Volatiles mediate host-selection in the corn hoppers Dalbulus maidis (Hemiptera: Cicadellidae) and Peregrinus maidis (Hemiptera: Delphacidae) M.V. Coll Aráoz 1,2 * , V.G. Jacobi 3,4 , P.C. Fernandez 4,5 , E. Luft Albarracin 1 , E.G. Virla 1,6 , J.G. Hill 1 and C.A.N. Catalán 7 1 PROIMI-Biotecnología, CONICET, Av. Belgrano y Pje. Caseros, S.M. de Tucumán, Tucumán, Argentina: 2 Facultad de Ciencias Naturales e IML, UNT, Miguel Lillo 205, San Miguel de Tucumán, Argentina: 3 INBA-CONICET, Instituto de Investigaciones en Biociencias Agrícolas y Ambientales, Buenos Aires, Argentina: 4 Facultad de Agronomía, Cátedras de Química de Biomoléculas y Genética, UBA, Av. San Martín 4453, CABA, Argentina: 5 CONICET-INTA, EEA Delta del Paraná, Paraná de las Palmas y Cl Comas, Campana, Argentina: 6 Instituto de Entomología, FM Lillo, Miguel Lillo 251, San Miguel de Tucumán, Argentina: 7 INQUINOA-CONICET, Instituto de Química Orgánica, Facultad de Bioquímica Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 491, San Miguel de Tucumán, Argentina Abstract Volatile organic compounds (VOCs) released by plants are generally involved in host recognition and host selection for many phytophagous insects. However, for leafhoppers and planthoppers, host recognition is mainly thought to involve a photo- tactic response, but it is not clear if a host plant could be selected based on the volatile cues it emits. In this study we evaluated olfactory responses in dual choice tests of two Hemiptera species, Dalbulus maidis (De Long) (Cicadellidae) and Peregrinus mai- dis (Ashmead) (Delphacidae), vectors of maize-stunting diseases, to three maize (Zea mays L.) germplasms, a temperate and a tropical hybrid and a landrace. VOCs emit- ted by the germplasms were collected and identified using gas chromatography- mass spectrometry. The temperate hybrid released significantly more VOCs than the tropical hybrid and the landrace, and its volatile profile was dominated by (±)-li- nalool. D. maidis preferred odours emitted from the temperate hybrid, whereas P. maidis preferred odours from the tropical hybrid and the landrace over the temper- ate one. In order to test if linalool plays a role in the behavioural responses, we as- sayed this compound in combination with the tropical hybrid, to provide other contextual olfactory cues. D. maidis was attracted to the tropical hybrid plus a 0.0001% linalool solution, indicating that this compound could be part of a blend of attractants. Whereas addition of linalool resulted in a slight, though not significant, reduction in host VOC attractiveness for P. maidis. Both hopper species responded to olfactory cues in the absence of supplementary visual cues. *Author for correspondence Phone: +54 381 434 4888 Fax: +54 381 434 4887 E-mail: victoriacoll@hotmail.com Bulletin of Entomological Research, Page 1 of 10 doi:10.1017/S000748531900004X © Cambridge University Press 2019 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S000748531900004X Downloaded from https://www.cambridge.org/core. University of Massachusetts Amherst, on 08 Feb 2019 at 10:21:46, subject to the Cambridge Core terms of use, available at