Beware of bycatch when trapping Asian hornets

It is vitally important to release these native insects as the offspring they produce will play an important part in controlling a wide range of insects harmful to human food production

A COUPLE of weeks ago I wrote about a sparrowhawk that had been found dead in a property in St Brelade and I pondered on the possible cause of its demise.

A few days later the frozen bird was taken into the JSPCA and a post mortem carried out to determine the cause of death and a tumour was found in the bird’s crop.

This growth had restricted feeding and to a certain extent breathing so that the bird’s ability to hunt and eat became marginal leading to its death.

These hawks rely on stealth and speed to catch their prey and the slightest injury affecting their physical performance can be life threatening.

Last year I was told of someone who had installed a number of successfully occupied artificial swallow nests on their property and was bemoaning the fact that a sparrowhawk had been consistently taking birds as they returned to their nest sites and wondering how to be rid of the troublesome hawk.

It was pointed out to the site owner that apart from it being illegal to kill wild birds it was not the swallows that were on the red list but the hawk.

With the temperatures increasing, albeit for a short period of time, and the winds forecast to come from the east I spent time early in the week setting out Asian hornet traps along the coast from La Saie to Fauvic.

This now means that the traps have to be checked every day because it is not just the hornet that will visit them. Queen wasps are also emerging from their winter hibernation and need to replenish their energy stores and are drawn to the traps.

It is vitally important to release these native insects as the offspring they produce will play an important part in controlling a wide range of insects harmful to human food production. After all, the aim is to prevent the invasive hornet from decimating our insect population and not adding to this loss by the death of the bycatch found in the traps.

Another insect that occasionally turns up in the traps is the moth and uncapping a trap this first week’s moth capture turned out to be a herald moth (Scoliopteryx libatrix). This is a common over-wintering species and, unsurprisingly, it is attracted to light and sweet food sources. The trap it was in is close to a house and has willow trees near by which are one of the food sources for the moth’s larvae.

The scalloping on the wings and russet brown colouration provides it with very effective camouflage when at rest and when it was released it flew straight to the nearest tree for cover.

Midweek I received a call from a fellow beekeeper to say that he had caught an Asian hornet which had been found by his wife flying around in the bedroom. It had been caught using a butterfly net and so was an initial challenge to remove and place into a container.

This one will be an over-wintering queen and likely to have spent the cold months tucked away in the room somewhere safe before being woken by the increasing daytime temperatures. Late on in the last year I collected a queen found hibernating in a flowerpot on Rue Saint Julien shortly after receiving a call of a sighting of one in a roof space at Rosewood House across the road from St Saviour’s Hospital. This week’s hornet was recorded between the hospital and Houge Bie so it is likely that a nest went undetected somewhere in the middle of these sightings, so traps have been deployed in the area just in case there are other emerging queens from that lost nest.

On to honeybees now for with ever-increasing numbers of plants coming into flower, increasing temperatures and daylight our bee colonies are expanding rapidly.

It is time to check the condition of the brood frames within the hives and if need be, replace old and poor waxes to reduce the risk of disease and increase brood capacity. Though some of our hives still have solid floors we are slowly replacing these for open mesh floors.

During the course of a year debris such as old wax, bee hair, varroa mites, nectar and general detritus cascade down and build up on solid floors again giving rise to disease potential.

Open mesh floors mean that this debris falls out onto the ground, reduces infection risk and ventilates the hive so reducing moisture that can build up, especially during the winter months.

It seems counterproductive to do this given that it is vital for the bees to be able to maintain a core temperature around the brood of 36 degrees at all times, but they are more than capable of achieving this and there is little doubt that they fair better on this system rather than with the old method of solid floors.

An observation we made this week when out and about was how well some of the hawthorn hedging plants are doing, especially the ones that have not had protection sleeves fitted to them as they have growth forming much lower down the stem and appear stronger.

Given that the Island’s rodent and rabbit population seems to be doing well there is no evidence that they have been eating the bark of these unprotected plants and so reducing the number growing to fruition. The question then is are these guards really necessary given the risk of site contamination these sleeves cause long-term?

We took time off on Sunday to join a Botany group wondering the edge of Grouville Golf Course and found a host of interesting plants and a long-standing car park tree that I had failed to notice before. It is a wych elm (Ulmus glabra) a native species once common before the arrival of Dutch elm disease so it is hoped that this majestic tree will live long and prosper.

It is self-pollinating, flowers in early spring and is now festooned with winged fruits known as samaras that bare a single seed in the centre and when ripe the seeds are dispersed by the wind.

When it comes to dune plants small and perfectly formed is the order of the day with many so small that a hand lens is needed to appreciate their beauty. One such gem is the perennial sand crocus (Romulea columnae) that can be found in among short open grasses close to the sea wall and grows no taller than 10cm. The flowers are small, rarely exceeding 12mm across, and are pale purple with a deeper purple vein along the petal centres and bright yellow anthers.

Among the many others was the tall ramping fumitory, (Fumaria bastardi) another sandy grassland specialist. It has small, flat broad-shaped leaves and long purple pink flowers with darker coloured tips. Though rated as endemic in the UK it is not common and considered under threat.

The highlight for me was spotting three male green lizards (Lacerta bilneata) sunbathing in a small patch of vegetation only meters away from the car park despite the continuous footfall of people heading for the ice cream van.

By Bob Tompkins

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