Drop in bee population strikes Sri Lanka’s food sector: Expert

By Charithya Kumarasiri   

Sri Lanka’s agricultural sector is being urged to adopt more bee-friendly farming practices as experts warn that the decline of pollinators could threaten food production, increase cultivation costs and reduce farmers’ profits.   

The contribution of bees to food production is significant. According to the Department of Agriculture, bee pollination can increase harvests by 20% to 70%. However, bee populations are increasingly under threat due to modern agricultural practices, habitat destruction and excessive pesticide use. The expansion of large-scale cultivation and the suppression of natural vegetation have reduced bees’ natural habitats, while uniform agricultural landscapes fail to provide the diverse diet insects require for survival.   

According to P. Sisira Kumara, Director of Extension and Training at the Department of Agriculture, many farmers tend to use highly toxic chemical pesticides and fertilisers in the expectation of achieving higher yields, despite the harmful impact on pollinators.   

Studies show that exposure to pesticides can reduce the lifespan of bees, affect their ability to return to the hive, interrupt egg-laying by the queen bee, disrupt communication among worker bees and even paralyse their wings and legs. These effects weaken entire colonies and may ultimately lead to the collapse of hives.   

The reduction in bee populations has already created additional economic burdens for Sri Lankan farmers. With fewer pollinators available naturally, farmers are being forced to carry out manual pollination, significantly increasing labour costs. P. Sisira Kumara pointed out that crops such as passion fruit, pumpkin and watermelon require daily manual pollination when bee activity is insufficient.   

“For one acre of passion fruit cultivation, at least one labour unit is needed daily for manual pollination,” he said. “This becomes an extra production cost that reduces farmers’ profits.”   

To address this issue, the Department of Agriculture is promoting environmentally friendly farming methods, including Good Agricultural Practices (GAP) farming systems, which aim to minimise harmful chemical use. The Department is also encouraging farmers to install bee boxes on cultivated land during the flowering season to improve pollination rates. Recommendations include installing two to four bee boxes per hectare for pumpkin cultivation, three to five boxes for passion fruit, one to two boxes for sesame and two to three boxes for bitter gourd cultivation. Farmers are also being advised to avoid chemical fertilisers and pesticides during flowering periods or to use less toxic, mild alternatives whenever possible.   

In addition to commercial agriculture, authorities are promoting the cultivation of bee-friendly crops and plants, such as mango, cucumber, banana, brinjal, coffee, roses, and sunflowers, in home gardens to help create habitats and food sources for bees.   

Meanwhile, initiatives are also underway to promote stingless bees, commonly known as “kanei massa”, primarily to encourage pollination. P. Sisira Kumara noted that while stingless bees produce small quantities of honey, which is quite expensive, they are mainly being promoted to ensure pollination.   

Globally, bees are recognised as one of the most important pollinators in agriculture. Around 90% of vegetable pollination depends on pollinators, with bees playing the leading role. According to the Food and Agriculture Organisation (FAO), out of 100 crop species that provide 90% of the world’s food, 71 are pollinated by bees. It is estimated that bees pollinate nearly 70% to 75% of agricultural crops worldwide, and account for 75% to 80% of the pollination of fruit trees. Beyond increasing yields, bee pollination also improves the quality of produce by enhancing characteristics such as fruit size, shape, sugar content and acidity.