Wren, Nicotine, Neonics and Viruses

This wren was catching the light in the disused aluminium block of glasshouses this morning. When I looked at the image on screen I noticed that it included a Campbell's nicotine shreds tin. Growers used to burn these shreds to kill insect and invertebrate pests. MrQ remembers, in particular, using them to kill a plague of millipedes which was chomping through his cucumber stems.

The modern neonicotinoids work as acetylcholine receptor agonists, in the same way that nicotine does. They have been banned by the EU as they adversely affect bees, though they have a low mammalian toxicity. This ban has meant that oil seed rape cannot be easily be grown now as these chemicals were used to dress the seed to prevent flea beetle infestation. Last time I photographed an oil seed rape crop a few years ago it was swarming with beetles. Growers are experimenting with companion planting. Yellow mustard looks promising, it is not certain whether it masks the smell of the rape making it difficult for the beetles to locate or maybe the beetles prefer its taste to that of rape. Countryfile's Adam Henson uses buckwheat and dresses the crop with human waste to confuse the beetles.

Talk in the Press about the possible re-introduction of neonicitinoids after Brexit is not the full story. Evidently there is a virus spread by aphids sweeping through and decimating sugar beet crops. As I understand it the sugar beet growers applied for a special dispensation to use neonics in a strictly controlled bee-friendly way to deal with the crisis and were refused. I think they're hoping post Brexit their application will be reconsidered.

We experienced a virus crisis when we were producing ornamentals. The Western Flower Thrip, a native of North America, arrived here. It was a vector for Tomato Spotted Wilt Virus. Busy Lizzies were particularly susceptible. I think this might be one of the reasons that growers stopped producing these popular plants on the vast scale that was usual in the eighties and nineties.

Damned viruses.