The June BBKA on-line update on Asian hornets was given by Richard Noel who is a Guernseyman with two hundred hives over in Brittany. Some 58 UK beekeepers took part.
The hornets arrived in 2022 and he says his hives were swamped. There was a prolonged period of hot and dry weather following a mild spring. There had been no spring trapping and later the traps filled up with no by-catch as they had all been eaten too including all the local wasps.
2023 was better and Richard trapped some 200 hornets in each of his apiaries from the end of February to mid May with the main activity from early March to the second week in April. By now there was a public initiative and the take-up of traps was good. They used the Vespa Catch trap which we have used on the IOM with 5.5mm holes to let out other insects. The best attractant was a mix of beer, white wine and fruit juice. Trappit costs €21 a litre in France.
He reported that other well promoted traps, including the Swiss one that we are going to buy, were not effective in the spring when the number of hornets around is low since there was not enough attractant in them. All traps are effective in late summer when there are more hornets about.
The current situation in Jersey shows they have trapped 2900 queens and destroyed 188 nests already this year. There are 819 public traps so spring trapping is effective if you have enough traps. Jersey is 45 square miles, our Island is 227, even if half of that is upland that still leaves an area some three times as big as Jersey to cover. 2400 traps??
To counter the invasion Richard consolidated his apiaries as hornet colonies seem fairly evenly spaced. He described other countermeasures like Nicot entrances which have a series of shutters to restrict access as far down as 5.5mm holes. Open mesh muzzles in front of the entrance seem to work but electric harps cost €300 each and you need two or three per apiary as well as a power source or solar panels. There is a drowning trap below the harp which needs to be kept topped up. He caught thousands of hornets in a Jabeprode trap which is a plastic box with two conical entrances with specially designed holes to free bycatch. There is a mesh below the entrances above the liquid bait.
He also noted that for every nest destroyed there would be three of four more in the vicinity only observed when the leaves came off the trees.
Dissection of autumn hornets showed that the queens had abdomens full of fat. He surmised that as soon as they were fed up that they would fly off and immediately hibernate so he questioned the efficacy of trying to catch them before the following spring.
The talk will be available on the members hub on the BBKA website shortly. Once in, click on Yellow legged Asian hornet and then YLAH Coordinator discussion forums.
