The period since WW2 has seen urban areas and, indeed farms, expand across the UK. The number of places where wildlife can thrive has been eroded.  Gardens and lawns have been changed to provide parking for cars, lawns are mowed and ‘weed-killered’, or worst still replaced with artificial grass so there is not a weed in sight.  Fortunately there are now initiatives like No Mow May that promote the growing of wild flowers in lawns and public spaces, like roadsides and verges.  Many common weeds are simply wildflowers by another name. Wild flowers / weeds (like dandelions, ragworts, clovers) are a lifeline for bees and bumblebees - who are facing so many threats [pesticides, habitat loss, invasive species] so adequate food is important. The flowers of these wild flowers / weeds offer food for a wide range of endangered bees, and at times when other resources are limited.  Dandelions, for example, offer an abundant source of nectar and pollen for bees & bumblebees when other options are limited - especially in urban settings. They produce their flowers (and therefore nectar and pollen) from early Spring right through to the onset of Winter. Recent studies have shown that the diet of bees has changed over the years.   In the past, the bees were able to forage and collect pollen and nectar from a wide variety of plants but with the loss of ‘natural’ wild areas their diet is now often dominated by brambles, clover and dandelions.  In the case of dandelions, their simple, open flowers makes for ease of collection.  They are visited by honey bees, bumblebees and carder bees.   Some studies have indicated that dandelion pollen, whilst it is rich in the amino acid proline,  has low levels or lacks certain amino acids (such as valine and isoleucine).  Bees need the same ten essential amino acids as us.  Without a supply of these particular amino acids, the development and growth of bees is impaired, as is their disease resistance and ability to raise the brood.  So, it is important to find ways to offer our pollinators a range of plants / pollen to provide all their essential nutrients. interesting related papers Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0158117 Shifts in honeybee foraging reveal historical changes in floral resources: https://www.nature.com/articles/s42003-020-01562-4

The diet of bees has changed over the years.   In the past, bees were able to forage and collect pollen and nectar from a variety of plants.  With the spread of highly mechanised agriculture, increasing urbanisation and road network - now their options are somewhat limited.  Large fields of monocultures, for example, of oil seed rape are now common. Whilst oil seed rape is a good source for foraging bees and bumblebees, they need to collect nectar and pollen from a variety of sources so that they get a range of nutrients, such as the essential amino acids.  Without these particular amino acids, the growth and development of bees is affected, as is their resistance to disease and their ability to raise the brood.  It is important that our pollinators are able to find a range of plants / pollen to provide all their nutrients. Whilst wild flowers [aka weeds], like dandelions, ragworts, and clovers are a lifeline for bees and bumblebees, recent research at the University of East Anglia has shown that woodlands can offer important habitats for bees, isuch as the leaf canopy.  The research team studied 15 woodland sites in agricultural areas across Norfolk (in Spring).  Within the woodlands, they looked at the bee activity in  the understorey  the woodland edge  and at different levels in the tree canopy.   They found that bees were active high up in the sunlit tree canopy, and their activity was particularly high near flowering sycamore trees.  Red tailed bumblebees (Bombus lapidarius) were busier in the canopies than elsewhere.  The understorey and woodland edges were also significant contributors to bee activity.  This study emphasises the importance of woodland habitats for the wild bee community.  

The Venus flytrap (Dionaea muscipula ) is a carnivorous plant found in  the wetlands of North and South Carolina in the United States.  The Venus flytrap is also popular as a cultivated plant and an 'object of interest' and can be found in many a garden centre. In the wild, the fly trap is found in areas with nutrient-deficient soils (often low in nitrate and phosphate).  The plant makes up for the ‘edaphic* limitations’ by trapping and digesting insects (and spiders) in their specialised leaf traps. By doing so, they are able to extract nutrients such as phosphorus and nitrogen which are in limited supply in the soil - from the bodies of their prey.   The ‘Dionaea diet’ is, in fact, 33% ants, 30% spiders (which are arachnids - not insects), 10% beetles and 10% grasshoppers - only a small percentage are actually flying insects. Read more...

It has been known for some time that bees and bumblebees are attracted to flowers by their colour(s), scent (volatile oils), shape, nectar and indeed electric fields (see recent post).  However, it has now been shown that bumblebees can pick a plant on the basis of the nutritional content of its pollen. Anthony Vaudo et al at the Centre for Pollinator Research (Penn State University) recorded the foraging patterns of bumblebees in defined outdoor areas, and then determined the chemical make-up (carbohydrate, protein and lipid levels) of the pollen from the different species present.  They found that the bumblebees went for pollen with a high Protein:Lipid value.    Read more...