Warning coloration in sawfly Athalia rosae larva and concealing coloration in butterfly Pieris rapae larva feeding on similar plants evolved through individual selection

Green larvae of the butterflyPieris rapae and black larvae of the sawflyAthalia rosae feed on green leaves of the same cruciferous plants. To demonstrate thatP. rapae has concealing coloration and thatA. rosae has warning coloration, the larvae of the two species were supplied to naive chicksGallus gallus on white, green or black backgrounds.P. rapae larvae were palatable and their green body color acted as a concealing coloration. On the other hand,A. rosae larvae were unpalatable and their black body color acted as a warning coloration.