’Fight for sites” all of which aim to increase the number of sites for wild flowers and their pollinators to flourish.  The Scottish Government has been helping establish wildflower meadows at some of its national nature reserves - notably St Cyrus, Flanders Moss and Forvie, and they are working with PlantLife to create an action plan for Scotland’s grassland.  It is keen for farmers to be involved, offering areas of wild flowers on their farms.  By increasing the areas in which wild flowers (and their associated insects) can flourish, the connectivity can be restored (at least in part).  The creation of biological corridors allows plants and animals to move, which is particularly important in these times of climate change.  

The European hornet (Vespa crabo) is an eusocial insect.  That is to say, hornets live in colonies, with some 200 / 400 individuals in each colony.  A colony is founded by a fertilised queen, who emerges from hibernation in spring. Hornet queens are the sole survivors of an old colony after  a UK winter and they emerge as the weather finally starts to warm in early spring.  They then seek a warm, dry place to start nest construction. Once a nest location has been secured, they lay eggs that hatch into larvae.  The larvae are fed on protein-rich food (chewed up insects) and then they pupate; undergoing metamorphosis [a complete reorganisation of the body].  An adult hornet worker then emerges from the pupa some two weeks later.   These are ‘sterile’ female workers, who take over nest building and collecting food for the next set of developing larvae.   The developing colony lives within the papery nest its a (a bit like papier mâché), adding to the structure as the colony grows.  Twigs, bark and other plant material is broken up, chewed and shaped to form the nest. This material is glued together by their saliva.  Larvae that hatch in the summer are either fertile queens or males.  The males (drones) do not contribute to nest building, food foraging etc.  But in autumn, the males (drones) and the new queens leave the nest to mate.  The fertilised queens hibernate over winter, emerging in spring to start a new nest.  The ‘sterile workers’ and the male hornets die with the onset of winter. In other colonies of social insects, like honeybees, female workers don’t reproduce due to the pheromones that are released by the Queen. This was thought to be the case for European hornets but instead worker hornets enforce ‘sterility’ by physically destroying any worker-laid eggs or the workers laying them ! The food of a hornet is surprisingly varied. They can hunt and capture a wide variety of invertebrate prey (beetles, wasps, moths, dragonflies, robber flies - they may even prey on honey bees).  In many ways, hornets are useful in that they predate on a number of  garden and agricultural pests. Much of this prey is then chewed up to feed the growing larvae.  In return for this material, the larvae willingly ‘exude’ for the adults  a sugary liquid for them to feed on. Adults can also be found feeding on sugar-rich sources such as tree sap, nectar, and ripe fruit. They are more likely to ‘scavenge’ food at the end of summer into autumn rather than hunt.  The head of the insect has dark, prominent eyes, its wings are a reddish-orange, whilst the abdomen is striped with yellow and brown.  Hairs are present on both thorax and abdomen but they are not ‘hairy’ like bumblebees.  The colour of hornets can vary and a number of regional colour forms are known across Europe.  Worker hornets are about 25 mm in length, whilst queens may be up to 35 mm., so significantly bigger than wasps.  Partly because of its colour and size, a hornet can be mistaken for the Asian Giant Hornet (previously reported on in the woodlands blog).  However, a recent report indicates that the european hornet can attack and kill the Asian Hornet, by biting its head off.  Asian hornets are a considerable worry as they attack and kill  honey bees, plus their venom can induce life threatening anaphylactic shock. Breaking news : Asian hornets seen in Essex.   https://www.independent.co.uk/climate-change/news/asian-hornet-uk-bees-insects-b2177217.html In the past, the European hornet was rarely seen in the UK, being largely confined to areas of central southern England, but it has expanded in range in more recent times and is to be found across the South East and even in some more northerly locations.  Female hornets (but not males) have a stinger.  The venom within the stinger contains mixture of various neurotransmitters (serotonin, dopamine, histamine) as well as a concoction of enzymes.  Best avoided !  

The decline in insects numbers, especially pollinators is a cause for concern.  Insect numbers have fallen as natural ecosystems have been lost or disrupted by the expansion of farming and urbanisation, plus the increased use of pesticides and herbicides. The loss of insects not only affects the pollination of many commercially important plants, but also affects the animals and birds that feed upon insects.  So, there are knock on effects throughout food chains and ecosystems. Plantlife has launched a number of initiatives, such as  No Mow May,  Transforming Road Verges Saving Meadows to help offset the decline in insect numbers.  Now work done in Professor Goulson’s laboratory at Sussex Univeristy by Janine Griffiths-Lee (a PhD student) suggests another approach to increasing insect / pollinator levels in urban settings.  Her research has demonstrated that creating a small patch of wild flowers in gardens can go some way to address this fall in insects numbers.    She and colleagues managed to enlist the help of some 150 volunteers distributed across the UK (many were members of the Buzz Club*). Each volunteer set aside a wild flower area  - a mini-meadow (two metres by 2 metres).  Some  of the volunteers then sowed the mini-meadow area with a commercial seed mix of wild flowers, others sowed a seed mix designed / thought to be ‘beneficial to pollinators’. A third group did not receive wild flowers seeds but were asked to set insect traps and record insects in their gardens in the same way as the two ‘wild flower seed groups’. The results were interesting and revealing. The mini-meadows proved to be resource-rich habitats, with an increased numbers of wild bees, more bumblebees, solitary bees and also wasps (when compared to the control group with no wild flower seed sowing).  There were differences in the insect populations for the two groups of seed.  The commercial mix attracted more solitary bees and bumblebees, whereas the ‘designer mix’ of seeds attracted more solitary wasps.  There was no difference in the number of hoverflies that visited the two types of wild flower rich mini-meadows.  Solitary wasps, whilst not pollinators, are important in that they prey on a number of insect pests of fruit and vegetables. Clearly, the planting of small areas in gardens with wild flowers could do much to encourage the numbers and variety of insects / pollinators visiting (or possibly help control the damage done by insects pests).   * The Buzz club is a citizen science initiative.  The UK has a tradition of using the enthusiasm of volunteers to collect data for ecology research.  The Buzz Club projects are focused on gardens - see here.  Membership of the Club is free and the research projects are generally involve no cost.  You might be asked to supply simple equipment or to cover the cost of sending samples back to the club based at Sussex University. Should you sign up then you will receive : A ‘thank you’ email from the team! Information direct to your inbox of new projects being planned. A newsletter about what your data is telling us.  Professor Goulson has previously written a blog about bumblebees for woodlands.co.uk

The UK has experienced some of the highest temperatures ever recorded in recent weeks, and in some parts of the country this has coincided with very low levels of rainfall.  It was the driest July on record for East Anglia, southeast and southern England, according to provisional statistics from the Met Office.  July was also the first time the UK exceeded temperatures of 40°C: on 19 July during an intense heatwave.   These conditions are not without their effects on wildlife.  Whilst warmth can accelerate plant growth and development, and also speed up insect life cycles, but the recent very high temperatures have significant effects, for example:  Drying of the soil As the soil dries, so earthworms burrow down deeper.  Insects, woodlice, spiders, etc avoid the surface of soil, hiding in litter so birds like song thrushes, robins and blackbirds struggle to find something to eat. Consequently, they are less likely to produce a second brood of chicks. This scarcity of invertebrates also affects ground feeding mammals, like hedgehogs (and badgers in more rural locations). Wetland areas dry out; for example grazing pasture that floods in winter - like the Ouse Washes.  This makes it difficult for birds to find food. Lack of water for plant growth Reduced rainfall and high rates of evaporation from the soil (and plants) mean that there is considerably less water available for plant growth.  The growth of leaves is reduced so that there is less material for caterpillars and other insects to eat.  With fewer leaves , there are also reduced surfaces for butterflies and other insects to lay eggs. High temperatures High temperatures and lack of water can affect many animals (including us). Rivers are running at very low levels and some have more or less disappeared.  DEFRA’s latest assessment of principal salmon rivers, such as the River Test shows that 74% of rivers in England are now ‘at risk’. The Environment Agency has noted the flow rate in the Waveney as 'exceptionally low', while other rivers in East Anglia like the Great Ouse  the  Yare, and the Little Ouse are described  as 'notably low'. The young of birds like swallows and swifts are at risk of fatal overheating (the young and old of various species are often more susceptible to heat stress).  Bumblebees cannot forage at high temperatures. Their bodies are covered with ‘hairy coats’ so they can fly when it is cool; but these become a burden in hot spells.High temperatures also shorten flowering time, and hence the availability of pollen and nectar for pollinators (bees, bumblebees, overflies, butterflies). Wild fires. [caption id="attachment_35352" align="aligncenter" width="650"] Woodland recovering from a fire[/caption] High temperatures increase the risk of wild fires, especially on moorland and heathland.  These fires can spread quickly and over wide areas. Young chicks (e.g. Dartford Warblers), eggs, snakes, lizards, small mammals, dragonflies and butterflies are lost.  Accumulated nutrients and stored carbon are lost from the ecosystems. The site of Springwatch Wild Ken Hill in coastal Norfolk suffered an intense fire during the recent hot spell.  The area is home to turtle doves, the grasshopper warbler and other rare birds.   It is hoped that most escaped but mammals, reptiles and amphibians, late-nesting and juvenile birds may not have fared well.   Grassland and woodland fires have also been reported at various sites across the country.  The UK is not alone in facing these problems, Spain, Italy, Portugal, Greece, France and Germany have all lost many thousands of hectares to wildfires. [caption id="attachment_38699" align="aligncenter" width="700"] what was once was grass .....[/caption]