Holes in plastic are best made with a nail or such like, heated using a blowlamp in a well-ventilated area.
Holes can be accurately sized using drills that come as standard e.g. 5.5mm, 7mm, 8.5mm etc.
Trap (bottle) sections can be held together using a long pin made from a wire coat hanger.
In my view, the best bottles to use are water bottles from Aldi as they are strong and fit together well. The worst are Coke bottles because of their irregular shape.
If the trap becomes full, detach the bait holder, put the trap in a plastic bag and either put it in a freezer overnight, or into a honey warmer set to >50C, the equivalent of the bees’ heat balling, before emptying the contents into a bag, crushing them and disposing of them.
It is recommended that you pierce some holes in the bottom of the bait holder section to avoid condensation build-up, which reduces solar gain. The holes also aid natural air convection up the trap that in turn enhances odour diffusion.
Tests in January on cold sunny days have confirmed the added value of putting the bait into a small tin (painted matt black as shown in the photo here). The temperature of the bait quickly gained >16°C over the outside temperature; the warmer the bait, the better the odour diffusion.
This is an important point: Do not rinse out the trapping chambers when emptying the traps as the hornet’s pheromone is an attractant to other hornets.
Spring trapping
As Spring turns to Summer