ABSTRACT The effectiveness of pollination of tomatoes by the bumble bee Bombus vosnesenskii
Radoszkowski in greenhouses was determined between May and August 1991 by
measuring fruit size and seed content. Bumble bee pollination was compared with no pollination,
manual pollination, and manual plus bumble bee pollination. Bumble bee-pollinated ßowers
produced larger fruit than non-bumble bee-pollinated ßowers. Fruit shape was not affected by
bumble bee pollination. Our results show that B. vosnesenskii is an effective pollinator of
tomatoes in greenhouses.