In Killingan coppice today I started to look for orange-tip butterfly eggs on the stand of lady's smock (Cardamine pratensis).
It was almost too easy. On the first plant I looked at there was a solitary characteristically shaped orange egg carefully placed beneath a flower stalk (see picture below near centre). They are usually put on their own like as though the mother knows that her caterpillars will have strong cannibalistic tendencies .
With a good deal of luck this will have turned into a butterfly by next May. Below is a female of the species.