The new study by Fischer et al. which has just been published had such promise. But yet again, we see another opportunity for a realistic study which could shed some light on the debate into factors which affect bee colony health has been wasted.
The study objective was to show if certain neonicotinoid compounds may have sub-lethal effects on the homing flight behavior and homing success of individual honey bees.
The team was able to show various effects on individual bees but what does this actually mean for our pollinators in the field? Unfortunately, not a lot, as honey bees don’t live solitary lives, they live as a colony. That means that these results have little relation to the colony as a whole and the colony was not included in this study.
It is also worth bearing in mind that an excess of many things will make us ill or show some adverse effects. How many of us have drunk too much coffee and spent a long night unable to get to sleep or suffered after eating too much of a favorite food. So it was in this study where the treated bees were fed amounts of compound which would have been almost enough to cause half of them to die. This is way in excess of what they may find while foraging in the field under realistic conditions. Take one of the compounds tested, thiacloprid was reported as being fed to bees in this study at 12,500 ppb. But, according to German Bee Monitoring, carried out in the actual fields, the highest levels found in bee bread in the hive was around 200 ppb. This means that, in this navigation study, bees were exposed to thiacloprid at over 60 times more than has been reported to be taken up by bees in the field. So why test at such high amounts – could it be that this is the only way the researchers doing this study could actually see any adverse effects on navigation and homing success in honey bees?
Even then, what did they find? Did the treated bees all fly off forever and never come home? In actual fact, many of the bees did make it home to the colony – amazing considering the dose they were given. Some may have taken different flight routes to normal, some took shorter or longer times to get there but many of them did make it.
All the compounds tested have been used on a large scale on bee-attractive crops, such as oilseed rape, for many years and there have not been any reports of systematic losses or weakening of honey bee colonies near these crops during all this time.
Therefore, as is so often the case with studies over the past few years, these results show an effect but do not give a true representation of the real situation in the field. So now more research is needed at realistic field rates, under realistic conditions to see if there are any significant effects on the bees and the bee colony as a whole.
Isn’t it time that researchers took responsibility and carried out meaningful studies at realistic field rates, in the first place, that could help find solutions to the real factors affecting bees? How else will we ever know which factors truly are the ones we need to address to help protect our bees.