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1.
Elie A. Dannon Manuele Tamò Arnold Van Huis Marcel Dicke 《Journal of chemical ecology》2010,36(10):1083-1091
The parasitoid wasp Apanteles taragamae is a promising candidate for the biological control of the legume pod borer Maruca vitrata, which recently has been introduced into Benin. The effects of volatiles from cowpea and peabush flowers and Maruca vitrata larvae on host selection behavior of the parasitoid Apanteles taragamae were investigated under laboratory conditions by using a Y-tube olfactometer. Na?ve and oviposition-experienced female wasps
were given a choice between several odor sources that included (1) uninfested, (2) Maruca vitrata-infested, and (3) mechanically damaged cowpea flowers, as well as (4) stem portions of peabush plants carrying leaves and
flowers, (5) healthy M. vitrata larvae, and moribund (6), and live (7) virus-infected M. vitrata larvae. Responses of na?ve and oviposition-experienced female wasps did not differ for any of the odor source combinations.
Wasps were significantly attracted to floral volatiles produced by cowpea flowers that had been infested with M. vitrata larvae and from which the larvae had been removed. Apanteles taragamae females also were attracted to Maruca vitrata-infested flowers after removal of both the larvae and their feces. Female wasps discriminated between volatiles from previously infested flowers and mechanically damaged flowers. Uninfested
cowpea flowers attracted only oviposition-experienced wasps that had received a rewarding experience (i.e. the parasitization
of two M. vitrata larvae feeding on cowpea flowers) before the olfactometer test. Wasps also were attracted to uninfested leaves and flowers
of peabush. Moreover, they were also attracted to healthy and live virus-infected M. vitrata larvae, but not when the latter were moribund. Our data show that, similarly to what has been extensively been reported for
foliar volatiles, flowers of plants also emit parasitoid-attracting volatiles in response to being infested with an herbivore. 相似文献
2.
Developmental stage of herbivorePseudaletia separata affects production of herbivore-induced synomone by corn plants 总被引:1,自引:1,他引:1
J. Takabayashi S. Takahashi M. Dicke M. A. Posthumus 《Journal of chemical ecology》1995,21(3):273-287
The female parasitic waspCotesia kariyai discriminated between the volatiles of corn leaves infested by younger host larvaePseudaletia separata (first to fourth instar) and uninfested leaves in a Y-tube olfactometer; the wasps were attracted to the infested leaves. In contrast, when corn plants were infested by the later stages (fifth and sixth instar) of the armyworm, the wasps did not distinguish between infested corn leaves and uninfested corn leaves in the olfactometer. Mechanically damaged leaves were no more attractive than undamaged leaves, and host larvae or their feces were not attractive to the parasitoid. Through chemical analysis, the herbivore-induced plant volatiles were identified in the headspace of infested corn leaves. The herbivore-induced volatiles (HIVs) constituted a larger proportion of the headspace of corn leaves infested by early instar armyworms than of corn leaves infested by late instar armyworms. Application of third-instar larval regurgitant onto artificially damaged sites of leaves resulted in emission of parasitoid attractants from the leaf, whereas leaves treated with sixth-instar regurgitant did not. The function of this herbivore-stage related specificity of herbivore-induced synomones is discussed in a tritrophic context. 相似文献
3.
The origin of olfactory stimuli involved in the host microhabitat location inCotesia flavipes, a parasitoid of stem-borer larvae, was investigated in a Y-tube olfactometer. The response of femaleC. flavipes towards different components of the plant-host complex, consisting of a maize plant infested with two or more larvae of the stem borerChilo partellus, was tested in dualchoice tests. The concealed lifestyle of the stem-borer larvae did not limit the emission of volatiles attractive to a parasitoid. A major source of the attractive volatiles from the plant-host complex was the stem-borer-injured stem, including the frass produced by the feeding larvae. Moreover, the production of volatiles attractive to a parasitoid was not restricted to the infested stem part but occurs systemically throughout the plant. The uninfested leaves of a stem-borer-infested plant were found to emit volatiles that attract femaleC. flavipes. We further demonstrate that an exogenous elicitor of this systemic plant response is situated in the regurgitate of a stem-borer larva. When a minor amount of regurgitate is inoculated into the stem of an uninfested plant, the leaves of the treated plant emit volatiles that attract femaleC. flavipes. 相似文献
4.
Systemic release of herbivore-induced plant volatiles by turnips infested by concealed root-feeding larvae Delia radicum L 总被引:2,自引:0,他引:2
When attacked by herbivorous insects, many plants emit volatile compounds that are used as cues by predators and parasitoids foraging for prey or hosts. While such interactions have been demonstrated in several host–plant complexes, in most studies, the herbivores involved are leaf-feeding arthropods. We studied the long-range plant volatiles involved in host location in a system based on a very different interaction since the herbivore is a fly whose larvae feed on the roots of cole plants in the cabbage root fly, Delia radicum L. (Diptera: Anthomyiidae). The parasitoid studied is Trybliographa rapae Westwood (Hymenoptera: Figitidae), a specialist larval endoparasitoid of D. radicum. Using a four-arm olfactometer, the attraction of naive T. rapae females toward uninfested and infested turnip plants was investigated. T. rapae females were not attracted to volatiles emanating from uninfested plants, whether presented as whole plants, roots, or leaves. In contrast, they were highly attracted to volatiles emitted by roots infested with D. radicum larvae, by undamaged parts of infested roots, and by undamaged leaves of infested plants. The production of parasitoid-attracting volatiles appeared to be systemic in this particular tritrophic system. The possible factors triggering this volatile emission were also investigated. Volatiles from leaves of water-stressed plants and artificially damaged plants were not attractive to T. rapae females, while volatiles emitted by leaves of artificially damaged plants treated with crushed D. radicum larvae were highly attractive. However, T. rapae females were not attracted to volatiles emitted by artificially damaged plants treated only with crushed salivary glands from D. radicum larvae. These results demonstrate the systemic production of herbivore-induced volatiles in this host-plant complex. Although the emission of parasitoid attracting volatiles is induced by factors present in the herbivorous host, their exact origin remains unclear. The probable nature of the volatiles involved and the possible origin of the elicitor of volatiles release are discussed. 相似文献
5.
Xiao-Ling Sun Guo-Chang Wang Xiao-Ming Cai Shan Jin Yu Gao Zong-Mao Chen 《Journal of chemical ecology》2010,36(4):388-395
The tea weevil, Myllocerinus aurolineatus (Voss) (Coleoptera: Curculionidae), is a leaf-feeding pest of Camellia sinensis (O.Ktze.) with aggregative behaviors that can seriously reduce tea yield and quality. Although herbivore-induced host plant
volatiles have been shown to attract conspecific individuals of some beetle pests, especially members of the Chrysomelidae
family, little is known about the volatiles emitted from tea plants infested by M. aurolineatus adults and their roles in mediating interactions between conspecifics. The results of behavioral bioassays revealed that
volatile compounds emitted from tea plants infested by M. aurolineatus were attractive to conspecific weevils. Volatile analyses showed that infestations dramatically increased the emission of
volatiles, (Z)-3-hexenal, (Z)-3-hexenol, (E)-β-ocimene, linalool, phenylethyl alcohol, benzyl nitrile, indole, (E, E)-α-farnesene, (E)-nerolidol, and 31 other compounds. Among the induced volatiles, 12 chemicals, including γ-terpinene, benzyl alcohol, (Z)-3-hexenyl acetate, myrcene, benzaldehyde, (Z)-3-hexenal, and (E, E)-α-farnesene, elicited antennal responses from both sexes of the herbivore, whereas (E)-β-ocimene elicited antennal responses only from males. Using a Y-tube olfactometer, we found that six of the 13 chemicals,
γ-terpinene, benzyl alcohol, (Z)-3-hexenyl acetate, myrcene, benzaldehyde, and (Z)-3-hexenal, were attractive to both males and females; two chemicals, (E/Z)-β-ocimene and (E, E)-α-farnesene, were attractive only to males; and four chemicals, (E)-4,8-dimethyl-1,3,7-nonatriene, phenylethyl alcohol, linalool, and (Z)-3-hexenol, were attractive only to females. The findings
provide new insights into the interactions between tea plants and their herbivores, and may help scientists develop new strategies
for controlling the herbivore. 相似文献
6.
Takeshi Shimoda Junji Takabayashi Wataru Ashihara Akio Takafuji 《Journal of chemical ecology》1997,23(8):2033-2048
We studied the response of a predatory thrips, Scolothrips takahashii, towards herbivore-induced plant volatiles emitted by Lima bean plants infested by two-spotted spider mites Tetranychus urticae (green form). Tests were conducted with a Y-tube olfactometer in the laboratory and with traps under field conditions. The odor of artificially damaged and uninfested Lima bean leaves was not more attractive than clean air in the Y-tube olfactometer. The predatory insects showed a greater preference for Lima bean leaves infested by the two-spotted spider mites than for either clean air or uninfested bean leaves. They showed the same preference towards infested leaves from which all spider mites and their visible products had been removed. Neither the spider mites themselves nor their products attracted the predators. In a satsuma mandarin grove, two traps with infested Lima bean plants as an odor source attracted 42 adult S. takahashii in 55 days, whereas no S. takahashii were trapped in two control traps with uninfested Lima bean plants during the same period. No S. takahashii were found during this period in the vicinity of either the sample traps or the control traps (5-m radius of each trap). These data showed that S. takahashii use herbivore-induced plant volatiles in their foraging behavior in natural ecosystems. 相似文献
7.
Astrid Kännaste Henrik Nordenhem Göran Nordlander Anna-Karin Borg-Karlson 《Journal of chemical ecology》2009,35(10):1262-1271
Induced responses by Norway spruce (Picea abies) seedlings to feeding damage by two mite species were studied by analyzing the volatiles emitted during infestation. Four
specimens of a Norway spruce (Picea abies L.) clone were infested with mites of Nalepella sp., another four with Oligonychus ununguis, and four were kept mite-free as controls. After a year of infestation, spruce volatiles were collected, analyzed, and identified
using SPME-GC-MS. In addition, enantiomers of chiral limonene and linalool were separated by two-dimensional GC. Methyl salicylate
(MeSA), (-)-linalool, (E)-β-farnesene, and (E,E)-α-farnesene were the main volatiles induced by both species of mites, albeit in different proportions. The ability of the
main compounds emitted by the mite-infested spruces to attract or repel the pine weevil, Hylobius abietis (L.), was tested. (E)-β-farnesene was found to be attractive in the absence of spruce odor, whereas methyl salicylate had a deterrent effect in
combination with attractive spruce odor. The other tested compounds had no significant effects on the behavior of the weevils. 相似文献
8.
Effects of molasses grass,Melinis minutiflora volatiles on the foraging behavior of the cereal stemborer parasitoid,Cotesia sesamiae 总被引:1,自引:0,他引:1
Olfactory responses of the cereal stemborer parasitoid Cotesia
sesamiae to volatiles emitted by gramineous host and nonhost plants of the stemborers were studied in a Y-tube olfactometer. The host plants were maize (Zea mays) and sorghum ( Sorghum bicolor), while the nonhost plant was molasses grass (Melinis minutiflora). In single-choice tests, females of C. sesamiae chose volatiles from infested and uninfested host plants and molasses grass over volatiles from the control (soil). In dual-choice tests, the wasp preferred volatiles from infested host plants to those from uninfested host plants. There was no discrimination between molasses grass volatiles and those of uninfested maize, uninfested sorghum, or infested maize. The wasp preferred sorghum volatiles over maize. Combining uninfested maize or sorghum with molasses grass did not make volatiles from the combination more attractive as compared to only uninfested host plants. Infested maize alone was as attractive as when combined with molasses grass. Infested sorghum was preferred over its combination with molasses grass. Local growth conditions of the molasses grasses influenced attractiveness to the parasitoids. Volatiles from Thika molasses grass were attractive, while those from Mbita molasses grass were not. Growing the Thika molasses grass in Mbita rendered it unattractive and vice versa with the Mbita molasses grass. This is a case of the same genotype expressing different phenotypes due to environmental factors. 相似文献
9.
The effect of volatiles related to feeding activity of nonprey caterpillars, Spodoptera exigua, on the olfactory response of the predatory mites Phytoseiulus persimilis was examined in a Y-tube olfactometer. At a low caterpillar density (20 caterpillars on 10 Lima bean leaves), the predators were significantly more attracted to volatiles from infested leaves on which the caterpillars and their products were present or from infested leaves from which the caterpillars and their products had been removed when compared to volatiles from uninfested leaves. The predators, however, significantly avoided odors from 20 caterpillars and their products (mainly feces) removed from bean leaves. In contrast, at a higher caterpillar density (100 caterpillars on 10 Lima bean leaves), the predators avoided volatiles from caterpillar-infested bean leaves. Volatiles from infested leaves from which the caterpillars and their products had been removed were not preferred over volatiles from uninfested leaves. Volatiles from feces collected from 100 caterpillars were strongly avoided by the predators, while the behavior of the predatory mites was not affected by volatiles from 100 caterpillars removed from a plant. The data show that carnivorous arthropods may avoid nonprofitable herbivores. This avoidance seems to result from an interference of volatiles from herbivore products with the attraction to herbivore-induced plant volatiles. 相似文献
10.
Responses of Neoseiulus cucumeris (a predatory mite) and the predatory insect Orius strigicollis to volatiles associated with two different plant species infested with onion thrips, Thrips tabaci, were examined in a Y-tube olfactometer. Both predators species showed a significant preference for volatiles from infested
cucumber leaves without T. tabaci over clean air. However, they were not attracted to volatiles from uninfested cucumber leaves, artificially damaged cucumber
leaves, or volatiles from T. tabaci plus their visible products collected from cucumber leaves. These results suggest that both predator species are capable
of exploiting herbivore-induced volatiles from T. tabaci-infested cucumber leaves as a foraging cue. Neither predator was attracted to volatiles from uninfested spring onion leaves,
infested spring onion leaves without T. tabaci, or volatiles from T. tabaci plus their visible products collected from spring onion leaves. Interestingly, they avoided volatiles from artificially damaged
spring onion leaves. A possible explanation for the non-significant olfactory responses of the predator species to spring
onion plants with infestation damage of T. tabaci is discussed. 相似文献
11.
The chemical ecology of the leafhopper, Cicadulina storeyi China (Homoptera: Cicadellidae), an important vector of Maize Streak Virus (MSV), was studied with a view to developing novel
leafhopper control strategies in sub-Saharan Africa. Choice tests using a Y-tube olfactometer revealed that odors from uninfested
maize seedlings (Zea mays cv. Delprim) were significantly more attractive to C. storeyi than odors from C. storeyi-infested seedlings. Headspace samples of volatile organic compounds (VOCs) collected from 10 to 12 day-old uninfested seedlings
were more attractive than those collected from infested seedlings. While VOCs collected from uninfested maize seedlings were
attractive, VOCs collected from C. storeyi-infested seedlings were significantly repellent. Analysis of the collected VOCs by gas chromatography (GC) and coupled GC-mass
spectrometry (GC-MS) led to the identification of myrcene, linalool, (E)-2-decen-1-ol, and decanal from uninfested seedlings, and (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, benzyl acetate, indole, geranyl acetate, (E)-caryophyllene, α-bergamotene, (E)-β-farnesene, β-sesquiphellandrene, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT) from infested seedlings. Of these, methyl salicylate, (E)-caryophyllene, (E)-β-farnesene, and TMTT were identified previously as volatile semiochemicals involved in plant defense against other sucking
insect pests. When tested individually for behavioral activity, all compounds were repellent for C. storeyi. Moreover, when these induced VOCs were added to the blend of VOCs from uninfested maize seedlings, a shift from attraction
to repellency was observed. Addition of methyl salicylate, (E)-β-farnesene, or TMTT resulted in a choice for the solvent control (i.e., repulsion), whereas addition of (E)-caryophyllene resulted in no reduction in host VOC attractiveness. These results show that VOCs induced in maize have the
potential to be exploited in the control of viruliferous leafhoppers in sub-Saharan Africa. 相似文献
12.
Leaf age affects composition of herbivore-induced synomones and attraction of predatory mites 总被引:6,自引:0,他引:6
J. Takabayashi M. Dicke S. Takahashi M. A. Posthumus T. A. Van Beek 《Journal of chemical ecology》1994,20(2):373-386
We investigated the olfactory response of the predatory mitePhytoseiulus persimilis to cucumber leaves infested with prey, the herbivorous spider miteTetranychus urticae. The predators responded to volatiles from young rather than old infested cucumber leaves. GC-MS analysis of the head-space of spider mite-infested, artificially damaged and undamaged cucumber plants showed that herbivore-induced plant volatiles were present among the volatiles of both old and young infested cucumber leaves. The major components of the herbivore-induced plant volatiles were (3E)-4,8-dimethyl-1,3,7-nonatriene and (E)--ocimene: these compounds are known to attract the predatory mites. In addition, we found three oximes (2-methylbutanalO-methyloxime, 3-methylbutanalO-methyloxime, and an unknown oxime) in the headspace of both old and young infested cucumber leaves. 3-MethylbutanalO-methyloxime and the unknown oxime were much more abundant in the headspace of infested old cucumber leaves. The potential adaptive value of differential attractiveness of cucumber plant leaves of different age is discussed. 相似文献
13.
There is increasing evidence that volatiles emitted by herbivore-damaged plants can cause responses in downwind undamaged neighboring plants, such as the attraction of carnivorous enemies of herbivores. One of the open questions is whether this involves an active (production of volatiles) or passive (adsorption of volatiles) response of the uninfested downwind plant. This issue is addressed in the present study. Uninfested lima bean leaves that were exposed to volatiles from conspecific leaves infested with the spider mite Tetranychus urticae, emitted very similar blends of volatiles to those emitted from infested leaves themselves. Treating leaves with a protein-synthesis inhibitor prior to infesting them with spider mites completely suppressed the production of herbivore-induced volatiles in the infested leaves. Conversely, inhibitor treatment to uninfested leaves prior to exposure to volatiles from infested leaves did not affect the emission of volatiles from the exposed, uninfested leaves. This evidence supports the hypothesis that response of the exposed downwind plant is passive. T. urticae-infested leaves that had been previously exposed to volatiles from infested leaves emitted more herbivore-induced volatiles than T. urticae-infested leaves previously exposed to volatiles from uninfested leaves. The former leaves were also more attractive to the predatory mite, Phytoseiulus persimilis, than the latter. This shows that previous exposure of plants to volatiles from herbivore-infested neighbors results in a stronger response of plants in terms of predator attraction when herbivores damage the plant. This supports the hypothesis that the downwind uninfested plant is actively involved. Both adsorption and production of volatiles can mediate the attraction of carnivorous mites to plants that have been exposed to volatiles from infested neighbors. 相似文献
14.
Apple Fruit Infested with Codling Moth are More Attractive to Neonate Codling Moth Larvae and Possess Increased Amounts of (E,E)-α-Farnesene 总被引:1,自引:0,他引:1
Peter J. Landolt Jewel A. Brumley Connie L. Smithhisler Lisa L. Biddick Richard W. Hofstetter 《Journal of chemical ecology》2000,26(7):1685-1699
Apple fruit artificially infested with codling moth larvae attracted significantly more neonate larvae of the codling moth, Cydia pomonella than uninfested fruit. A greater number of larvae responded to odor in an olfactometer from codling moth-infested cold-stored Red Delicious thinning apples than uninfested apples. Immature Granny Smith, Red Delicious, or Golden Delicious apples that were infested on the tree for five days by codling moth larvae were more attractive to neonate codling moth larvae than similar but uninfested fruit of the same varieties. Apples infested on the tree and sampled five days later also contained significantly greater amounts of the larval attractant (E,E)--farnesene, compared to uninfested apples. Other types of injury to apple fruit did not produce results similar to that from codling moth infestation, either in increased attractiveness to codling moth larvae or in increased quantities of (E,E)--farnesene. These results are consistent with the reported attractiveness of (E,E)--farnesene to neonate codling moth larvae. 相似文献
15.
Induction of volatile emissions in maize by different larval instars of Spodoptera littoralis 总被引:5,自引:0,他引:5
Maize plants under attack by caterpillars emit a specific blend of volatiles that is highly attractive to parasitic wasps. The release of these signals is induced by elicitors in the caterpillar regurgitant. Studies suggest that plants respond differently to different herbivore species and even to different herbivore stages, thus providing parasitoids and predators with specific signals. We tested if this is the case for different larval instars of the noctuid moth Spodoptera littoralis when they feed on maize plants. Cut maize plants were incubated in diluted regurgitant from second, third, or fifth instar caterpillars. There were no differences in total amount released after these treatments, but there were small differences in the release of the minor compounds phenethyl acetate and -humulene. Regurgitant of all three instars contained the elicitor volicitin. To test the effect of actual feeding by the larvae, potted plants were infested with caterpillars of one of the three instars, and volatiles were collected the following day. The intensity of the emissions was correlated with the number of larvae feeding on a plant, and with the amount of damage inflicted, but was independent of the instar that caused the damage. We also used artificial damage to mimic the manner of feeding of each instar to test the importance of physical aspects of damages for the odor emission. The emission was highly variable, but no differences were found among the different types of damage. In olfactometer tests, Microplitis rufiventris, a parasitoid that can only successfully parasitize second and early third instar S. littoralis, did not differentiate among the odors of maize plants attacked by different instar larvae. The odor analyses as well as the parasitoid's responses indicate that maize odors induced by S. littoralis provide parasitoids with poor information on the larval developmental stage. We discuss the results in the context of variability and lack of specificity in odorous plant signals. 相似文献
16.
We compared the chemical compositions of the osmeterial secretions of fourth and fifth (last) instars of eight swallowtail species of the tribe Papilionini. Four species (Papilio demoleus, P. polytes, P. paris, and P. macilentus) are Asian Rutaceae-feeding swallowtails. The other four (Chilasa epicydes, C. agestor, P. troilus, and P. glaucus) represent more distant clades within the Papilionini and species with larval hosts in other plant families. We conducted a quantitative analysis for six species, but only qualitative analysis for P. glaucus and C. agestor. In all eight species, regardless of larval host plant, secretions of the fourth instar principally consisted of mono- and sesquiterpene hydrocarbons, whereas those of the fifth instar comprised aliphatic acids and their esters. Consistent with earlier findings, our results suggest that this “heterogeneous” pattern of osmeterial chemistry, not seen in other tribes, may characterize the Papilionini as a whole. Unlike those of most Papilio species, the fourth and fifth instars of Chilasa species resemble each other in body coloration. Thus, the heterogeneous osmeterial pattern is not necessarily associated with color change in papilionid larvae. The major terpenoids identified in fourth instar larval secretions from the six species were α-pinene, sabinene, β-myrcene, limonene, β-phellandrene, (Z)-β-ocimene, (E)-β-ocimene, p-mentha-1,4(8)-diene, β-elemene, β-caryophyllene, (E)-β-farnesene, (3Z,6E)-α-farnesene, (Z)-α-bisabolene, germacrene-A, (E)-α-bisabolene, and germacrene-B. The profiles for individual species differed both qualitatively and quantitatively from one another, and certain species also secreted methyl 3-hydroxy-n-butyrate and oxygenated sesquiterpenes in relatively large proportions. Secretions from fifth instars were composed of varying proportions of isobutyric, 2-methylbutyric, and acetic acids, and methyl and ethyl (minor) esters of both isobutyric and 2-methylbutyric acids. The heterogeneity of osmeterial chemistry in the tribe Papilionini may represent fine-tuning of chemical defense in response to shifting predation pressures as the larvae age and grow. 相似文献
17.
In response to herbivory by spider mites (Tetranychus urticae), lima bean plants produced significantly greater quantities of extrafloral nectar (EFN) than intact conspecific plants. Moreover, EFN amounts of infested plants depended on exposure to odor of infested neighbor plants. Two d after spider mite infestation, a test plant produced more EFN when exposed prior to infestation to volatiles from infested neighbor plants than when exposed to volatiles from uninfested conspecific plants. However, this effect was only detectable 2 d after spider mite infestation and vanished 4 d after infestation. These results suggest that EFN production is enhanced during the earlier stages of damage by T. urticae in response to previous exposure to volatiles from infested neighbor plants. 相似文献
18.
Iris F. Kappers Francel W. A. Verstappen Ludo L. P. Luckerhoff Harro J. Bouwmeester Marcel Dicke 《Journal of chemical ecology》2010,36(5):500-512
Cucumber plants (Cucumis sativus L.) respond to spider–mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites,
to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid.
We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid
using gas chromatography—mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend
of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with
jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-α-farnesene, and (E)-β-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions
was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and
displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds
within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number
of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated
to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant
volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory
mites and other biological control agents. 相似文献
19.
We investigated volatile infochemicals possibly involved in location of the generalist predatory mite Neoseiulus californicus to plants infested with spider mites in a Y-tube olfactometer. The predators significantly preferred volatiles from lima bean leaves infested with Tetranychus urticae to uninfested lima bean leaves. Likewise, they were attracted to volatiles from artificially damaged lima bean leaves and those from T. urticae plus their visible products. Significantly more predators chose infested lima bean leaves from which T. urticae plus their visible products had been removed than artificially damaged leaves, T. urticae, and their visible products. These results suggest that N. californicus is capable of exploiting a variety of volatile infochemicals originating from their prey, from the prey-foodplants themselves, and from the complex of the prey and the host plants (e.g., herbivore-induced volatiles). We also investigated predator response to some of the synthetic samples identified as volatile components emitted from T. urticae-infested lima bean leaves and/or artificially damaged lima bean leaves. The predators were attracted to each of the five synthetic volatile components: linalool, methyl salicylate, (Z)-3-hexen-1-ol, (E)-2-hexenal, and (Z)-3-hexenyl acetate. The role of each volatile compound in prey-searching behavior is discussed. 相似文献
20.
During development of figs on Ficus hispida, only the female floral stage is receptive to its pollinator Ceratosolen solmsi marchali. After this stage, the quantity of fig odor decreases. The effects of F. hispida volatiles from receptive figs (figs at the female floral stage, when they are pollinated) and interfloral figs (between the
female floral and male floral stages) on their pollinator were studied, together with responses to compounds present in the
odor. Odors emitted by both receptive and interfloral figs were attractive to the pollinator. However, wasps preferred the
odor of receptive figs to that of interfloral figs even though the quantity of interfloral volatiles increased. Three monoterpenes
that included linalool (major constitutent) and two minor compounds limonene and β-pinene from the receptive fig volatiles
were used to test the pollinator responses. The levoisomer and racemic mixtures of linalool were attractive to the pollinator
at high doses, but the dextroisomer was neutral. (±)-Limonene and (−)-β-pinene at high doses were even less attractive to
the pollinator than clean air and were neutral at low doses, while (R)-(+)-, (S)-(−)-limonene were neutral at all doses. In blend tests, all four mixtures of (±)-linalool or (S)-(−)-linalool combined with (±)-limonene or (−)-β-pinene attracted C. solmsi marchali when administered at high doses. (R)-(+)-linalool and (−)-β-pinene enhanced the attractiveness of (S)-(−)-linalool to the pollinator, while enantiomers of limonene did not. These results suggest that both quality and quantity
of fig volatiles regulate C. solmsi marchali response and that quality is the main host-finding and floral stage-distinguishing cue for the pollinator. Synergistic effects
of some compounds may play a role in enhancing attractiveness of the active compounds. 相似文献