Runner bean exports are one of Kenya’s most important horticultural earners. When runner bean flowers, are pollinated by insects, the resulting pods are larger, better shaped, and more nutritious.
Cowpeas and pigeon peas are widely grown by small-scale farmers in East Africa and are especially important in rural areas for domestic consumption. Runner beans, cowpeas, and pigeon peas are almost entirely dependent on pollinators.
Legume crops have a specialised pollination system involving wild bees that allows pollination to take place only when the flower is ‘tripped’ by the bee. The flowers are bilaterally symmetrical, and when the bee lands on the flower it has to use its weight, or legs, to ‘trip’ the flower. Tripping the flower involves spreading a part of the flower called the keel. This leads to the anthers being exposed and the visiting bee being brushed with pollen. Wild bee species are the main pollinators of legume crops.