## 3 Discussion  
In this study, we evaluated VOC emissions of three varieties of tomato in healthy and psyllid-infested plants. Previous studies in our research group found that _B. cockerelli_ adults presented a strong oviposition preference toward the domesticated _S. Iycopersicum_ cv. Floradade and a lower preference for _S. Iycopersicum_ cv. Micro-Tom and _S. Iycopersicum_ cv. wild [25]. These differences in the preferences of psyllids could be attributed to VOC blends in healthy plants. For this purpose,  
Figure 4: Volatile organic compounds detected in _Salamun Iycopersicum_ varieties (wild, Floradade and Micro-Tom) from healthy (white bars) and infested (black bars) plants. (**A**) Wild plants with compounds: \(\alpha\)-pinene (1), (+)-4-carene (6), \(\beta\)-phellandrene (9), and caryophyllene (18). (**B**) Floradade plants with compounds: (+)-2-carene (8), (+)-sabinene (11), and phenol, 2,6-bis(1,1-dimethylethyl)-4-(1-methylpropyl) (22). (**C**)Micro-Tom plants with compounds: \(\alpha\)-pinene (1), and \(\beta\)-pinene (5). VOC profiles were obtained from the three varieties for a single bioassay in healthy plants (psyllid-free) and two bioassays in infested tomato plants. Values are means (\(\pm\)5E; healthy \(n=3\); infested \(n=6\)). Level of significance: \({}^{\star}\), \(P<0.05\). (Univariate ANOVA, non-parametric _Kruskal-Wallis_ test at \(P=<0.05\)). we performed some bioassays and the VOC profiles were obtained for healthy and infested plants (Table 1). Considering the qualitative differences among varieties of tomato VOC, we speculated that some volatiles could act as attractants or repellents for _B. cockerelli_ adults, even though in this study we did not perform an electroantennography analysis to validate the results. In similar studies, healthy tomato plants (_S. lycopersicum_ cv. Castlemart) emitted 11 VOCs in the constitutive blend. \(\alpha\)-pinene, \(\circ\)-cymene, (+)-4-carene, and \(\beta\)-phellandrene were found among these compounds [24]. The shared compounds with VOC patterns from the headspace of healthy tomato plants were obtained from three varieties, although our results triggered 14 VOCs for wild, 17 VOCs for Floradade and 4 VOCs for Micro-Tom (Table 1). The oviposition behavior by _B. cockerelli_ in solanaceous crops is mediated through the olfactory and visual stimuli to locate their hosts [26]. Some factors, such as natal host plant and plant phenology, also improve the settling and oviposition [23]. In other studies, wild varieties of tomato (_Solanum peruvianum_) that bore the _Mi-1.2_ gene, presented a reduced oviposition of _B. cockerelli_, compared with susceptible varieties that lacked the gene [27]. In field conditions, _B. cockerelli_ showed a strong preference for potato and tomato compared with eggplant and pepper [26]. To determine whether nymph feeding promoted differences in VOC emissions in the three varieties of tomato, two herbivory bioassays were performed on tomato leaves. In Floradade-nymph interactions, \(\alpha\)-thujene was detected as the most abundant compound after 2 h of herbivory (Table 1). This compound was detected in basil plants emissions (_Ocimum gratissimum_ L. and _O. basilicum_ L.) and may be involved in the oviposition deterrence against _Tuta absoluta_[28]. Regarding VOCs induced in wild plants, \(\beta\)-phellandrene and (+)-4-carene were detected as the most abundant ones (Table 1). This could correlate with the reduced oviposition of _B. cockerelli_[25] and also with the role of monoterenes involved with repellence in solanaceous plants against whiteflies, such as terpenenes and phellandrenes [9]. Interestingly, Micro-Tom plants infested with nymphs presented a reduced number of VOCs emitted, and \(\alpha\)-pinene was the most abundant one (Table 1). Besides, we did not perform leaves surface analysis to evaluate the differences in trichome numbers. The synthesis of diverse trichome-borne metabolites influences host plant selection by herbivores under natural conditions [29]. [PERSON] et al.