Cartoon by John Sadler www.johnsadlerillustration.com

• IAN Pett asked; What has happened to all the butterflies? (Letters, July 4). What is affecting butterfly numbers is a shortage of food plants for their caterpillars.

The red admiral, small tortoiseshell, peacock and comma butterflies all lay their eggs on stinging nettles, the food plant of their caterpillars.

No stinging nettles no familiar and favourite butterflies. Time to add nettles to the wildlife area must-have? They like sun and a fertile soil.

CHRIS HEATH
Kentish Town City Farm