Fig. 2

Photographs of plants and insects in the study field. a Leaf holes made by flea beetles (arrows), b a striped flea beetle Phyllotreta striolata, c a turnip flea beetle Phyllotreta atra, d mustard aphids Lipaphis erysimi, e a larva of the turnip sawfly Athalia rosae, f a newly hatched larva of the cabbage butterfly Pieris rapae, g a larva of the diamond back moth Plutella xylostella, h a western flower thrips Frankliniella occidentalis, i the field site in Zurich, Switzerland, and j the field site in Otsu, Japan