###### Abstract  
Herbivore-Induced Plant Volatiles (HIPVs) are volatile signals emitted by plants to deter herbivores and attract their natural enemies. To date, it is unknown how Lychee plants, _Litchi chinensis_, respond to the induction of leaf galls (erinea) caused by the lychee erinose mite (LEM), _Aceria litchi_. Aiming to reveal the role of HIPVs in this plant-mite interaction, we investigated changes in the volatile profile of lychee plants infested by LEM and their role on LEM preferences. The volatile profile of uninfested (flower buds, fruit, leaves and new leaf shoots) and infested plant tissue were characterized under different levels of LEM infestation. Volatiles were collected using head-space-solid phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) analyses. Fifty-eight volatiles, including terpenoids, alcohols, aldehydes, alkanes, esters, and ketones classes were identified. Using dual-choice bioassays, we investigated the preference of LEM to uninfested plant tissues and to the six most abundant plant volatiles identified. Uninfested new leaf shoots were the most attractive plant tissues to LEM and LEM attraction or repellence to volatiles were mostly influenced by compound concentration. We discuss possible applications of our findings in agricultural settings. h _Horticule_, 1 Tropical Research and Education Center, University of Florida, 18905 SW 280 ST, Homestead, FL 33031, USA; [EMAIL_ADDRESS] (M.A.C. ); [EMAIL_ADDRESS] (D.C.)  
T.I.N.N.A.C. and other VOCs, emitted in response to herbivory, allow parasitoids and predators to distinguish infested from non-infested plants, helping them locate their prey. For instance, Lima bean [8], apple [9], and cucumber [10] plants infested with the two-spotted spider mite (_Tetranychus urticae_, Acari: Tetranychidae) attracted significantly more natural enemies than non-infested plants. The composition of HIPVs can vary significantly within plant species when attacked by the same herbivore. For example, feeding by _T. urticae_ induces different HIPV blends from a range of host plants [11], and the predatory mite _Plytoiseilus persimilis_ (Acari: Phytoseiidae) is attracted to different HIPV blends from different _T. urticae_ -damaged plant species [12]. In addition to directly repelling herbivores [13] and indirectly attracting natural enemies, HIPV's are also involved in within-plant communication [14; 15] and plant-plant communication in response to herbivore attack [16; 17; 18; 19]. Herbivory releases distinct volatile blends in damaged plants that are potent elicitors of defenses in systemic uninduced leaves of the same plant or nearby plants [20; 21; 22]. Since HIPVs can be used to recruit natural enemies and repel herbivores, they can be implemented as a sustainable Integrated Pest Management (IPM) strategy for controlling plant pests. Furthermore, transgenic plants can be engineered to enhance emission of VOCs to increase attraction of natural enemies [23; 24; 25; 26] and repel important pests [27; 28]. Lychee (_Litchi chinensis_ Sonn., Sapindaceae) is a commercially important fruit native to Asia that has been cultivated by several countries in the tropical and subtropical regions of the world [29]. A tiny eriophyoid mite called the lychee erinose mite (LEM), _Aceria litchi_ (Keifer) (Acari: Eriophyidae), threatens lychee production worldwide as it infests every plant tissue. LEM is highly host-specific and is only known to attack lychee [30; 31]. Upon feeding, LEM induces the formation of a gall called \"erineum\" which consists of proliferations of hypertrophic trichomes [32] that undergo several stages of development. In early erineum stages, when mite infestations are low, the affected tissue becomes distorted, and white hairs develop as feltlike masses. As mite populations grow, a denser white erineum becomes apparent, and when populations peak, the erineum turns into an amber color. At its final stage, the erineum turns dark in color followed by tissue necrosis [30].