Composition of volatiles of citrus varieties and their effects on the behavior of Diaphorina citri

Abstract

Currently, Huanglongbing (HLB) is the most devastating citrus disease in the world. Until the moment, there is no resistant variety to the disease pathogens and the management of the disease includes the chemical control of the insect vector, the Asian citrus psyllid Diaphorina citri (ACP). The goal of this study was to identify the attractiveness of citrus varieties to ACP using a four-arm olfactometer and to identify the volatile organic compounds emitted by the analyzed plants. The following varieties were used: 'Valencia', 'Westin' and 'Pera' sweet orange scions, also the rootstocks, 'Rangpur lime', 'Sunki Tropical', and 'HTR059' hybrid. The VOCs were extracted using the SPME technique and identified through GC-MS. 'Sunki Tropical', 'Rangpur lime' and 'Valencia' were more attractive to D. citri than the others varieties. The main compounds found in the least attractive varieties were β-pinene and linalol in 'Pera', β-pinene and decanol in 'Westin', β-caryophyllene and γ-elemene in 'HTR 059'. Therefore, 'HTR 059', 'Pera' and 'Westin' are the varieties indicated to implement actions to prevent the introduction and spread of the disease. 'Valencia', 'Sunki Tropical' and 'Rangpur lime' are the least suitable varieties for cultivation when HLB prevention is required.