The importance of native bees, especially cactus bees (Diadasia spp) in the pollination of cactus pears

Abstract

The edible pulp size of cactus pear fruit is highly correlated with seed content, which in turn is correlated with the effectiveness of pollination. In California commercial orchards, honey bees (Apis mellifera) are not nearly as efficient pollinators as the very docile, ground dwelling, solitary, native cactus bee (Diadasia spp). Much additional work on native bees is needed to develop practical methods to: a) establish cactus bees on other plantations, b) manipulate the date of emergence to coincide with late/early flowering, c) develop protocols to safely apply pesticides to control insects such as cochineal without harming native bees, and d) develop other native insect pollinators early in the season (February/early March) when Opuntia flowers are available but no insect pollinators are available.