This is the fifth post in a six part blog series about rare insects in the Cairngorms. A new project launched this year to save six endangered invertebrates in the north of Scotland and project officer Gabrielle Flinn will take a closer look at one of these species each month. This time, it's the turn of the small scabious mining bee. The Rare Invertebrates in the Cairngorms project is a partnership involving RSPB Scotland, the Cairngorms National Park Authority (CNPA), Buglife Scotland, Butterfly Conservation Scotland and Scottish Natural Heritage (SNH).
Photo credit: Peter Stronach
A small bee, around 7 millimetres in length, which has a thorax covered in golden hairs sits on top of a beautifully rich, violet-coloured head of a devil’s bit scabious flower (Succisa pratensis). Here, she gathers and stores white pollen on her hind legs, making the bee look like she’s wearing white cowboy chaps.
It’s a cool day, around 14 degrees Celsius so she takes her time due to having a little less energy. Once it starts raining she will go underneath the flower head to shelter herself before flying back to the nest when there is a moment of clear weather. Upon reaching the nest, which to the outsider looks like a small volcano-like hole in sandy soil, she will land just short and observe the entrance to her home for a few seconds – checking for danger perhaps – before entering. There, she offloads the pollen harvest, a meal for the larvae that will one day hatch out of eggs laid in the nest, before setting off again to forage.
Very little is known about the small scabious mining bee (Andrena marginata) - least of all about its distribution within the Cairngorms National Park. This bee is one of Scotland’s rarest, being found only in a small number of sites in the Highlands and is known to be threatened in the rest of Europe too. It survives by collecting nectar from a small range of wildflowers but relies entirely on Devil’s bit scabious as its source of pollen which provides protein.
Many insect species have evolved to be very specific in their habitat and food selection to avoid competition from other foragers. However, in a world where the natural environment is deteriorating and more of these niches are facing serious threat, it is specialists such as this bee which are suffering the most. Some ask why we should be striving to protect creatures as small and unassuming as the small scabious mining bee. However, it is the smallest and most hidden of organisms that we should be concerned about because their plight is not in plain sight, yet, may have the harshest costs.
The bee is a component of the diverse biological network within the Scottish landscape that keeps our ecological systems going. Without this diversity and the pollination services provided by bee species, we would have a weaker, less resilient environment which can also have catastrophic consequences on human life.
As a rare species and a champion for wildflower-rich habitat, the bee made it on to the list of six insects which direct the efforts of the Rare Invertebrates in the Cairngorms (RIC) project. Over the next three years, this project aims to find more sites where this bee exists and work closely with landowners to protect these sites. In this first year, RIC volunteers have already found three new sites for the bee and have filmed the bee entering and exiting its nest – a first in Scotland. The project is now working with land owners on which the bee was found with hopes to ensure the protection of the species.
If you would like to keep up to date with the RIC project, you can find updates on Facebook and Twitter.