We have a lot of pigeons at the allotment so netting berries, brassicas and peas is essential. I was very pleased with my netting efforts which resulted in tall, healthy plants… and complacency on my part regarding other pests. I didn’t notice the stealthy manoeuvres of the cabbage white butterflies and have now discovered several leaves on my brussels peppered with these squatters. Lets hope they don’t notice the sprout buds on the stems before I get a chance to remove them all.
Cabbage white caterpillars like munching on brassica leaves because the high concentrations of sinigrin (mustard oil) they contain accumulates in the caterpillars body and deters predators from eating them. Cunning and with no help from the birds the only option is to remove them all by hand. Ewww, fortunately with the sprouts I can live without the leaves! And next year? 6mm net to prevent the butterflies from getting in and laying their eggs.
ps. the BBC website has a brilliant tool for identifying pests and diseases on plants