## 3 Discussion  
To the best of our knowledge, the volatiles released by the roots of \(V\). _corymbosum_ have not yet been explored. In this study, we demonstrated that _V. corymbosum_ root volatiles comprise a complex blend of VOCs altered by the herbivory of _A. superciliosus_ larva. Through this work, we contributed to increasing the list of compounds reported as volatiles emitted by _V. corymbosum_, either constitutive or induced by herbivory. VOCs from _V. corymbosum_ have been extensively studied in aboveground systems, including the VOCs released by flowers, fruits, and leaves [20; 29; 30; 31; 32; 33; 34]. It should also be noted that, typically, the volatile root profile triggered by herbivory may differ from the aerial profile of the plant [35]. In addition, we demonstrated that some of the root volatiles evaluated in this study elicited chemotaxis to _S. australe_ JIs, a promising entomopathogen for the key pest _A. superciliosus_ in the blueberry crop in the south of Chile. Our results showed that the blend of VOCs released by the _V. corymbosum_ roots comprised terpen, esters, aliphatic hydrocarbons, alcohols, ketones, and other compounds. Terpenes compose the most chemically and structurally diverse family of natural products [36]. Their release by damaged roots has been shown to recruit natural enemies of herbivores [37]. This belowground tri-trophic interaction was described in the seminal work of [PERSON] et al. [3], where maize roots released the sesquiterpene (_E_)-\(\beta\)-caryophyllene in response to feeding of _D. virgifera virgifera_. In this respect, our results showed a large increase in the emission of 2-carene, \(\alpha\)-terpineol, linalool, and limonene and a moderate increase in the emission of cis-myrtanol and 3-octanone. We also observed a diminution of 4,8-dimethyl-1,7-nonadien-4-ol, eucalypt, and myrcenol. [PERSON] et al. [9] found that linalool was reduced in _Malus domestica_ roots in response to _Melolontha melolontha_ L. (Coleoptera: Scarabaeidae) larval feeding. In the same study, these authors reported the emission of methyl salicate in response to root herbivory being absent in the control plants. In contrast, we found a large reduction in the emission of methyl salicate in response to root herbivory by _A. superciliosus_ in _V. corymbosum_. The direct response of EPNs toward methyl salicate has not been intensely studied in the scientific literature. In citrus plants, foliar application of this compound acted as an elicitor of HIPVs in roots, resulting in recruitment of the EPN _Steinrenema diappresi_ [PERSON] & [PERSON] (Rhabditida: Steinernematidae) [38; 39]. In our bioassays, the attraction of _S. australe_ to all five tested concentrations of methyl salicate suggests that the JIs positively respond to this compound, even at low concentrations. On the other hand, 10-undecyn-1-ol increased in _V. corymbosum_ roots in response to _A. superciliosus_ herbivory. The presence of this alcohol in plant extracts has been associated either with antimicrobial activity [40] or as a precursor for laboratory synthesis of moth pheromones [41; 42]. However, there are no reports regarding its potential role as an EPN recruiter by plants. Our findings demonstrated the attractiveness of _S. australe_ JIs to 10-undecyn-1-ol in chemotaxis assays, making this result an interesting subject for further studies. In terms of the terpenoids, linalool was not abundant in either _A. superciliosus_-infested or -uninfested root conditions. Although linalool has been reported to have limited diffusion into the soil and to be highly susceptible to degradation [43], we decided to include linalool in our profile of selected compounds because it has been reported as an HIPV-causing mixed response upon EPNs in similar studies. For instance, in olfactometric bioassays using sand as a substrate, linalool was not attractive to _Steinrenema diappresi_, _Steinerrema ribrave_ ([PERSON], [PERSON], and [PERSON]), or _Heterorhabditis indica_ [PERSON], [PERSON] & [PERSON] [44].