Pollination is a complex process. It’s not as easy as an insect simply visiting a flower.
This is important to remember when talking about which species are the ‘best’ or ‘most important’ pollinators. Simply observing an animal visiting a flower is not, on its own, evidence that the animal is pollinating the flower.
Many insects (and other animals) visit flowers, to feed on pollen, nectar or other flower parts. Many of these interactions result in pollination…although some visitors are better pollinators than others. Some of these visitors commit floral larceny – they are robbers or thieves (there’s a difference!) of either pollen or nectar, and they leave without pollinating. Some might even damage flower parts so much that they indirectly affect the flower’s capacity to be pollinated by other visitors.
To know for sure that an insect is pollinating a particular flower, we first need to know what kind of reproductive system that flower has. Is it male, female or bisexual (containing both male and female parts)? Can it self-pollinate, or does it need to be outcrossed to another flower or plant of the same species? Once we know this, we then need to watch the behaviour of the insect that visits that flower. Does the insect visit one flower and fly away, or many flowers in a row? Does it move between plants? Does it actually touch the reproductive parts of the flower when it visits each flower? Continue reading