A strategy to prevent oriental hornets from destroying Maltese beehives is set to include traps to cull some of the plentiful population.
In a circular distributed to local beekeepers, baited traps set on active beehives are planned to be used to lure the hornets away from the bees and into the traps, where they are eventually expected to die off.
Last October, apiarists told Times of Malta they estimated that some 70 per cent of local beehives had been decimated by oriental hornets, with negative implications for local honey production and the agricultural sector at large.
Beekeepers described situations in which their hives were totally decimated by the hornets, with apiarists unable to intervene without being swarmed as the hornets attacked and killed their bees.
According to the circular, in collaboration with the Agricultural Ministry, registered beekeepers will be eligible for aid to construct hornet traps to prevent widespread bee loss.
Expected to run between February and May, the traps feature mesh caging wrapped around a wooden frame, with a cone to snare food as bait.
The cage will feature a one-way entry construction and will be topped with a grid-shaped lid with slats wide enough to allow bees to exit but not the larger-sized hornets.
Every queen we manage to catch means one less nest and, therefore, hundreds fewer hornets to deal with in the future
The circular suggests making one trap for every five hives and placing each trap on an active hive. Protein-based lures, such as meat or fish, particularly salmon, should be used and placed on a plate or something that creates a barrier between the food and the hive.
“Every queen we manage to catch means one less nest and, therefore, hundreds fewer hornets to deal with in the future,” the circular said.
The circular warns that the hornets’ venom is toxic and could be fatal if stung by one queen or five to 10 workers. Because of their tendency to prey on bees and eat garbage, studies show that the hornets can also be carriers of disease, so minimal contact with both people and bees is advised.
As every colony is capable of multiplying itself 30 times in the course of a year, the circular says, the most effective form of controlling the population is to target queen hornets in spring and autumn and eliminate nests during the summer.
However, it warns against killing too many hornets at a time or squashing hornets to kill them, as these emit pheromones which attract other hornets.
The traps should be effective as the hornets require movement to breathe and an inability to move for long periods of time will cause them to suffocate.