ORIGINAL PAPER Intra-specific variation of behavioral signals in suppressing plant defenses in the green peach aphid Myzus persicae, feeding on the resistant wild peach Prunus davidiana M. A. Cabrera-Brandt • J. A. Verdugo • C. C. Ramı ´rez • J. P. Lacroze • M. H. Sauge • C. C. Figueroa Received: 14 April 2014 / Accepted: 20 July 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract The green peach aphid, Myzus persicae (Sulzer), is a generalist insect herbivore capable of using a wide range of cultivated plants and weeds. In this laboratory study, we examined the inter-clonal variation in M. persicae’s ability to exploit the wild peach Prunus davidiana, a source of genetic resistance to aphids used by peach breeding programs. An initial screening of a set of sexually reproducing clones col- lected from commercial orchards planted with susceptible varieties found significant genetic variation in aphid survival on P. davidiana. Comparison of two clones (Fr2 and Fr12) found marked differences in colony sizes achieved. A detailed analysis of probing and feeding behavior showed that the clone exhibiting the highest performance on P. davidiana (Fr2) initiated probing earlier than the lower performing clone (Fr12). Periods of non-probing were also significantly shorter for this clone. Finally, Fr2 produced more and longer events of watery saliva injection into sieve elements. We discuss these results in terms of host plant adaptation by aphids and their capacity to overcome plant-resistance genes. Keywords Myzus persicae Á Prunus davidiana Á Prunus persica Á Feeding behavior Á Performance Á Interclonal variation Key message Plant resistance to pest attack is not an all-or-nothing interaction, but depends on the genetic variability in plant and insect defenses. Colony performance and feeding behavior were studied in distinct genotypes of the green peach aphid reared on a susceptible peach cultivar and the resistant wild related species Prunus davidiana. Aphids showed interclonal variation in the performance which is related to salivation into the sieve elements. The results are discussed in terms of aphid adaptation to host plant resis- tance and its implication for peach breeding programs. Communicated by M. Jonsson. Electronic supplementary material The online version of this article (doi:10.1007/s10340-014-0614-2) contains supplementary material, which is available to authorized users. M. A. Cabrera-Brandt Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile M. A. Cabrera-Brandt Á C. C. Ramı ´rez Á C. C. Figueroa (&) Millennium Nucleus Centre in Molecular Ecology and Evolutionary Applications in the Agroecosystems, Universidad de Talca, 2 Norte 685, Talca, Chile e-mail: alfigueroa@utalca.cl J. A. Verdugo Centro Regional de Innovacio ´n Hortofrutı ´cola de Valparaı ´so (Ceres), Pontificia Universidad Cato ´lica de Valparaı ´so, Av. San Francisco s/n La Palma, Quillota, Chile C. C. Ramı ´rez Á C. C. Figueroa Laboratorio de Interacciones Insecto-Planta, Instituto de Ciencias Biolo ´gicas, Universidad de Talca, 2 Norte 685, Talca, Chile J. P. Lacroze Á M. H. Sauge Institut National de la Recherche Agronomique, UR 1115 Plantes et Syste `mes de Culture Horticoles, Domaine Saint Paul, 228 Route de l’Ae ´rodrome, Avignon, France 123 J Pest Sci DOI 10.1007/s10340-014-0614-2