|
|||||||||||||||||||
| |||||||||||||||||||
{picture} Bee in my 'Bee Catcher' awaiting removal of pollen.
In January 2005 I set about testing my hypothesis that 'Early in the year, insects benefit from pollen of various willow species.
In last edition when I discovered that the most common Willow, Salix caprea, Goat Willow, was in blossom in mid January, I was TOO LATE to make my observations of the bees. (This year flowering was much later!) However other willows were not yet in flower. I needed to research the flowering dates of the most common willows. More detail later.
To the practical beekeeper, - the factors governing the activities of the bees are: the climate - i.e.: the ambient temperature and weather conditions, the number of bees flying, and the source and quality of the pollen / nectar being collected. I needed to start observations in David's apiary and to produce a table for my thesis. I set up a thermometer and ascertained the direction of the hive opening. I kept a diary about weather conditions, number of bees flying, and the colours of the pollen loads being collected.
I visited the apiary every two or three days, around midday. I found that David's bees were docile, and when the temperature was over 50°C they would venture out and did not object to me peering closely at their legs when they returned to the hive! (Academically I had to record the temperature in Degrees Centigrade - although I am happier with 4l°F than 5°C.)
I went round to the apiary on my bike, with my bee catcher, a stopwatch, a lidded jar, a paintbrush, piece of card to cover the top of the jar, and a notebook and pencil.
I made a note of the temperature and the weather conditions, estimated the % of bees bringing in pollen and the rate at which they were returning to the hive. It was difficult to be accurate! When the weather was cold I was distressed to see some struggle and die before reaching home.
My Method of pollen sampling
To sample pollen, bees were trapped as they approached the alighting board and the top of the beaker covered by a card. The bee was then shaken into a sample jar with a screw top lid. When I first started my observations I would take the jar with bee into David's shed and transfer the pollen, releasing the bee to return to the hive. This worked well at first, but later I found the bees too excited at being robbed of their hard earned loads of pollen, and very difficult to control.
After a few mismanaged captures, I discovered that it was easier to return home, put the bee in jar in my fridge at 5°C for five minutes. When they were sleepy, it was possible to then gently remove the pollen off their legs, with a dampened paintbrush. The pollen was transferred to a small sample jar, labelled with the time and date. The bee was put in the warm sun, on the windowsill until she seemed happier. It sounds easy! - IT WASN'T!
I then cycled back to David's to return them to the hive. Quite a performance! The pollen was put into a labelled sample bottle and kept in my freezer for later examination.
During March I noticed a field of Oil Seed rape, just showing yellow, about a 1/4 mile from the apiary. It was to be ominous.
On the 16th March, arriving at the apiary, (I was not protected by a bee suit or veil- it had not been necessary until this point) the bees were flying in full force; they were very agitated, around my head, and very threatening. I returned the next day fully protected from their attentions!
I continued sampling with more care after that!
WILLOWS
Their delights and value to all insects.
Alongside all this excitement at the apiary, I was also required to collect data on the flowering dates and properties of local willows.
I carried out a review of literature on them, starting with a wonderful book by John Evelyn, (advisor to King Charles 2 on Royal Forests) written in 1664! who wrote then "If some (the willows) be permitted to wear their tops five or six years, their Palms will be very ample, and yield the first, and most plentiful relief to Bees, even before our Abricots blossom" I soon realised that even after all this time there is a lot of confusion about the species. I had a lot of learning to do. I was touring the countryside around Eastham (on my bike) recording the dates at which I saw catkins on various willows.
Luckily willows are my favourite trees and I really enjoyed studying them.
As briefly as possible: willows are 'dioecious', which means that each individual tree is either male or female. Both female and male catkins have nectaries and are a rich source of nectar, HOWEVER the male catkins bear copious pollen, (very beautiful they are too!) which supplies the protein that is so vital to feed the young brood in spring. It is a pity that the willow most commonly favoured by gardeners is the 'Weeping willow' (Salix x Crysocoma).
This tree is only available as a female clone, and as such does not produce the protein rich pollen. (I never cease to be amazed at the similarities between all living organisms, babies need to be fed protein rich food in the form of milk and even young emergent seedlings get their protein from the seed itself.)
My next task was to construct another table to show the flowering dates of male and female varieties of willow and the length of time the flowers persisted. Examples were - Goat willow from mid-January, Crack Willow from March, and White willow still in flower in May, when I completed my study.
Bringing my research to a conclusion was the most frustrating part. I was able to mount my pollen samples and prepare slides from each day's collection.
I am no palynologist. I tried with the aid of Dorothy Hodges book and help from college technician to source the pollen; my guess after examination of the slides was that the bees gathered hazel in mid January, and oilseed rape in March. My research was certainly very indecisive but my tutor reassured me that at this level I only needed to prove that I could construct a reasonable research project and carry it through to produce a well-argued discussion with conclusions. I needed to suggest ideas for improving the experiment, and possible avenues for future research.
My beekeeping friends will be interested in this study for confirmation that honeybees gain great benefit from a source of early pollen. One has only to stand in the warm spring sunshine when the 'pussy willows' are in bloom to enjoy the sight and sound of honeybees collecting nectar and pollen. I gained much insight into willow, one of our most amazing trees without doubt, (but that would be another article in itself.)
Mankind has never really valued the contribution to the eco-system of all the insects; their vital role in pollination, and their role in the food chain for the birds, and invertebrates. The continued use of pesticides has had a disastrous effect on nature's balance.
I always felt that oil seed rape was a mixed blessing (indirectly leading to my demise as a beekeeper) I feel sorry for the bees - they seem to be given an almost impossible task - on top of all the other pollinating jobs that I seemed to me more important - MY APPLE TREES AND RUNNER BEANS! Now, last year we had local oil seed rape as an October crop. I wonder how this will affect the honeybee's life cycle? The queen will surely not be able to respond to the late pollen source by starting to lay again? It seems a very worrying scenario to me, what do you think?
Another interesting aspect of willow growing is the Short Rotation Cropping used as an alternative fuel source for electricity power stations.
Already quite successful in Denmark, and being trialled in U.K. there is an opportunity to benefit insects and the ecosystem. Maximum quantities of pollen would be produced at a favourable time for insects by careful management of the coppices, using a mixture of male willow varieties chosen for early and extended flowering. As an alternative flowering crop in modern farming, coppicing could provide a rich habitat where none had existed before.
My studies provided me with much food for thought and continues to excite my imagination. I hope you have been interested, too?
Sylvia Briercliffe
Latest Articles:
Archive Articles:
©2007 Cheshire Beekeepers' Association