Expression of lima bean terpene synthases in rice enhances recruitment of a beneficial enemy of a major rice pest

Volatile terpenoids play a key role in plant defence against herbivory by attracting parasitic wasps. We identified seven terpene synthase genes from lima bean, Phaseolus lunatus L. following treatment with either the elicitor alamethicin or spider mites, Tetranychus cinnabarinus. Four of the genes (Pltps2, Pltps3, Pltps4 and Pltps5) were up‐regulated with their derived proteins phylogenetically clustered in the TPS‐g subfamily and PlTPS3 positioned at the base of this cluster. Recombinant PlTPS3 was able to convert geranyl diphosphate and farnesyl diphosphate to linalool and (E)‐nerolidol, the latter being precursor of the homoterpene (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT). Recombinant PlTPS4 showed a different substrate specificity and produced linalool and (E)‐nerolidol, as well as (E,E)‐geranyllinalool from geranylgeranyl diphosphate. Transgenic rice expressing Pltps3 emitted significantly more (S)‐linalool and DMNT than wild‐type plants, whereas transgenic rice expressing Pltps4 produced (S)‐linalool, DMNT and (E,E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene (TMTT). In laboratory bioassays, female Cotesia chilonis, the natural enemy of the striped rice stemborer, Chilo suppressalis, were significantly attracted to the transgenic plants and their volatiles. We further confirmed this with synthetic blends mimicking natural rice volatile composition. Our study demonstrates that the transformation of rice to produce volatile terpenoids has the potential to enhance plant indirect defence through natural enemy recruitment.     

Attraction of codling moth males to apple volatiles

The attraction of the codling moth, Cydia pomonella, to apple volatile compounds known to elicit an antennal response was tested both in the field and in a wind tunnel. In the field, (E)‐β‐farnesene captured male moths. The addition of other apple volatiles, including (E,E)‐α‐farnesene, linalool, or (E,E)‐farnesol to (E)‐β‐farnesene did not significantly augment trap catch. Few females were caught in traps which also caught male moths, but female captures were not significantly different from blank traps. In the wind tunnel, males were attracted to (E,E)‐farnesol, but not to (E)‐β‐farnesene. The addition of (E,E)‐α‐farnesene to (E)‐β‐farnesene had a synergistic effect on male attraction. The male behavioural sequence elicited by plant volatiles, including upwind flight behaviour, was indistinguishable from the behaviour elicited by sex pheromone.     

Antennal and behavioural response of codling moth Cydia pomonella to plant volatiles

Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3‐hexenol, (Z)3‐hexenyl benzoate, (Z)3‐hexenyl hexanoate, (±)‐linalool and E,E‐α‐farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)‐2,4‐decadienoate, and its corresponding aldehyde, E,E‐2,4‐decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)‐α‐farnesene, (E)‐beta‐farnesene and ethyl (E,Z)‐2,4‐decadienoate. The aldehyde E,E‐2,4‐decadienal had an antagonistic effect when added to the above mixture.     

Molecular and biochemical evolution of maize terpene synthase 10, an enzyme of indirect defense

Maize plants attacked by lepidopteran larvae emit a volatile mixture that consists mostly of the sesquiterpene olefins, (E)-α-bergamotene and (E)-β-farnesene. These volatiles are produced by the herbivore-induced terpene synthase TPS10 and attract natural enemies to the damaged plants. A survey of volatiles in maize lines and species of teosinte showed that the TPS10 products (E)-α-bergamotene and (E)-β-farnesene are consistently induced by herbivory, indicating that release of TPS10 volatiles is a defense trait conserved among maize and its wild relatives. Sequence comparison of TPS10 from maize and its apparent orthologs from four teosinte species demonstrated stabilizing selection on this defense trait. The teosinte volatiles and the enzymatic activity of the apparent TPS10 orthologs were not completely uniform but varied in the ratio of (E)-α-bergamotene to (E)-β-farnesene products formed. We identified a single amino acid in the active center which determines the ratio of (E)-α-bergamotene to (E)-β-farnesene and has changed during the evolution of maize and teosinte species. Feeding experiments with the substrate (Z,E)-farnesyl diphosphate revealed that this amino acid controls the rate of isomerization of the (E,E)-farnesyl carbocation intermediate to the (Z,E)-configuration.     

Aroma Profile of Rubus ulmifolius Flowers and Fruits During Different Ontogenetic Phases

The chemical composition of spontaneous volatile emission from Rubus ulmifolius flowers and fruits during different stages of development was evaluated by HS‐SPME‐GC/MS. In total, 155 chemical compounds were identified accounting 84.6 – 99.4% of whole aroma profile of flowers samples and 92.4 – 96.6% for fruit samples. The main constituents were α‐copaene, β‐caryophyllene, germacrene D, (E,E)‐α‐farnesene, 1,7‐octadien‐3‐one,2‐methyl‐6‐methylene, tridecane, (E)‐2‐hexenol acetate, (E)‐3‐hexenol acetate and cyperene. The results give a chemotaxonomic contribution to the characterization of the VOCs emitted from flowers and fruits during their ontogenic development.     

Evolution of TPS20-related terpene synthases influences chemical diversity in the glandular trichomes of the wild tomato relative Solanum habrochaites

A systematic screen of volatile terpene production in the glandular trichomes of 79 accessions of Solanum habrochaites was conducted and revealed the presence of 21 mono‐ and sesquiterpenes that exhibit a range of qualitative and quantitative variation. Hierarchical clustering identified distinct terpene phenotypic modules with shared patterns of terpene accumulation across accessions. Several terpene modules could be assigned to previously identified terpene synthase (TPS) activities that included members of the TPS‐e/f subfamily that utilize the unusual cis‐prenyl diphosphate substrates neryl diphosphate and 2z,6z‐farnesyl diphosphate. DNA sequencing and in vitro enzyme activity analysis of TPS‐e/f members from S. habrochaites identified three previously unassigned enzyme activities that utilize these cisoid substrates. These produce either the monoterpenes α‐pinene and limonene, or the sesquiterpene 7‐epizingiberene, with the in vitro analyses that recapitulated the trichome chemistry found in planta. Comparison of the distribution of S. habrochaites accessions with terpene content revealed a strong preference for the presence of particular TPS20 alleles at distinct geographic locations. This study reveals that the unusually high intra‐specific variation of volatile terpene synthesis in glandular trichomes of S. habrochaites is due at least in part to evolution at the TPS20 locus.     

Influence of volatile compounds from herbivore‐damaged soybean plants on searching behavior of the egg parasitoid Telenomus podisi

Parasitoids use herbivore‐induced plant volatiles (HIPVs) to locate their hosts. However, there are few studies in soybean showing the mechanisms involved in the attraction of natural enemies to their hosts and prey. The objective of this study was to evaluate the influence of volatile organic compounds (VOCs) of soybean, Glycine max (L.) Merr. (Fabaceae) (cv. Dowling), that were induced after injury caused by Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), on the searching behavior of the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae). Four HIPVs from soybean, (E,E)‐α‐farnesene, methyl salicylate, (Z)‐3‐hexenyl acetate, and (E)‐2‐octen‐1‐ol, were selected, prepared from standards at various concentrations (10^?6 to 10^?1 m ), and tested individually and in combinations using a two‐choice olfactometer (type Y). Telenomus podisi displayed a preference only for (E,E)‐α‐farnesene at 10^?5 m when tested individually and compared to hexane, but they did not respond to the other compounds tested individually at any concentration or when combinations of these compounds were tested. However, the parasitoids stayed longer in the olfactometer arm with the mixture of (E,E)‐α‐farnesene + methyl salicylate at 10^?5 m than in the arm containing hexane. The results suggest that (E,E)‐α‐farnesene and methyl salicylate might help T. podisi to determine the presence of stink bugs on a plant. In addition, bioassays were conducted to compare (E,E)‐α‐farnesene vs. the volatiles emitted by undamaged and E. heros‐damaged plants, to evaluate whether (E,E)‐α‐farnesene was the main cue used by T. podisi or whether other minor compounds from the plants and/or the background might also be used to locate its host. The results suggest that minor volatile compounds from soybean plants or from its surroundings are involved in the host‐searching behavior of T. podisi.     

Production of multiple terpenes of different chain lengths by subcellular targeting of multi-substrate terpene synthase in plants

Multi-substrate terpene synthases (TPSs) are distinct from typical TPSs that react with a single substrate. Although in vitro activity of few multi-substrate TPSs have been reported, in vivo characterization has not been well investigated for most of them. Here, a new TPS from Cananga odorata, CoTPS5, belonging to TPS-f subfamily was functionally characterized in vitro as well as in vivo. CoTPS5 reacted with multiple prenyl-pyrophosphate substrates of various chain lengths as a multi-substrate TPS. It catalyzed the formation of (E)-β-ocimene, (E,E)-α-farnesene and α-springene from geranyl pyrophosphate, (E,E)-farnesyl pyrophosphate and geranylgeranyl pyrophosphate, respectively. Upon transient expression in Nicotiana benthamiana, CoTPS5 localized to cytosol and produced only (E,E)-α-farnesene. However, expression of plastid-targeted CoTPS5 in N. benthamiana resulted in biosynthesis of all three compounds, (E)-β-ocimene, (E,E)-α-farnesene and α-springene. Similarly, transgenic Arabidopsis plants overexpressing plastid-targeted CoTPS5 showed stable and sustainable production of (E)-β-ocimene, (E,E)-α-farnesene and α-springene. Moreover, their production did not affect the growth and development of transgenic Arabidopsis plants. Our results demonstrate that redirecting multi-substrate TPS to a different intracellular compartment could be an effective way to prove in vivo activity of multi-substrate TPSs and thereby allowing for the production of multiple terpenoids simultaneously in plants.     

An ecological cost of plant defence: attractiveness of bitter cucumber plants to natural enemies of herbivores

Plants produce defences that act directly on herbivores and indirectly via the attraction of natural enemies of herbivores. We examined the pleiotropic effects of direct chemical defence production on indirect defence employing near‐isogenic varieties of cucumber plants (Cucumis sativus) that differ qualitatively in the production of terpenoid cucurbitacins, the most bitter compounds known. In release–recapture experiments conducted in greenhouse common gardens, blind predatory mites were attracted to plants infested by herbivorous mites. Infested sweet plants (lacking cucurbitacins), however, attracted 37% more predatory mites than infested bitter plants (that produce constitutive and inducible cucurbitacins). Analysis of the headspace of plants revealed that production of cucurbitacins was genetically correlated with large increases in the qualitative and quantitative spectrum of volatile compounds produced by plants, including induced production of (E )‐β‐ocimene (3E )‐4,8‐dimethyl‐1,3,7‐nonatriene, (E,E)‐α‐farnesene, and methyl salicylate, all known to be attractants of predators. Nevertheless, plants that produced cucurbitacins were less attractive to predatory mites than plants that lacked cucurbitacins and predators were also half as fecund on these bitter plants. Thus, we provide novel evidence for an ecological trade‐off between direct and indirect plant defence. This cost of defence is mediated by the effects of cucurbitacins on predator fecundity and potentially by the production of volatile compounds that may be repellent to predators.     

Genetic control of α‐farnesene production in apple fruit and its role in fungal pathogenesis

Terpenes are important compounds in plant trophic interactions. A meta‐analysis of GC‐MS data from a diverse range of apple (Malus × domestica) genotypes revealed that apple fruit produces a range of terpene volatiles, with the predominant terpene being the acyclic branched sesquiterpene (E,E)‐α‐farnesene. Four quantitative trait loci (QTLs) for α‐farnesene production in ripe fruit were identified in a segregating ‘Royal Gala’ (RG) × ‘Granny Smith’ (GS) population with one major QTL on linkage group 10 co‐locating with the MdAFS1 (α‐farnesene synthase‐1) gene. Three of the four QTLs were derived from the GS parent, which was consistent with GC‐MS analysis of headspace and solvent‐extracted terpenes showing that cold‐treated GS apples produced higher levels of (E,E)‐α‐farnesene than RG. Transgenic RG fruit downregulated for MdAFS1 expression produced significantly lower levels of (E,E)‐α‐farnesene. To evaluate the role of (E,E)‐α‐farnesene in fungal pathogenesis, MdAFS1 RNA interference transgenic fruit and RG controls were inoculated with three important apple post‐harvest pathogens [Colletotrichum acutatum, Penicillium expansum and Neofabraea alba (synonym Phlyctema vagabunda)]. From results obtained over four seasons, we demonstrate that reduced (E,E)‐α‐farnesene is associated with decreased disease initiation rates of all three pathogens. In each case, the infection rate was significantly reduced 7 days post‐inoculation, although the size of successful lesions was comparable with infections on control fruit. These results indicate that (E,E)‐α‐farnesene production is likely to be an important factor involved in fungal pathogenesis in apple fruit.     

Isolation of cDNAs and functional characterisation of two multi-product terpene synthase enzymes from sandalwood, Santalum album L

Sandalwood, Santalum album (Santalaceae) is a small hemi-parasitic tropical tree of great economic value. Sandalwood timber contains resins and essential oils, particularly the santalols, santalenes and dozens of other minor sesquiterpenoids. These sesquiterpenoids provide the unique sandalwood fragrance. The research described in this paper set out to identify genes involved in essential oil biosynthesis, particularly terpene synthases (TPS) in S. album, with the long-term aim of better understanding heartwood oil production. Degenerate TPS primers amplified two genomic TPS fragments from S. album, one of which enabled the isolation of two TPS cDNAs, SamonoTPS1 (1731 bp) and SasesquiTPS1 (1680 bp). Both translated protein sequences shared highest similarity with known TPS from grapevine (Vitis vinifera). Heterologous expression in Escherichia coli produced catalytically active proteins. SamonoTPS1 was identified as a monoterpene synthase which produced a mixture of (+)-α-terpineol and (−)-limonene, along with small quantities of linalool, myrcene, (−)-α-pinene, (+)-sabinene and geraniol when assayed with geranyl diphosphate. Sesquiterpene synthase SasesquiTPS1 produced the monocyclic sesquiterpene alcohol germacrene D-4-ol and helminthogermacrene, when incubated with farnesyl diphosphate. Also present were α-bulnesene, γ-muurolene, α- and β-selinenes, as well as several other minor bicyclic compounds. Although these sesquiterpenes are present in only minute quantities in the distilled sandalwood oil, the genes and their encoded enzymes described here represent the first TPS isolated and characterised from a member of the Santalaceae plant family and they may enable the future discovery of additional TPS genes in sandalwood.     

Patterns in Volatile Emission of Different Aerial Parts of Caper (Capparis spinosa L.)

We analyzed the spontaneous volatile emission of different aerial parts of the caper (Capparis spinosa L.) by HS‐SPME‐GC/MS. We identified 178 different compounds of which, in different proportions based on the sample type, the main ones were (E)‐β‐ocimene, methyl benzoate, linalool, β‐caryophyllene, α‐guaiene, germacrene D, bicyclogermacrene, germacrene B, (E)‐nerolidol, isopropyl tetradecanoate, and hexahydrofarnesyl acetone. The multivariate statistical analyses seem to point out that the parameter leading the emission patterns is the function of the analyzed sample; the flower samples showed differences in the emission profile between their fertile and sterile portions and between the other parts of the plant. The green parts emission profiles group together in a cluster and are different from those of seeds and fruits. We also hydrodistilled fully bloomed caper flowers, whose volatile oil showed significant differences in the composition from those of other parts of the plant reported.     

Four terpene synthases produce major compounds of the gypsy moth feeding-induced volatile blend of Populus trichocarpa

After herbivore damage, many plants increase their emission of volatile compounds, with terpenes usually comprising the major group of induced volatiles. Populus trichocarpa is the first woody species with a fully sequenced genome, enabling rapid molecular approaches towards characterization of volatile terpene biosynthesis in this and other poplar species. We identified and characterized four terpene synthases (PtTPS1-4) from P. trichocarpa which form major terpene compounds of the volatile blend induced by gypsy moth (Lymantria dispar) feeding. The enzymes were heterologously expressed and assayed with potential prenyl diphosphate substrates. PtTPS1 and PtTPS2 accepted only farnesyl diphosphate and produced (−)-germacrene D and (E,E)-α-farnesene as their major products, respectively. In contrast, PtTPS3 and PtTPS4 showed both mono- and sesquiterpene synthase activity. They produce the acyclic terpene alcohols linalool and nerolidol but exhibited opposite stereospecificity. qRT-PCR analysis revealed that the expression of the respective terpene synthase genes was induced after feeding of gypsy moth caterpillars. The TPS enzyme products may play important roles in indirect defense of poplar to herbivores and in mediating intra- and inter-plant signaling.     

Testing semiochemicals from aphid,plant and conspecific: attraction of Harmonia axyridis

Abstract Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds. Nowadays, no biological control method is available to reduce the populations of this harmful coccinellid. Attractants and semiochemicals seem to be the best alternative but only few studies have tested the impact of semiochemicals on this Asian lady beetle. In this work, through wind‐tunnel experiments, semiochemicals from aphids (Z,E‐nepetalactone, [E]‐β‐farnesene, α‐pinene and β‐pinene), from coccinellids ([‐]‐β‐caryophyllene) and from the nettle Urtica dioica L. were evaluated as potential attractants. The nettle volatile compounds ([Z]‐3‐hexenol and [E]‐2‐hexenal) were extracted using a Clevenger Apparatus^® and identified by headspace gas chromatography–mass spectroscopy. In the wind‐tunnel experiments, the main components of the aphid alarm pheromone as well as a component of the aphid sexual pheromone strongly attracted both sexes of the Asian lady beetle while (‐)‐β‐caryophyllene only attracted few individuals and had no impact on the males. The nettle extract as well as the (Z)‐3‐hexenol oriented both males and females to the odor source. The (E)‐2‐hexenal was shown to have no effect on females even if this green leaf volatile attracted males. Because Z,E‐nepetalactone was identified as the most efficient attractant in the wind‐tunnel experiments, this volatile was also tested in a potato field where H. axyridis has been showed to respond to this semiochemical. This study highlighted that Z,E‐nepetalactone orientated the Asian lady beetle H. axyridis under natural conditions, indicating that this volatile compound could certainly help for an efficient biological control approach against this invasive specie.     

Sexual behavior and male volatile compounds in wild and mass‐reared strains of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae) held under different colony management regimes

We compared the calling and mating behavior and volatile release of wild males Anastrepha ludens (Loew) with males from 4 mass‐reared strains: (i) a standard mass‐reared colony (control), (ii) a genetic sexing strain (Tap‐7), (iii) a colony started from males selected on their survival and mating competitiveness abilities (selected), and (iv) a hybrid colony started by crossing wild males with control females. Selected and wild males were more competitive, achieving more matings under field cage conditions. Mass‐reared strains showed higher percentages of pheromone calling males under field conditions except for Tap‐7 males, which showed the highest percentages of pheromone calling males under laboratory cage conditions. For mature males of all strains, field‐cage calling behavior increased during the last hour before sunset, with almost a 2 fold increase exhibited by wild males during the last half hour. The highest peak mating activity of the 4 mass‐reared strains occurred 30 min earlier than for wild males. By means of solid phase microextraction (SPME) plus gas chromatography‐mass spectrometry (GC‐MS), the composition of volatiles released by males was analyzed and quantified. Wild males emitted significantly less amounts of (E,E)‐α‐farnesene but emitted significantly more amounts of (E,E)‐suspensolide as they aged than mass‐reared males. Within the 4 mass‐reared strains, Tap‐7 released significantly more amounts of (E,E)‐α‐farnesene and hybrid more of (E,E)‐suspensolide. Differences in chemical composition could be explained by the intrinsic characteristics of the strains and the colony management regimes. Characterization of calling behavior and age changes of volatile composition between wild and mass‐reared strains could explain the differences in mating competitiveness and may be useful for optimizing the sterile insect technique in A. ludens.     

Pheromone pre-exposure and mating modulate codling moth (Lepidoptera: Tortricidae) response to host plant volatiles

Abstract 1 Two codling moth Cydia pomonella kairomonal attractants, ethyl (E,Z)‐2,4‐decadienoate (pear ester) and (E)‐β‐farnesene, were tested in an insecticide‐sprayed apple orchard and an orchard treated for mating disruption with synthetic pheromone (E,E)‐8,10‐dodecadienol (codlemone). Male captures with pear ester were higher in the pheromone‐treated than in the insecticide‐treated orchard, whereas captures with (E)‐β‐farnesene were not different. Subsequent wind tunnel experiments confirmed that pre‐exposure to sex pheromone codlemone increased the behavioural response of codling moth males to pear ester. This supports the idea that male attraction to the plant volatile pear ester and sex pheromone codlemone is mediated through the same sensory channels. 2 Pear ester is a bisexual codling moth attractant and even captures of female moths were significantly increased in the pheromone‐treated orchard. In the laboratory wind tunnel, pheromone pre‐exposure had no effect on female response to pear ester, but significantly more mated than unmated codling moth females flew upwind towards a pear ester source. Differences in mating status in insecticide‐treated vs. pheromone‐treated orchards may thus account for the differences in female trap captures with pear ester. 3 These findings are important with respect to monitoring of codling moth with pear ester in mating disruption orchards. They also emphasize the importance of host plant volatiles in pheromone‐mediated mating disruption, which has been neglected to date.     

Effects of prohydrojasmon‐treated corn plants on attractiveness to parasitoids and the performance of their hosts

We investigated the effect of prohydrojasmon [propyl (1RS,2RS)‐(3‐oxo‐ 2‐pentylcyclopentyl) acetate] (PDJ) treatment of intact corn plants, on their attractiveness to the specialist endoparasitoid, Cotesia kariyai Watanabe (Hymenoptera: Braconidae), and on the performance of the common armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae) under laboratory conditions. Attractiveness of C. kariyai to PDJ‐treated plants was studied in a wind tunnel, whereas performance of M. separata larvae was tested in plastic cages. The attractiveness of the treated plants increased with concentrations of PDJ increasing to 2 mm , which was equivalent to the attractiveness of host‐infested plants. PDJ‐treated corn plants emitted 16 volatile compounds (α‐pinene, β‐myrcene, (Z)‐3‐hexenyl acetate, limonene, (E)‐β‐ocimene, linalool, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, (+)‐cyclosativene, ylangene, (E)‐β‐farnesene, (E, E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene, α‐bergamotene, γ‐cadinene, δ‐cadinene, α‐muulolene and nerolidol), most of which were observed in the headspace of host‐infested corn plants with some quantitative and qualitative differences. We also tested the effects of PDJ treatment on the performance of M. separata larvae. The survival rates of the larval and pupal stages were significantly lower at 2 mm level of PDJ. A significant decrease in weight at 6th stadium larvae was observed only at 2 mm level of PDJ. In contrast, PDJ treatment at all PDJ concentration levels caused significant reduction in weight of pupal stage as compared to control. These data suggested that PDJ, originally developed as a plant growth regulator, especially to induce coloring of fruits, has the potential to induce direct and indirect defenses in corn plants against common armyworm, M. separata.     

Changes in the volatile profile of four cultivars of quince (Cydonia oblonga) produced by codling moth (Cydia pomonella) infestation

The production of quince (Cydonia oblonga Miller) is affected worldwide by codling moth (Cydia pomonella L.), an oligophagous pest. In this study, volatile compounds in healthy and infested fruits were collected from four cultivars of quince: Champion, Portugal, Smyrna and INTA 147. Volatiles were extracted by SPME and analyzed by GC-MS. Up to 30 compounds were identified in the volatile profiles of uninfested quinces, ranging from 90.9% to 98.4% of the total relative abundance. The volatile profile of all four cultivars of quince was similar, with (E,E)-α-farnesene and octanoic acid- ethyl ester as the main components. Infested fruits presented increased levels of (E,E)-α-farnesene, while minor compounds decreased significantly. Champion and Smyrna varieties might be more susceptible cultivars to infestation as their healthy fruits presented the highest contents of (E,E)-α-farnesene and Pear Ester, both codling moth kairomones. The role of these highly recognized kairomones in the chemical ecology of codling moth in quince is discussed.