Reader Letter: Where have all the butterflies gone in Norwich?

Am I only person in Norwich who up to writing this letter (July 1) has not seen a single butterfly in my garden this year, not even a cabbage white, which for years have been by far the most common species who visit regularly. My terraced house small garden looks like something out of the past with the ground filled with flowers, roses, fruit bushes and self-seeding wild flowers and with short open fencing, unlike today's standard garden with six foot plus fencing and the ground area covered with slabs. The butterfly's absence has for some reason caused a marked increase in the bee population which now is made up of all types in colour and size. Are bees now finding it safer to live in the city rather than the countrside? I leave my back kitchen door open most summer days and stray bees are removed by letting them rest on my finger, and I have never once been stung doing this.