FLOWER CONSTANCY OF HONEYBEES AND ITS IMPORTANCE DURING PEAR POLLINATION

Detailed studies were made on the behavior of honeybees visiting the flowers of 13 pear cultivars in 1996. Overwhelming majority of them were pollen gatherers (95.6 per cent) deliberately scrabbling for pear pollen.
Proportion of pure nectar gatherers was as low as some 3.7 per cent and no more than 0.7 per cent of honeybees performed mixed behavior.
Pollen gatherers are usually regarded to be more effective pollinating agents than bees with another type of behavior.
Their efficiency, however, greatly depends on their flower constancy on blooming pear trees.
Therefore pollen loads of several dozens of bees were analyzed.
This showed that fidelity (proportion of pure loads plus mixed ones with less than 2 % contamination) was as high as 88–90 per cent, higher than for another fruit species in another studies.

High fidelity of honeybee foragers towards pear flowers is of great practical importance in pear growing because honeybees can be much more important and more effective pollinating agents of pear than generally believed.
Fidelity of pollen gatherers for pear pollen seems to be high even in the presence of competitor weed species in bloom.
This can decrease the competing effect of dandelion (Taraxacum officinale) and Stelleria media that are known to be of very strong effect to honeybee visits against flowering fruit trees.

Though as a source of nectar pear is not very attractive to honeybees, it is very attractive to them as a pollen source even when there are a great number of foragers present gathering great amount of pollen in a short time.
Pollen production seems to be abundant enough to attract a great number of honeybees and provide enough pollen to them visiting the pear trees in bloom.

For this reason it is worth to take this advantage and move honeybee colonies to pear orchards for supplementary pollination because they probably would not be influenced very much by the competing effect of the blooming weed flora, of blooming fruit trees or of another crops blooming simultaneously (except winter rape or of other related cruciferous crops). This is an exceptionally favorable condition that is not typical to another temperate zone fruit trees all.

VII International Symposium on Pear Growing

P. Benedek, J. Ruff

https://doi.org/10.17660/ActaHortic.1998.475.50