Fighting factors affecting global bee health is necessary

21Sep 2019
Editor
DAR ES SALAAM
The Guardian
Fighting factors affecting global bee health is necessary

A number of different factors causing global  bee decline   are  now being monitored and investigated such as pests and diseases, bee management, including bee keeping practices and breeding, the environment, including weather-

-agricultural practices and the use of pesticides and the availability and quality .

Bees are flying insects closely related to wasps and ants, known for their role in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey and beeswax. There are over 16,000 known species of bees in seven recognised biological families.  They are found on every continent except Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants.

Some species including honey bees, bumblebees, and stingless bees live socially in colonies. Bees are adapted for feeding on nectar and pollen, the former primarily as an energy source and the latter primarily for protein and other nutrients. Most pollen is used as food for larvae. Bee pollination is important both ecologically and commercially. The decline in wild bees has increased the value of pollination by commercially managed hives of honey bees.

Human beekeeping or apiculture has been practised for millennia, since at least the times of Ancient Egypt and Ancient Greece. Apart from honey and pollination, honey bees produce beeswax, royal jelly and propolis.

With an estimated 75 per cent of human food dependent on the action of pollinating insects, bees are vital for global food production. But their very existence is under threat as they face chronic decline around the world.

A major factor in this decline is the excessive use of pesticides in farming in some regions. And one country where this is increasingly evident is Brazil.

While many European countries have restricted the use of agrochemicals because of the danger they pose to bees — as well as environmental and human health problems — in Brazil almost 300 pesticides have been approved for use on a wide range of crops.

Between December 2018 and March 2019, more than 500 million bees were found dead by beekeepers in four Brazilian states. Beekeepers’ associations and agriculture authorities suspect this was caused by the widespread use of two classes of pesticides .

Recent studies highlight several risks for bee populations associated with the use of these substances.There are around 20,000 species of bees worldwide that pollinate more than 90 per cent of the world's top 107 crops. Researchers say the value of pollination to agriculture provided by bees may exceed U$200 billion per year worldwide.

Brazil is home to up to 5,000 of these species and 85 out of the country’s 141 crops depend on bees as pollinators. A study published in 2017 in Science analysed 33 sites across three European countries where neonicotinoids were used. It found that in Hungary the number of worker bees declined 24 per cent in colonies.

 A second study conducted independently by a Canadian research team and published in the  Science edition, found that western honey bee colonies exposed to neonicotinoids in cornfields for up to four months also had fewer worker bees and sometimes no queen bee.

Pesticides  are highly toxic to African-derived adult honeybees leading to impaired motor function in these pollinators, according to a study published last year in the Annals of the Brazilian Academy of Science. Pesticides are just one of several factors affecting bees around the world. Others are deforestation, urbanisation, climate change, land-use change, habitat loss, disease and invasive species.

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