A scientific note on the use of stingless bees for commercial pollination in enclosures

Abstract

Stingless bees are considered to be very important pollinators in the tropics, and they are known to effectively pollinate at least 9 crops [1]. Nevertheless, they are seldomly used for commercial pollination. To our knowledge, only one study has been published using stingless bees for crop pollination [2]. In that study, Nannotrigona testaceicornis was used successfully to pollinate strawberries in a greenhouse in Japan. There are several advantages that might make stingless bees more suitable for the pollination of certain crops than the commonly used honeybee [1, 3]. The fact that they lack a functional sting makes them especially suitable for pollination in enclosures. In our study, we compared the pollinating activity between two species of sting-less bees and honeybees on the ornamental plant Salvia farinacea var. strata (Lamiaceae) in enclosures. S. farinacea is an ornamental herbaceous plant, with small (ca. 1 cm) purple and white flowers. It is commercially grown for seed export, usually in enclosures to ensure the production of pure seeds. Experiments were carried out at the seed company Flora Feliz, Cartago, Costa Rica (9° 43 51 N, 83° 54 51 W, altitude 1388 m). Flower visitors of S. farinacea were captured in an open-air patch of 40 plants in December 1995. Pollination experiments were conducted in four netted enclosures (6 ´ 3 ´ 3 m) in April 1996. Each enclosure contained 60 plants that were pollinated by one of the three bee species during one month, or were left without pollinators (control). The following bee species were used: Nannotrigona testaceicornis, Tetragonisca angustula, and Apis mellifera. N. testaceicornis is a small robust bee with a body length of 4.1 4.2 mm. Colonies contain a few thousand individuals and the species is quite common in the Neotropics. T. angustula is a small, slender bee with a body length of 4.4 4.7 mm. It is the most abundant stingless bee species in Costa Rica with a colony size up to 5,000 individuals. We used a 5-frame hive of Africanized A. mellifera with approximately 10,000 workers.