There's a world of difference between confirmed and reported sightings. Why would you expect the NBU to report suspected sightings?
There is definitely a need for alerts to be raised. The question is how to achieve this calmly and effectively. What is required is cool heads with a defined sense of purpose rather than an instalment of Keystone beeks!
I remain of the opinion that the best course of action is that all beekeepers set up wick based bait stations and monitor periodically. I would suggest that the level of monitoring should depend on level of risk. Monitoring is a function of the number of bait stations and the interval over which each bait station is observed which itself will be a function of the time of year.
Using a green, amber and red risk based system is a good idea based on distance from previously confirmed nest locations but I would suggest changing the proximities so that distances of more than 30 miles are considered green, between 30 and 10 miles are amber and anything less than 10 miles are considered red.
In green zones, I would suggest that beekeepers set just one wick based bait station preferrably at a location as close to a water source as possible that has woodland not too far away such that the scent of the bait station is carried towards the woodland. The bait station should be observed for a one hour spell once a fortnight up until the beginning of July. Thereafter, the bait station can be observed for a 20 minute spell once per fortnight.
In amber areas as for green areas plus I would suggest increasing the frequency of observations to weekly instead of fortnightly and I would suggest augmenting the use of bait stations with observation of naturally occuring flora, wood pulp sources and compost heaps (important hunting ground for vespines).
In red areas as per amber but I would suggest increasing the number of bait stations but would suggest setting the bait stations at linear intervals of 250m. By linear intervals, I mean along the edge of woodland (circa 50 to 100m away) such that the scent of the bait stations is carried into the woodland.
When setting bait stations, prevailing wind direction is important. Velutina is a preferred high level wet woodland nester. It is important therefore to carefully consider the direction of the scent plumes produced by the bait stations to maximise their draw. Linear orientation with perpendicular prevailing wind will maximise draw. Longitudinal orientation is simply a wasted deployment of bait stations.
I would caution against setting bait stations in close proximity to apiaries and what is more, I would strongly advise against setting bait stations such that their scent travels towards the hives. That is simply begging for trouble because it will only serve to draw any velutina to the hives instead of the bait stations.
Apiaries also need to be monitored as a separate draw. So placing bait stations at apiaries only serves to reduce the availability of observation points.
Monitoring at hives should also be risk based. In green areas carry on as usual. In amber areas inspect apiaries at least weekly observing hives for at least a 20 minute spell. In red areas, observe hives every third day and observe again for at least a 20 minute spell.
Finally in this instalment, don't forget to maintain the bait stations to keep them topped up. I would recommend adding maple syrup to the sugar mix. A good indicator of how well the bait station is working will be the presence of other insects but don't be surprised if your bait stations are ignored by other indigenous vespines during the hunting season. Queen wasps will exploit bait stations until they become nest bound. After that worker wasps generally won't come to sweet bait stations until their nests mature which usually won't be before the end of July. This is because vespine workers get all of their carbs from within their nests. Velutina workers on the other hand require supplementation which is why they will come to bait stations earlier than vespines.
There is one other bait that might be worth experimenting with and that is macerated grass with alcohol. I know this sounds wacky but one of the ways in which vespines find grazing insect prey is by detecting the smell of leaf damage caused by grazing insects. The bait requires grinding a handful of grass with a little cheap vodka and then diluting with water and using this in a wick bait station. I'm not recommending this as a substitute for sweet bait stations. Just a suggestion to experiment with. If the grass bait station attracts hunting wasps (including queens) it will be a good substitute for protein baits which go off and stink after a while.
