Chemical basis for inter-colonial aggression in the stingless bee Scaptotrigona bipunctata (Hymenoptera: Apidae) - Jungnickel, Harald; Costa, A. J. S. da; Tentschert, J.; Patricio, Eda Flavia L. R. A.; Imperatriz-Fonseca, Vera Lucia; Drijfhout, F.; Morgan, E D (Journal of Insect Physiology, 2004)