Berry unexpected: Nocturnal pollination of lowbush blueberry

Abstract

Cutler, C. G., Reeh, K. W., Sproule, J. M. and Ramanaidu, K. 2012. Berry unexpected: Nocturnal pollination of lowbush blueberry. Can. J. Plant Sci. 92: 707–711. Lowbush blueberry, Vaccinium angustifolium, is an economically important crop of eastern North America that is critically dependent on insect-mediated cross-pollination for successful fruit set and high yields. It is generally assumed that bees are responsible for the vast majority of lowbush blueberry pollination, and producers usually augment the natural pollination force with managed bees. Little is known, however, of the potential role of nocturnal pollinators in lowbush blueberry production. We conducted a field experiment where patches of blooming blueberry were exposed to flying insects 24 h a day, only during the day (sunrise to sunset), only at night (sunset to sunrise), or 0 h a day. We found that significant fruit set occurred on blueberry stems that were exposed only at night, although it was higher on stems exposed during the day or 24 h a day. However, ripe fruit produced on stems exposed only at night weighed just as much as those exposed 24 h. Captures with Malaise traps activated only at night consisted mainly of several families of Lepidoptera and Diptera, although we do not know if these taxa pollinated blueberries. We conclude that nocturnal pollination may contribute significantly to lowbush blueberry fruit set.