Stories GM plants no problem for the honey industry

Honeybees play an important role as pollinators for many plants. They fly from flower to flower, collecting nectar and pollen without paying any attention to field boundaries. If genetically modified Bt maize is grown, bees will certainly come into contact with the GM plants. Is there any impact on the honey production as a result? Scientists in Bavaria (Germany) have been investigating this question in a number of experiments.

Responsible for the study was the Bavarian “Landesanstalt für Weinbau und Gartenbau (LWG), which undertook the experiments together with other local institutions. The results were published in 2005 and included the analysis of honey and pollen collected by bees in closer proximity to GM maize cultivations.

Bees are important pollinators for many plants

To learn about the influence of GM cultivations on honey production, separate bee colonies were positioned first immediately next to GM maize, secondly next to conventional maize and thirdly in meadow areas at a distance of 700 metres from the GM maize field. The honey was collected and analysed employing molecular biological methods. In 17 of the 36 samples, scientists detected maize although no genetically modified maize could be found. This indicates that intake of GM maize into the honey was so low as to be below analytical detection limits.

Pollen loads
Bees also collect pollen, which they transport in the form of small balls, known as pollen loads, on their hind legs. In the hive, they scrape this pollen off and store it in cells. The analysis of such pollen loads revealed that all samples – with one exception – contained maize pollen and that traces of GM maize could be identified. Two bee colonies had pollen loads with a GM maize level of approximately 5 percent, whereas the majority remained below the threshold of 0.9 percent and therefore also would remain exempt from labelling requirements when used in pollen products. These products may be used in nutritional supplements with a high content of proteins and vitamins.

Spring honey
Spring honey is harvested before maize flowering takes place, and therefore only may contain leftovers from pollen collected in the previous year. The researchers detected in only two of such honeys traces of maize pollen. These traces were, however, too small to be analysed for genetically modified maize.

The entry of GM maize into honey can be eliminated almost fully if bee colonies are not close to the GM field.

Maize pollen on other bee plants The experiments also confirmed that maize pollen is transported by wind onto other plants that are attractive for honeybees and are “visited” often. The amount of maize pollen proved to be higher at closer proximity to the maize field than at greater distances. However, traces of GM maize could not be detected in this pollen. The scientists also were unable to detect GM maize in the collected honey. This was in line with results from the previous year, in which GM maize was found in the honey at extremely low amounts despite the fact that pollen distribution had been significantly higher.

The researchers demonstrated that the entry chance of GM maize into honey can be eliminated almost fully if the bee colonies are not in close proximity to the GM field. The experiments confirmed that bees are not attenuated or harmed by approved genetically modified maize varieties. The scientists thereby concluded that the cultivation of Bt-plants does not affect the beekeeping industry.

See also on GMO-Compass:

• GMO Labelling: Guidelines - These Products Do Not Require Labelling