Mohammedi Arezki

Algeria has two distinct, geographical honey bee races: the tellienne bee, which gets its name from the Tel mountain range that stretches from Tunisia to Morocco, and the Saharan bee which native ground is situated at the Algerian-Moroccan border. In between them lies a large desertic steppe that acts as a geographical barrier, impossible for either bee to trespass. However, Tellienne beekeepers from the North seasonally transport their hives to the southwest of Algeria to produce honey, which puts the Saharan bees at risk. It creates genetic pollution, and the third generation hybrids that I have in my labs are particularly aggressive. I always say that the Saharan bee is the bee of the future: It can thrive in very hot climes, is incredibly docile, and produces much larger quantities of honey than the tellienne bee. But to be honest we still have much to discover regarding the Saharan bee, on a physiological and behavioral level; it remains very much a mystery.

I made my first observation in 2000, and reported that chemicals were the first risk factor for the Saharan bee. Back then, a locust invasion of epic proportion was stopped in its tracks by aerial spraying of large amounts of insecticides. Of course, many bees died in the process. Today, however, I have completely revised the hierarchy of risk factors. I have identified the tellienne as the main danger of the Saharan bee. Tellienne bees create many swarms in the wild, and produce many more bees than the Saharan bee. Which means that there will be infinitely more tellienne drones than Saharan drones to mate with a Saharan queen bee, which pollutes the genetic quality of that bee. There are other risk factors that endanger the Saharan bee, but of lesser importance, such as the bee-eater, a bird which primarily attacks the queen when she exits the hive to mate, and drones.

In our University grounds, we have 36 Varroa-resistant tellienne colonies that haven’t been treated at all since 2006. When I started this experiment back then, I had 250 hives. Year after year, most of them died because of the parasitic Varroa mite, which was very disheartening. But 36 colonies have developed resistance, and survive without any chemical help. If you don’t treat a colony that is sensitive to Varroa, it will die within three years on average. Now, as part of PLANT-B, I want to understand what these mechanisms of resistance are. How do the bees survive? Is it a physiological process, or is it a question of behavior? We thought for a long time that Varroa resistant bees mutilated Varroa mites while grooming and getting rid of them. But it turns out that they don’t, which is what we have explored in a recently published paper. I work with Yves le Conte to find out whether the Varroa resistant pupas emit a pheromone that sterilizes Varroa from inside the cell. If that’s the case, it would be completely groundbreaking.

It is crucial to understand these mechanisms of resistance, and find out whether they are replicable so that all of Algeria could benefit from it. Ideally, down the line, beekeepers would be able to produce their own resistant queens, because if they are all sourced in our labs, this would inevitably impoverish their genetic diversity. Of course, we cannot ask beekeepers whose livelihood depends on honey production to stop chemically treating their hives to find out whether they have resistant colonies: this would be too high a price to pay.

COVID has been an issue for all lab-related work. I had to ask for a special authorization so that my PhD student could go to the lab. My other student, who works on the Saharan bee, has been doing morphometry work with a magnifying glass from home. I had the presence of mind to move all 36 colonies near my house before the lockdown started, so that I could keep an eye on them. Of course, none of us has been able to travel to Ain Sefra, but we have an association there that kept working. So, all in all, it hasn’t been the best conditions, but we have managed somehow.