By Mary Hearty
Pollinators play an important role in ecosystem services including supporting sustainable food production, ecosystem stability, habitat conservation, and creation of opportunities for income generation.
However, conservationists indicate a decline in abundance and diversity of wild pollinators and a threat of extinction for 17 percent of pollinators such as bees if the trend continues.
“We have experienced colony losses in the last two decades hence this has raised a lot of concern on food security in the future. Besides, honeybee health has become a key topic in agricultural research thus thrusting pollinators and pollination in the limelight,” Elliud M. Muli, Senior Lecturer of Agricultural Entomology and Apiculture at South Eastern Kenya University said during a virtual symposium on Pollinator Health held by Agrochemicals Association of Kenya.
Pollinators provide pollination service to plants which is needed in boosting agricultural production, and it has been estimated that 87.5 percent, which is approximately 308,000 species of the world’s flowering plants depend, at least in part, on animal pollination for sexual reproduction. They include apples, cherries, pumpkins, cucumbers, blackberries, tomatoes, sunflowers and soybeans, among others.
One of the reasons why pollinators are declining is because we are having intensive agricultural management and land fragmentation. We want to use machinery to plough our land and as a result we destroy ground nesters, notes Dr. Mary Guantai, Kenya Plant Inspectorate Service (KEPHIS).
Other factors include land use such as planting one type of crop and real estates, poor appreciation and inadequate knowledge of bees, parasites, diseases, natural calamities like flooding, drought and fires as well as improper use of pest control products.
“When we spray our crop at the wrong time for instance, during the day when the pollinators are very active, they have very lethal effect on bees,” Dr. Guantai explained.
Besides, environmental pollution including lack of clean water, food, and climate change have as well influenced the decline of bees.
Pollinators comprise a diverse group of animals dominated by insects, especially bees, some species of flies, wasps, butterflies, moths, beetles, weevils, ants, midges, bats, birds, primates, marsupials, rodents and reptiles.
She said: “More than 90 percent of the leading global crop types are visited by bees and around 30 percent by flies, while the rest of the pollinators visit 6 percent of the crop types. Globally, there are approximately 20,000 species of bees with sub-Saharan Africa recording about 3000 species and around 400 to 500 species in Kenya.”
Pollinator-dependent crops have increased by 300 percent over the last five decades. However, they have experienced lower growth and lower stability of yield than pollinator independent crops such as cereals and root crops.
Value of pollinators and pollination
Dr. Guantai said pollinators contribute to healthy human diets and nutrition as well as better livelihood through beekeeping, honey hunting, and food production. “People are able to make a living from selling honey,” she said.
Additionally, pollinators contribute to medicines, biofuels like canola and palm oil, fibers such as cotton and linen and construction materials, among others.
She explained that in terms of the value chain, pollination impacts various value chain levels across different crop sectors including household level, community, nationally, regionally and globally.
“At the community level, we are able to increase our sales, as a result, this helps in bargaining for better markets for our produce resulting to increased trade,” Dr. Guantai said.
“Nationally, some studies carried out by the Ministry of Agriculture, Livestock and Fisheries reported that 45 percent of the crops dependent on insect pollination contributed more than 65 percent of the national GDP. In addition, the pollinators were responsible for about 11 percent of the national crop GDP. “
Furthermore, the contribution of insect pollinators to crop production in Mau, Cherangany, and Mt. Elgon were estimated at 314 million, 67 million, and 549 million respectively. And in absence of pollinators, some crops may not have fruits or seeds. For example, pumpkins and water melon have been found to record up to 99 percent loss.
Globally, countries are currently funding pollination programmes to improve provision by bees and other specialized pollinators.
In order to manage the pollinators, their nesting sites like the soil, dry twigs, and woods need to be protected. “We need to avoid leaving land bare and practice minimum tillage to conserve the ground nesters; we need to leave dead and decaying wood around farms so that carpenter bees can drill through to make nests,” Dr. Guantai noted.
Another management strategy is protecting pollinator food resources by planting hedgerows around farms; use of patches and setting land aside to provide plants that flower at different times of the year; crop rotation as this enables bees to utilize different plants for different nutrients; and practicing diversified farming system such as home gardens, agroforestry, and mixed cropping.
Also, there is need to adopt farm practices that are friendly to bees. These include avoiding indiscriminate use of pest control products especially when plants flowering, and seeking alternative forms of pest control such as bio-pesticides and adopting integrated pest management method.
June Aluoch, Pest Control Products Board (PCPB) who was also present during the session, urged international organizations and foreign national governments to initiate intergovernmental dialogue with the national government in addressing global pollinators decline.
She encouraged researchers to focus on relevant research that will form the basis of decision making and policy formulation for government agencies such as assessing the pollinator status in Kenyan context, identifying priority areas and recommending strategies to reverse, reduce and avoid pollinator decline.
“A lot of research has been done on pollinator health however, there is a gap between policy and research since they are not included when making policies,” she said.
Aluoch also advised business entities such as Agro and Chemical companies to provide data requirements for bee risk assessment, and to ensure proper communication and precautionary statements are placed on agro-chemical packages to inform the user with regards to possible risk to bees and risk mitigation measures.
Pollinators business associations and interest group also need to identify platforms of inclusion and actively take part in the dialogue with government and intergovernmental partners to address pollinator resilience concerns and contributes their experience-based knowledge and view towards addressing pollinator health concerns, she added.