Interesting video, Trojan. It's a good (or maybe bad?) example of the dangers of introducing non-native organisms (plants as well as animals) from one country to another. Without their natural predators, the introduced species can too easily take over.
A less dramatic but still worrying effect of introductions is genetic change due to cross breeding between native and introduced species or strains. To digress to plants, there is concern over hybridisation between our native British bluebell (
Hyacinthoides non-scripta) and the introduced Spanish bluebell (
H. hispanica). The resulting hybrid (
H x massartiana) has the potential to displace at least some of our native populations and there's some more information on it
here and
here. I've certainly seen hybrid as well as native bluebells on the Great Orme.
To return to bumblebees, as opposed to the "killer" honeybees, there are concerns about the escape of continental strains of buff tailed bumblebees (
Bombus terrestris), which have been introduced to commercial glasshouses for pollination of tomatoes, as these bees could potentially breed with our native strains. (Pollination of some plants, such as tomatoes, requires "buzz pollination" which only bumblebees can do. In Australia workers in tomato glasshouses apparently use vibrators on the tomato flowers to simulate the effect of "buzz pollination"!)
You may have heard in the news about the appearance and spread of a "new" bumblebee species in the UK.
Bombus hypnorum, the tree bumblebee, arrived from the continent in about 2001, apparently under its own steam. Starting in the south east, it's been spreading northwards and westwards and there have recently been a couple of reports of it in North Wales. It tends to nest in trees but will happily move into bird boxes, while our endemic bumblebees generally nest below ground or at ground level. It's quite a distinctive bee, with a brown thorax, black abdomen and white tail, and it's too early to determine if it's having any affect on our native species. In this rather bad photo there are five male tree bumblebees buzzing about outside a nest in a yew tree in the East Midlands, waiting for the new queens to emerge. If disturbed at the nest, the worker bees (which can sting) may be quite defensive. Has anyone seen these in North Wales yet?