Simon Colmer / Green-veined White butterfly egg (Pieris napi) above, Orange-tip butterfly egg (Anthocharis cardamines) below, on Garlic mustard (Alliaria petiolata) Sussex, UK. June.

Wild Wonders of Europe / Biancarelli / Snail on Garlic mustard (Alliaria petiolata) leaves, Hallerbos, Belgium, April 2009. WWE OUTDOOR EXHIBITION. NOT AVAILABLE FOR GREETING CARDS OR CALENDARS

Nigel Cattlin / Mealy cabbage aphid (Brevicoryne brassicae) infestation on secondary host plant Hedge mustard (Alliaria petiolata). Berkshire, England, UK. June.

Alex Hyde / Orange tip butterfly (Anthocharis cardamines) chrysalis on Garlic mustard (Alliaria petiolata) Peak District National Park, Derbyshire, UK, August.

Kim Taylor / Orange tip Butterfly (Anthocharis cardamines) egg on Garlic Mustard (Alliaria petiolata) flower stalk. Surrey, England, UK, May. Digitally enhanced.

Rod Williams / Garlicmustard (Alliaria petiolata) Brockley Cemetery, Lewisham, London. April.

Will Watson / Large white butterfly (Pieris brassicae) caterpillar on Garlic mustard (Allaria petiolata), Cambridgeshire, England, UK, August.

MYN / Niall Benvie / Orange tip butterfly (Anthocharis cardamines) on Garlic mustard (Alliaria petiolata), Burgundy, France. April.

MYN / Niall Benvie / Orange tip butterfly (Anthocharis cardamines) on Garlic mustard (Alliaria petiolata), Burgundy, France. April.

Alex Hyde / Chrysalis of Orange Tip Butterfly (Anthocharis cardamines) on Garlic Mustard (Alliaria petiolata). The orange wing tips clearly visible through the chrysalis show that this is a male just about to eme...

Alex Hyde / Chrysalis of Orange Tip Butterfly (Anthocharis cardamines) on Garlic Mustard (Alliaria petiolata) against black background in mobile field studio, The orange wing tips clearly visible through the chry...

Alex Hyde / Chrysalis of Orange Tip Butterfly (Anthocharis cardamines) on Garlic Mustard (Alliaria petiolata). The orange wing tips clearly visible through the chrysalis show that this is a male just about to eme...