Aphids (Hemiptera: Aphididae) are ancient insects, whose fossils go back to the Triassic, about 220-210 million years (Grimaldi and Engel 2005). To date, they are present in most of the world’s biomes, including the tropics and subarctic regions, where they infest a huge range of plants (Loxdale 2009) causing several damages due not only to their direct parasitic action against crops, but also because they are active vectors of numerous crop viruses (Blackman and Eastop 2000, 2006, 2007; van Emden and Harrington 2007).