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Protecting and conserving bees :
Honey bee -nature’s pollinators
By Dhameshi YATAWARA
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A close-up of the bee hive
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Fruits, vegetables, cereal and grain dominate the food we consume.
Any dish, that is sweet, sour, bitter or spicy, is based on these
resources that come from plants. Most of the time fruits or vegetables
just do not come out of flowers. As we all know behind all these flowery
and fruitful plants lies a very magical and technically complicated
process called pollination, a brainchild of Mother Nature.
How do plants get pollinated? Well, depending on geographical areas
it happens in different ways. Wind, insects and other animals are the
main ones. But in most fruiting trees and in certain vegetables the
pollen is carried by animals mostly by insects – butterflies, bees as we
know.
Pollen is the male part of the flower and it needs to be carried away
to the female part of the flower which is called pollination and in most
cases in nature, without pollen plants can not produce fruits or seeds.
The fruits that we eat, the vegetables we use and even most spices are
derived from fruits and seeds of plants would not exist if not for
pollination. This is a necessary part of the reproductive biology of
plants.
Among the pollinators of nature, bees seem to be doing the largest
part of the job. Armed with large number of workers and their ability to
fly long distances bees are the best unbeatable pollinating machines and
humans have not found a successful alternative machine. In the world of
bees living in Sri Lanka, the Bambara (‘Apis dorsata’) is the best
pollinator of all, according to researcher Fred Dyre, Professor of
Zoology of the Department of Zoology of the Michigan State University,
USA. Dyre has been studying bees since his days as a grad student at the
Princeton University, USA. What is there to study about bees is a common
question scientists like Dyre answer quite often. Currently Dyre is in
Sri Lanka to study our ‘Bambara’, the best pollinator among the bees in
the world, as part of long standing research.
“This needs further studies to prove the fact,” he added. Yet they
have several reasons to believe Bambara is the best pollinator. “ In
tropical Asia generally most pollination done by animals and it is
mostly bees. Honey bees have long flight ranges, rapid recruitment,
precise communication, large colonies and thus we think that honey bees
are more efficient as large scale pollinators than other bees of the
world,” he explained. Bambara is the biggest bee and has the longest
flight range. Bambara spread plant genes over a large distance. “this is
important for agricultural plants as well as forest plants,” Dr. Dyre
explained.
“There are thousands of bee species. I learned from Sri Lankan
zoologists that there are 50 – 60 species of bees in Sri Lanka, possibly
more than that. And the group that I study is the true honey bees. And
the honey bees are a group of about ten species. There are many common
features such as complex societies, large ensemble of workers, a queen,
and sterol females. They build wax combs in which they store honey and
raise the larva to continue their colony. They heavily depend on nectar
and pollen from plants as resources. In the process of that they
disperse pollen.
All bees pollinate. But the distance foragers carry pollen and the
number of bees get out there in to the crops or to the forests will
determine the success of their job, according to Dr. Dyre. “And all of
this probably has to do with having a communication system that is very
precise and makes a successful forager to recruit a very large number of
its nest mates to a feeding patch and successfully compete with the
other bees,” Dyre explained. Bees communicating with each other would be
a bit difficult to understand yet it’s a remarkable creation in nature.
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The Bee Team – from left – right : Dr. Siril Wijesundara (DG,
Botanic Gardens Department), Dr. Wasantha Punchihewa, Dr. Fred
Dyre and Nayana Wijetilaka |
As Dr. Dyre explained this feature of bees can be considered as
unique in the animal kingdom. “It is called as the dance language as it
involves movements of the body of a successful forager whose gone out
and found food at a particular location. It returns to the nest and does
these body movements. And by waggling their body in a certain way
pointing a particular direction on the nest and doing it with a certain
tempo it can certainly tell the other bees they should fly relative to
the sun to get to the food and also the distance.
Other bees pay attention to the dancer and after they watched a few
cycles of the dance they go out and look for the food. This
characteristic of honey bees contribute to the other unique features
they display,” he said. According to him this dance language has been
identified by scientists nearly 50 years ago. “I studied deeply in to
this language and tried to understand how bees use the sun and landmarks
as navigational tools.
Trying to find answers to many questions that is with their
language,” he added. The dancer bee is giving out a message of a place
that may be at 5 to 10 kilometres away from the location where they are
communicating. This does not give any signal on the individual bee as in
many signals animals do to find a partner for mating. But the bees are
actually talking of something far way from where they live. “Even on a
cloudy day, where there is no sun to direct the bees, they still
communicate and find their way to food.
They have to learn it over time. They have to learn the particular
pattern to food location,” Dr. Dyre explained. And he is still curious
about it.
Amazingly Bambaras travel in moonlight too. “I did document it in my
research that Bambara bees do go out in the moonlight,” Dr. Dyre said.
“Such that in the night of the full moon Bambara bees actually make more
flights than during the day,” he said.
As he further explained according to research by botanists, flowers
do not produce much nectar during the hot climate of the day time it is
mostly during the cool early morning hours or late in the evening or
night – a typical pattern of tropical flowering plants. “Even the
Bambara colonies a pretty much shut down after ten in the morning until
about three or four in the afternoon. They are very quiet this time
unless they go to collect water to cool themselves,” he explained. “Bees
were believed to be diurnal pollinators but this finding makes their
behaviour more complex,” he added. None of the other bees belonging to
the ‘Apis’ species travel in night only Bambara does. “On full moon days
and other days leading to full moon day the bees keep flying,” he said.
In fact the study of Asian Honey bees has taken place at the
Peradeniya Royal Botanic Gardens in the early 1950’s by research
scientist Prof. Martin Lindauer a student of Karl Von Frisch, who gave
the first inspiration to Dr. Dyre to study on ‘Bambara’ during his study
at Princeton University.
There is a unique place at the Peradeniya Gardens which was the study
centre for Asian Honey bees and it is a tree with lots of Bambara
colonies called the bee tree.
This tree which is actually a ‘Hora’ tree (‘Dipterocarpus’ sp.) is
still there in the Garden standing nearly a half a century bearing an
amazing part of the Sri Lanka bio diversity. The first picture of this
tree has appeared in 1951 in the research paper by Prof. Lindauer.
“According to our counts we observed nearly 25 colonies,” Dr. Dyre
explained. As he further explained during a research in India he has
observed 108 colonies in a Banyan tree.
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The tree – the bee tree in Peradeniya Royal Botanic Garden. It
is a Hora tree (‘Dipterocarpus
sp.’) that has been full with bees and hives for many years |
“They aren’t the only bee to make honey. Even the tiny ‘Kona mee’ the
small stingless bee commonly found in Sri Lanka also produce honey in
tiny amounts.
But honey bees make large amounts of honey and Bambaras can make up
to 20 – 30 kg of honey a year in one colony,” Dyre explained revealing
an unknown fact about our sweet honey bee the ‘Bambara’. What is the
importance in Sri Lanka? Dr. Dyre explained that first of all because
tropical Asia is believed to be where the honey bees evolved and got
diversified. According to him Sri Lanka shelters about three species of
true honey bees.
There are Solitary bees too. They are those who do not reproduce in a
community or do not form a stable social group. There is just one female
bee, mate with one male bee and raise the young on her own.
She builds a nest on her own, brings pollen and feed the offsprings.
It is not a colony. For example in Sri Lanka the bees in the Family of
‘Megachilidae’ are such solitary animals.
In USA sweat bees fall in to this category. Another group of solitary
bees found commonly in Sri Lanka falls in to the Family of
‘Anthophoridae’ which includes bees some of which nest in the ground.
A very conspicuous member of this group that lives in Sri Lanka are
the so called ‘Carpenter bees’. They build a tunnel in the wood and can
be commonly found in old wooden buildings – the big black bees. Deeper
in the wooden tunnel the female lays her eggs and deposits the pollen
and builds a series of cells and in each cell there is an offspring.
“So far bees do not face severe threat to their existence but
unexplainable fear leads to these bees being killed and that is a major
threat,” Dr. Dyre explained. “In USA since 2006 bees are facing ‘die
back’ syndrome which is believed to be caused by a pesticide. A large
number of bee keepers started losing their industry on a mass scale and
still research is on going to find the true reason,” he explained.
The identified pesticide makes the bee to lose its direction to
return to its hive, according to research. These are possibilities that
can happen as we humans develop. To protect the valuable pollinators in
Sri Lanka, the Ministry of Environment established a Working Group of
Pollinator Conservation that comprises the country’s top botanists and
zoologists.
The Working Group is headed by Dr. Wasantha Punchihewa who is a
leading researcher on Sri Lankan bees. Dr. Punchihewa is also involved
in promoting the bee keeping industry in the villages under the ‘Divi
Neguma’ program that is conducted under the Economic Development
Ministry. The Working group is working on conserving all pollinators of
the animal kingdom and specially the Bambara bee which is facing threats
in places like Sigiriya and several other public places where there are
a large number of hives. |
