There are an estimated 100 trillions (!) bees in the world (the data range is quite broad, actually, for the difficulties in estimating the number of wild bees, domesticated ones are in the range of 2-5 trillions). This is a mind boggling number, and quite frankly it would remain so -at least for me- whether there are just a few trillions or a 100 trillions bees.
Bees are crucial to our survival since they are an integral element of the food chain, serving as pollinators. Unfortunately pollution is affecting bees all over the world, in some areas researchers have seen a die-out of up to 70% of bees colonies. Another proof of the damage of human induced pollution was given in recent months by the lock-down. It decreased the air pollution and bees have been gaining in strength, producing more honey!
In this framework the news that researchers have been able to use drones for pollination becomes interesting. There have been several attempts in the past to find ways for artificial pollination but so far they failed, in most cases because the way used to deposit the pollen on the pistil damaged the flower. Farmers in the northern part of Japan use manual pollination for pears and apple trees (because it is too cold for bees to do the job): they use a sort of feather to pick up the pollen and deliver it to other flowers but the result is far from optimal (it turns out bees are much better!). Using a feather requires spreading 1800 mg of pollen on each flower, that is quite a lot!
Researchers at the Japan Advanced Institute of Science and Technology have experimented with a toy-drone that uses soap bubble to deliver the pollen. The experiment showed that the approach worked: the three trees that were pollinated by the drone produced the same amount of fruits of trees pollinated naturally. For the pollination 0.06mg of pollen per flower was sufficient, that is 30,000 times less than by using a feather. The problem with pollinating with a drone is that the flow of air created by the propeller makes it impossible to target a specific flower making this approach unsuitable where flowers are far apart from one another, An alternative would be to use robots moving on the ground with an image recognition system able to detect flowers and with a computer aiming the bubbles to them. This can work with some types of plants that have flowers close to the ground but it is impractical for apple trees where you need to pollinate flowers on top of the tree.
Interestingly, drones are already used for pollination (watch the clip) but in this case they are not carrying the pollen, rather the downdraft of air generated by the propellers shakes the flower and move the pollen from one flower to another resulting in pollination. This seems to work well with strawberry plant …
I found interesting these researchers for the amount of converging technology being used but, as many scientists I remain skeptical: bees are by far the best pollinators around and it is much better to focus our efforts in preserving them!