Pollinators transfer pollen from one plant to another in order to fertiliser them.

Pollinator depletion alarms experts .
Stephen Tsoroti
AGRICULTURAL experts and ecologists have warned that Zimbabwe’s food security situation is facing further threat from the shrinking number of pollinators.
Pollinators transfer pollen from one plant to another in order to fertiliser them.
It’s a category comprising mainly birds and insects such as bees and beetles.
Over the past five decades, it has been observed that crop fields have almost tripled thereby overwhelming the dwindling number of pollinators.
Experts say the current numbers of the species is no longer sufficient to pollinate the available crop fields.
Zimbabwe is therefore on the verge of a pollination crisis in which crop yields may begin to diminish.
This will certainly compound the country’s woes.
It is estimated that Zimbabwe’s maize production dropped by as much as 40 percent in the 2014/15 cropping season with a likely cereal deficit of between one and 1,3 million metric tonnes.
Agronomist, Jonathan Rwodzi, said wild pollinators have gone down over the last 50 years due to the increasing use of pesticides and habitat loss thereby reducing the abundance and diversity of floral resources and nesting opportunities.
“The intensification of agriculture and increasing reliance on pesticides mostly neonicotinoids means that pollinators are chemically exposed to cocktails of agrochemicals,” he said.
A local study of crop systems by the University of Zimbabwe (UZ) showed that a healthy population of wild bees is key to the successful yields of crops ranging from pumpkins to grape fruit.
Maria Goss, lecturer at the UZ Department of Crop Science, who conducted the study, said: “This is uncharted territory. But the research found out that areas where crops like pumpkins were planted with pesticides, the yield was small as compared to areas where there were no pesticides.”
Pollinators provide a key ecosystem service vital to the maintenance of both wild and agricultural plant communities.
The 1999 convention on the Biological Diversity issued the Sao Paulo declaration on pollinators, recognising the critical role these species play in supporting and maintaining technical productivity, as well as the survival challenges they face due to anthropogenic change.
Today pollinators are considered to be in a state of decline with some species, such as the Franklin bumble bee having been red-listed because it is in danger of extinction.
Although managed bee hives are increasing worldwide, they are not sufficient to compensate for the loss of wild pollinators in many locations.
Honey bees are increasingly threatened by an onslaught of harmful influences such as excessive use of toxins and bee-killing crop chemicals; both of which have contributed to the massive bee die-off phenomenon known as Colony Collapse Disorder.
Modern agriculture techniques involving spraying crops with toxic chemicals are also killing the world’s soils, which in turn are killing off the bees that feed on the plants that grow in these soils.
It is a highly destructive cycle of death that could one day make it virtually impossible to grow enough food to sustain human life on earth.
The decline in the health and populations of pollinators pose serious threat to the integrity of biodiversity, global food webs and human health.
At least 80 percent of world crops require pollination to set seed.
An estimated one out of every three bites of food is made possible by the work of animal pollinators.
The quality of pollination service has declined over time and this has led to concerns that pollination will be less resistant to extinction in future.
“It is the pollinating bees’ activity that balances the ecosystem. Bees disappearing will lead not only to fatal rundown of many plant and animal species but also to the reduction of environmental resources. This will have negative impact on the biosphere, such as the air and water pollution; leading to the growth of infectious diseases,” says Pride Machingauta, secretary of Bee Keepers Association of Zimbabwe Trust.
The annual value of honey bee pollination of agricultural crops globally is estimated at 153 billion Euros, according to the International Bee Research Association.
The bees’ contribution to the pollination of forests and wild flora can only be greater.
The United Nations Food and Agriculture Organisation reports that for much of the past 10 years, bee keepers, primarily in the United States and Europe, have been reporting annual hive losses of 30 percent or higher.
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