Electroantennogram Responses of a Predator, Perillus bioculatus, and its Prey, Leptinotarsa decemlineata, to Plant Volatiles

The two-spotted stinkbug, Perillus bioculatus, is a predator of the Colorado potato beetle (CPB), Leptinotarsa decemlineata. Behavioral tests revealed that P. bioculatus is attracted to potato plants, Solanum tuberosum L. (Solanaceae), infested by the CPB. Electroantennograms from the antennae of P. bioculatus were recorded in response to compounds present in the headspace of CPB-infested potato plants. (Z)-3-Hexen-1-ol and 2-phenylethanol elicited the highest EAG amplitudes. Linalool, 4,8-dimethyl-1,3(E),7-nonatriene, nonanal, decanal, and (R)-(+)-limonene evoked lower EAG amplitudes. The major headspace components -caryophyllene and -selinene produced only weak EAG responses. Antennal sensitivity of the CPB to (Z)-3-hexen-1-ol was higher than that of P. bioculatus, whereas the stinkburg was more sensitive to 2-phenylethanol, -caryophyllene, (R)-(+)-limonene, and decanal. Among these compounds, 2-phenylethanol is of special interest since it was observed to be emitted by potato foliage only after being damaged by CPBs.     

Identification of Semiochemicals Released During Aphid Feeding That Attract Parasitoid Aphidius ervi

Herbivore induced release of plant volatiles mediating the foraging behavior of the aphid parasitoid Aphidius ervi was investigated using the pea aphid, Acyrthosiphon pisum, feeding on broad bean, Vicia faba. Behavioral responses were studied using an olfactometer and a wind tunnel. Volatiles obtained by air entrainment of aphid infested plants were more attractive to A. ervi than those from uninfested plants, in both behavioral bioassays. GC-EAG of both extracts showed a number of peaks associated with responses by A. ervi, but with some differences between extracts. Compounds giving these peaks were tentatively identified by GC-MS and confirmed by comparison with authentic samples on GC, using two columns of different polarity. The activity of pure compounds was further investigated by EAG and wind tunnel assays. Results showed that, of the compounds tested, 6-methyl-5-hepten-2-one was the most attractive for A. ervi females, with linalool, (Z)-3-hexen-1-yl acetate, (E)--ocimene, (Z)-3-hexen-1-ol, and (E)--farnesene all eliciting significantly more oriented flight behavior than a solvent control. Foraging experience significantly increased parasitoid responses to these compounds, with the exception of (E)--farnesene. Time-course GC analysis showed that feeding of A. pisum on V. faba induced or increased the release of several compounds. Release of two of these compounds (6-methyl-5-hepten-2-one and geranic acid) was not induced by the nonhost black bean aphid, Aphis fabae. During the analysis period, production of (E)--ocimene remained constant, but 6-methyl-5-hepten-2-one, linalool, geranic acid, and (E)--farnesene appeared during the first day after A. pisum infestation and increased in concentration with increasing time of aphid feeding.     

Chemicals Used for Host Recognition by the Granary Weevil Parasitoid Lariophagus distinguendus

In order to develop methods for mass rearing of the parasitic wasp Lariophagus distinguendus, we characterized and identified chemicals used by this parasitoid to recognize wheat grains infested by its host, larvae of the granary weevil, Sitophilus granarius, a major pest of stored grain worldwide. Bioassays revealed that drumming and drilling behavior of the parasitoids on grain models of filter paper treated with host feces was as intense as on host-infested grains. Thus, chemicals from feces are highly important to recognize infested grains. Extracts of the feces with hexane or dichloromethane applied on grain models were able to provoke drumming and drilling activity. Hexane extract of feces was as active as infested grain itself. Subsequent fractionation of the hexane extract by adsorption chromatography revealed that highest activity was recovered in the dichloromethane fraction. This fraction was characterized by the presence of -tocopherol, -tocopherol, -tocotrienol, cholesterol, ergostenol, and -sitosterol. Synthetic chemicals in proportions found in the active dichloromethane fraction stimulated drumming behavior in bioassays. The significance of these results with respect to the mass propagation of L. distinguendus as natural enemies for the control of the granary weevil is discussed.     

Attraction to Herbivore-induced Plant Volatiles by the Host-foraging Parasitoid Fly <Emphasis Type="Italic">Exorista japonica</Emphasis>

Responses of the tachinid fly Exorista japonica Townsend to odors from corn plants infested with the fly’s host, the larvae of the noctuid moth Mythimna separata (Walker), were examined in a wind tunnel. Naïve female flies showed a higher rate of landing on M. separata-infested corn plants from which the host larvae had been removed than on artificially damaged or intact corn plants. When paper impregnated with a solution of headspace volatiles collected from host-infested plants was attached to intact plants, females landed on the plants at a high rate. Females also responded to intact plants to which had been attached with paper impregnated with a synthetic blend of nine chemicals identified previously in host-infested plants. There was an optimum concentration of the synthetic blend for the females’ landing. Of the nine chemicals identified previously, four [(E)-4,8-dimethyl-1,3,7-nonatriene, indole, 3-hydroxy-2-butanone, and 2-methyl-1-propanol] released only by host-infested plants were classified as a host-induced blend. The other five [(Z)-3-hexen-1-yl acetate, (E)-2-hexenal, hexanal, (Z)-3-hexen-1-ol, and linalool] were classified as a non-specific blend released not only by infested plants but also by artificially damaged or intact plants. In the wind tunnel, E. japonica females did not respond to intact plants to which paper containing a solution of non-specific blend or host-induced blend was attached. However, they showed a high level of response to a mixture of the non-specific and host-induced blends. These results indicate that naïve E. japonica use a combination of non-specific and host-induced blends as an olfactory cue for locating host-infested plants.     

Chemical analysis of volatiles emitted by Pinus svlvestris after induction by insect oviposition

Gas chromatography – mass spectrometry analyses of the headspace volatiles of Scots pine (Pinus sylvestris) induced by egg deposition of the sawfly Diprion pini were conducted. The odor blend of systemically oviposition-induced pine twigs, attractive for the eulophid egg parasitoid Chrysonotomyia ruforum, was compared to volatiles released by damaged pine twigs (control) that are not attractive for the parasitoid. The mechanical damage inflicted to the control twigs mimicked the damage by a sawfly female prior to egg deposition. The odor blend released by oviposition-induced pine twigs consisted of numerous mono- and sesquiterpenes, which all were also present in the headspace of the artificially damaged control twigs. A quantitative comparison of the volatiles from oviposition-induced twigs and controls revealed that only the amounts of (E)--farnesene were significantly higher in the volatile blend of the oviposition-induced twigs. Volatiles from pine twigs treated with jasmonic acid (JA) also attract the egg parasitoid. No qualitative differences were detected when comparing the composition of the headspace of JA-treated pine twigs with the volatile blend of untreated control twigs. JA-treated pine twigs released significantly higher amounts of (E)--farnesene. However, the JA treatment induced a significant increase of the amount of further terpenoid components. The release of terpenoids by pine after wounding, egg deposition, and JA treatment is discussed with special respect to (E)--farnesene.     

Investigation of the role of diterpenes produced by marine pulmonatesTrimusculus reticulatus andT. conica

The intertidal pulmonate limpetTrimusculus reticulatus, which is found in caves or crevices along the California coast, was previously reported to contain two novel diterpenoids, 6-isovaleroxylabda-8,13-dien-7,15-diol (1) and 2,7-diacetoxy-6-isovaleroxylabda-8,13-dien-15-ol (2). Dissection of the animals prior to extraction revealed that the diterpenoids were concentrated in the mantle, foot, and mucus, but not in the viscera. The presence ofT. reticulatus or its mucus was toxic to veliger larvae of the sabellariid reef-building tube wormPhragmatopoma californica. The major diterpenoid1 was responsible for the observed larvicidal activity. Protection against overgrowth by settling invertebrate larvae is important for the survival of this sessile filter-feeding pulmonate. A related pulmonate,T. conica, which was found in similar intertidal habitats in New Zealand, contained 6-acetoxy-7-isovaleroxylabda-8,13-dien-15-oic acid (3) and 1,7,12,18-tetraacetoxy-cholest-5-en-3-ol (4). The diterpene3 was also localized in the foot, mantle, and mucus ofT. conica but was not larvicidal toP. californica.     

Aggregation arrestant pheromone of the German cockroach,Blattella germanica (L.) (Dictyoptera: Blattellidae): Isolation and structure elucidation of blattellastanoside-A and -B

The aggregation pheromone of the German cockroach,Blattella germanica, consists of attractant and arrestant, which can be detected by olfactometer and choice-chamber assay, respectively. Both were extracted from the frass-contaminated filter paper being used as a shelter. They were separated by solvent partition withn-butanol and water. The arrestant from then-butanol phase was purified by open column chromatography and then successive HPLC isolated two major arrestant components. Spectral evidence from SI-MS, HR-EI-MS, and NMR experiments with pulse techniques provided possible structures as 1-(6-chloro-4,5-epoxy-5-stigmast-3-yl)--d-glucopyranoside and 1-(6-chloro-5-hydroxy-5-stigmast-3-yl)--d-glu-copyranoside, denoted as blattellastanoside-A and blattellastanoside-B, respectively. They represented arrestant activity as median effective doses (ED₅₀) at 0.044 (A) and 3.2 (B) nmol on 1.0 cm² of Whatman No. 1 filter paper.     

Isolation and identification of allelochemicals that attract the larval parasitoid,Cotesia marginiventris (Cresson), to the microhabitat of one of its hosts

Volatiles released from corn seedlings on which beet armyworm larvae were feeding were attractive to females of the parasitoid,Cotesia marginiventris (Cresson), in flight tunnel bioassays. Analyses of the collected volatiles revealed the consistent presence of 11 compounds in significant amounts. They were: (Z)-3-hexenal, (E)-2-hexenal, (Z)-3-hexen-1-ol, (Z)- 3-hexen-1-yl acetate, linalool, (3E)-4,8-dimethyl-1,3,7-nonatriene, indole, -trans-bergamotene, (E)--farnesene, (E)-nerolidol, and (3E,7E)-4,8,12-trimethyl-1, 3,7,ll-tridecatetraene. A synthetic blend of all 11 compounds was slightly less attractive to parasitoid females than an equivalent natural blend. However, preflight experience with the synthetic blend instead of experience with a regular plant-host complex significantly improved the response to the synthetic blend. Our results suggest thatC. marginiventris females, in their search for hosts, use a blend of airborne semiochemicals emitted by plants on which their hosts feed. The response to a particular odor blend dramatically increases after a parasitoid experiences it in association with contacting host by-products.     

Electroantennographic and coupled gas chromatographic-electroantennographic responses of the mediterranean fruit fly,Ceratitis capitata,to male-produced volatiles and mango odor

We have identified five compounds from the headspace of calling male Mediterranean fruit flies (medfly),Ceratitis capitata (Wiedemann), and three compounds from the headspace of ripe mango (Mangifera indica L). using coupled gas chromatographic-electroantennographic (GC-EAG) recordings, coupled gas chromatographic-mass spectrometric (GC-MS) analysis, and electroantennographic (EAG) assays of standards. The male-produced volatiles eliciting responses from female antennae were ethyl-(E)-3-octenoate, geranyl acetate, (E,E)--farnesene, linalool, and indole. An EAG dose-response test of linalool enantiomers and indole with female medfly antennae showed relatively strong EAG activities, but no significant difference between (R)-(-)-linalool and (S)-(+)-linalool. The three mango volatiles were identified as (1S)-(-)--pinene, ethyl octanoate, and-caryophyllene. In addition, a strong antennal response was recorded from a contaminant,-copaene, present in a commercial sample of-caryophyllene. The EAG response amplitudes from both male and female antennae to the above three mango volatiles were significantly greater than to a hexanol control. For both male and female medfly antennae, the greatest EAG responses were elicited by-caryophyllene followed by ethyl octanoate. The mean EAG responses of female antennae to-caryophyllene and (1S)-(-)--pinene were significantly greater than those of male antennae.     

Larval osmeterial secretions of the swallowtails (Papilio)

The larval osmeterial secretions of sixPapilio species examined displayed a remarkable qualitative change at the fourth larval ecdysis. The secretions of 4th (penultimate) instar larvae ofP. machaon, P. memnon, P. helenus, P. bianor, andP. maackii principally comprised mono- and/or sesquiterpenoids. The compounds identified from these species included -pinene, sabinene, -myrcene, limonene, -phellandrene, (Z)--ocimene, (E)--ocimene, -elemene, -caryophyllene, (E)--farnesene, -selinene, (E,E)--farnesene, germacrene-A, germacrene-B, caryophyllene oxide, methyl 3-hydroxy-n-butyrate, and acetic acid. In contrast, the secretion of 4th larval instar ofP. xuthus, although containing similar terpenic compounds, was accompanied by large amounts of aliphatic acids and their esters: isobutyric acid, 2-methylbutyric acid, methyl isobutyrate and methyl 2-methylbutyrate. On the other hand, the osmeterial secretions of 5th (last) instar larvae varied little in quality among the six species, and the identified compounds consisted of isobutyric acid, 2-methylbutyric acid, methyl isobutyrate, ethyl isobutyrate, methyl 2-methylbutyrate, ethyl 2-methylbutyrate, and isovaleric acid, the last of which was specific toP. bianor andP. maackii. The chemical alteration of osmeterial exudate synchronized at the final larval ecdysis with the larval morphological change (particularly in body coloration) that appears to be of defensive significance against predators.     

Single and blended maize volatiles as attractants for diabroticite corn rootworm beetles

Synthetic maize volatiles and analogs dispensed singly and blended were tested for attractiveness to western (WCR, Diabrotica virgifera virgifera) and northern corn rootworm beetles (NCR, D. barberi) in maize fields. Newly identified attractants included syn-benzaldoxime, especially for NCR, and -caryophyllene for WCR females. (±)-Linalool was more effective than was (–)-linalool. Myrcene, (+)--pinene, and (–)--pinene were unattractive. Adding methyl salicylate to (±)-linalool, (+)--terpineol, or -ionone appeared to synergistically increase capture of WCR females, but dispensing the terpenes in binary blends did not. Dose–response data for methyl salicylate, (±)-linalool, and a blend of both compounds confirmed the synergy. -Caryophyllene, but not (–)--pinene, added to the latter blend produced a further synergistic increase in WCR female capture that did not vary with sesquiterpene dose from 1.0 to 100 mg. Indole addition to the same blend caused an increase in WCR female captures indicative of synergy, assuming that each did not individually lure different segments of the WCR female population. The green leaf volatiles (Z)-3-hexenyl acetate and (Z)-3-hexen-1-ol were unattractive alone and had no influence on efficacy of traps baited with 3.3 mg each of (±)-linalool, methyl salicylate, and -caryophyllene. The latter mixture captured about half as many WCR females as did 10 mg of 4-methoxycinnamaldehyde, a potent WCR attractant standard. Substituting -ionone for (±)-linalool yielded a ternary blend that captured more beetles than did the aldehyde and was unaffected by aldehyde addition. Olive oil, which has been used to sustain attractant volatilization, did not affect captures. The results show that the blending of maize volatiles has the potential to greatly improve efficacy of lures having promising applications in corn rootworm population management.     

Ethyl m-Digallate from Red Maple, Acer rubrum L., as the Major Resistance Factor to Forest Tent Caterpillar, Malacosoma disstria Hbn.

An ethanolic extract of red maple (Acer rubrum L.) leaves (RME) applied to trembling aspen (Populus tremuloides Michx.) leaves reduced feeding in choice test assays with forest tent caterpillar larvae (Malacosoma disstria Hbn.) (FTC), whereas a trembling aspen foliage extract, similarly applied, stimulated feeding. Compounds isolated from the RME were gallic acid, methyl gallate, ethyl gallate, m-digallate, ethyl m-digallate, 1-O-galloyl--D-glucose, 1-O-galloyl--L-rhamnose, kaempferol 3-O--D-glucoside, kaempferol 3-O--D-galactoside, kaempferol 3-O--L-rhamnoside, kaempferol-3-O-rhamnoglucoside, quercetin 3-O--D-glucoside, quercetin 3-O--L-rhamnoside and quercetin 3-O-rhamnoglucoside, (–)-epicatechin, (+)-catechin and ellagic acid. All of the gallates, (–)-epicatechin, and kaempferol 3-O--L-rhamnoside deterred feeding on trembling aspen leaf disks when applied at 0.28 mg/cm². The two digallates deterred feeding by 90% and were the most effective. HPLC analysis indicated that ethyl m-digallate is present in amounts 10–100 × higher in RME (2.5–250 mg/g) than any other compound. Thus, ethyl m-digallate appears to be the major compound protecting red maple from feeding by FTC, with a minor contribution from other gallates.     

Identification of Host and Nonhost Semiochemicals of Eucalyptus Woodborer Phoracantha semipunctata by Gas Chromatography–Electroantennography

The host range of the eucalyptus woodborer, Phoracantha semipunctata, is restricted mainly to species of Eucalyptus (Myrtaceae). Volatile semiochemicals possibly involved in host selection and nonhost rejection were identified by high-resolution gas chromatography–electroantennography on samples obtained by air entrainment of foliage from host and nonhost trees. Compounds from the main host E. globulus, active at physiologically significant levels, included 3-hydroxy-2-butanone, 3-methyl1-butanol, a branched epoxyalkane, ethyl 3-methylbutanoate, (Z)-3-hexen1-ol, -pinene, -pinene, p-cymene, 1,8-cineole, limonene, and guaiene. E. camaldulensis gave a similar spectrum of volatiles that also included -terpinene and linalool. The volatiles from E. tereticornis were similar to E. globulus but without ethyl 3-methylbutanoate, (Z)-3-hexen-1-ol, 1,8-cineole, or limonene. The nonhost Pinus pinaster (Pinaceae) yielded active compounds common to the host species, including ethyl 3-methylbutanoate, (Z)-3-hexen-1-ol, -pinene, -pinene, p-cymene, 1,8-cineole, limonene, and linalool but, in addition, myrcene, (E)--ocimene, and -cubebene as candidate nonhost cues. The nonhost Olea europeae (Oleaceae) also shared some active compounds in common with the host species, including 3-hydroxy-2-butanone, 3-methyl-1-butanol, the branched epoxyalkane, ethyl 3-methylbutanoate, (Z)-3-hexen-1-ol, -pinene, but an apparent nonhost cue from this species was the homomonoterpene (E)-4,8-dimethylnona-1,3,7triene, plus other compounds so far unidentified.     

A Novel Approach for Isolation of Volatile Chemicals Released by Individual Leaves of a Plant in situ

A glass chamber designed specifically for collecting volatile chemicals from individual leaves of a plant in situ is described. The effectiveness of the chamber was demonstrated by collecting volatile chemicals from single leaves of two plant species, potato (Solanum tuberosum) and broad bean (Vicia faba), before and after mechanical damage. The glass chamber, in conjunction with thermal desorption, enables reduction of the entrainment time and thereby allows the monitoring of compounds released by leaf damage in successive 5-min periods. An intact broad bean leaf, in the middle of the day, produces small amounts of the green leaf volatiles (E)-2-hexenal and (Z)-3-hexen-1-ol. However, during the first 5 min after mechanical damage, large amounts of (Z)-3-hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol are produced. The decline in production of (Z)-3-hexenal and (E)-2-hexenal is fast, and after 10 min, these compounds reach very low levels. (Z)-3-Hexen-1-ol shows an increase for the first 10 min and then a gradual decline. An intact potato leaf, in the middle of the day, produces very small amounts of the sesquiterpene hydrocarbons -caryophyllene and germacrene-D. After being damaged, the profile of released volatiles is different from that of broad bean. In potato, damage is associated with release of large amounts of green leaf volatiles and sesquiterpene hydrocarbons. Compounds such as (Z)-3-hexenal, (E)-2-hexenal, and (Z)-3-hexen-1-ol are released in high amounts during the first 5 min after damage, but after 10 min, these drop to very low levels. High release associated with damage is also observed for -caryophyllene, (E)--farnesene, germacrene-D, and -bisabolene. The highest level is reached 5 min after damage and 15 min later, these compounds drop to low levels. The significance of compounds released after plant damage is discussed.     

Response of The Lacewing Chrysopa cognata to Pheromones of its Aphid Prey

The lacewing Chrysopa cognata, one of the principal predators of aphids in Korea, was tested for responses to the aphid sex pheromone components (4aS,7S,7aR)-nepetalactone and (1R,4aS,7S,7aR)-nepetalactol and the aphid alarm pheromone (E)--farnesene. Electroantennogram responses were obtained to the sex pheromone components but not to (E)--farnesene. The sex pheromone components were attractive in a Y-tube olfactometer assay and in field trials with water traps, but no attraction was observed to (E)--farnesene.     

Selective Phytotoxic Activity of Withanolides from Iochroma australe to Crop and Weed Species

Phytotoxic effects of Iochroma australe extract and 4,7,20-oxowithanolides were examined in Petri dish bioassays at 10, 100, and 1000 ppm. The extract and the major constituent (17S,20R,22R)-4,7,20-trihydroxy-1oxowitha-2,5,24-trienolide (2) reduced growth of the radicle of the weeds Sorghum halepense (Monoct.) and Chenopodium album (Dicot.). Neither the extract nor withanolides had significant effect on germination or radicle length of the commercial crop species Lactuca sativa. From our experimental data we conclude that the withanolides tested here are natural products with selective herbicidal activity against weed species.     

Defensive steroids from a carrion beetle (Silpha novaboracensis)

Two novel steroids, 3,7-dihydroxy-14-pregn-4-en-15,20-dione (1) and 3,7, 20-trihydroxy-14-pregn-4-en-15-one (4), have been characterized from the rectal gland ofSilpha novaboracensis (Coleoptera: Silphidae). Judging from the function of comparable pregnanes in another species ofSilpha, the compounds may play an antipredator role.Paper No. 81 of the seriesDefense Mechanisms of Arthropods. Paper No. 80 is Eisner, T., Deyrup, M., Jacobs, R., and Meinwald, J.,J. Chem. Ecol. 12:1407–1415.     

Inhibition of β-Glucosidase and Esterase by Tannins from Betula, Salix, and Pinus Species

The reaction of tannin fractions isolated from the bark of Betula, Salix, and Pinus species with two enzymes, -glucosidase and esterase, was investigated. The influence of precipitation to the hydrolytic capacity of -glucosidase also was studied. All tannins studied precipitated -glucosidase and esterase, and moderate differences in the precipitating capacities of the tannins were observed. Interestingly, complex formation between -glucosidase and tannin did not markedly affect the activity of the enzyme. Therefore, complex formation during the insect/herbivore feeding does not necessarily change the defense activity of phenolic glycosides or decrease activity of digestive enzymes.     

Effects of Time After Last Herbivory on the Attraction of Corn Plants Infested with Common Arymworms to a Parasitic Wasp <Emphasis Type="Italic">Cotesia kariyai</Emphasis>

Females of the gregarious endoparasitoid Cotesia kariyai were attracted to a blend of volatiles released from corn plants infested with larvae of their host, the common armyworm (Mythimna separata). We investigated the effects of time after the last infestation (1–168 h) on the attractiveness of corn plants infested by host larvae by using a wind tunnel under laboratory conditions. Immediately after the removal of the larvae, parasitoids were attracted more to plants that had been infested with the larvae than to intact plants (control). This attractiveness gradually decreased with time after the last infestation. The attractiveness of the infested plants was significantly higher than that of intact plants when the time after the last infestation was within 1 day. Fifteen herbivore-induced volatiles were recorded in the headspace of infested corn plants irrespective of time. The amounts of some compounds including (Z)-3-hexen-1-yl acetate, which have already been reported to attract C. kariyai, correlated with the attractiveness. The ecological meaning of the duration of production of C. kariyai attractants is discussed.     

Volatile organic chemicals of a shore-dwelling cyanobacterial mat community

The main components of a cyanobacterial mat community of a hypersaline lake shore consist of edaphic, mat-forming strains (ecophenes), and littoral strains ofOscillatoria animalis Agardh andO. subbrevis Schmidle, other microorganisms associated with these cyanobacteria, several species ofBembidion (Carabidae: Coleoptera), and two halophytic flowering plants:Puccinellia nuttalliana (salt meadow grass) andSalicornia europaea rubra (samphire). The volatile organic compounds of this community are a blend of those emitted by each of these components such as the C₁₇ alka(e)nes, geosmin, 2-methylisoborneol,-cyclocitral,-ionone, dimethyl sulfide, and dimethyl trisulfide of cyanobacteria and associated microorganisms; alcohols, esters, and aldehydes usually associated with flowering plants; and possibly some insect-derived esters, particularly isopropyl tetradecanoate. The dominant compounds were: C₁₁, C₁₃, C₁₅, and C₁₇ alka(e)nes, methyl esters of C₁₆ and C_18:2 acids, isopropyl tetradecanoate, heptanal, 3-octanone and 2-nonanone, the acyclic terpene linalool, and the alcohols 1-heptanol, 1-hexanol, 1-octanol, 3-hexen-1-ol, and 2-octen-1-ol. It is concluded that this community may be distinguished from related communities by its repertoire of volatile organic compounds.