The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
Bruce W. Zilkowski - One of the best experts on this subject based on the ideXlab platform.
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similarities in pheromonal communication of flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Journal of Applied Entomology, 2012Co-Authors: Miklós Tóth, Eva Balintne Csonka, Allard A. Cossé, Robert J. Bartelt, Bruce W. ZilkowskiAbstract:Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male-produced sesquiterpene identified from North American Ph. cruciferae [compound A, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0]undeca-1(11),9-diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3-butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3-butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host-derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.
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pheromonal activity of compounds identified from male Phyllotreta cruciferae field tests of racemic mixtures pure enantiomers and combinations with allyl isothiocyanate
Journal of Chemical Ecology, 2005Co-Authors: Miklós Tóth, Eva Balintne Csonka, Bruce W. Zilkowski, Allard A. Cossé, Robert J. Bartelt, Shin Etsu Muto, Kenji MoriAbstract:Four himachalene sesquiterpenes and (+)-γ-cadinene, previously identified as possible pheromone components from males of a North American population of Phyllotreta cruciferae Goeze (Coleoptera, Chrysomelidae), were tested for attractiveness in field trapping experiments in Hungary. A mixture of the four synthetic racemic himachalene derivatives and (+)-γ-cadinene from a botanical source was slightly attractive to beetles, but much more attractive when blended with the known host-plant-derived attractant allyl isothiocyanate. This result was consistent with a previous study in North America. In tests with optically pure synthetic compounds, a blend of the same himachalene enantiomers found from male beetles was equivalent to the corresponding blend of racemic compounds, whereas a blend of the opposite enantiomers was not active. Through subtraction tests, it was found that the single compound, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0.]undeca-9,11-diene [compound (+)-A in this study], was as active as the whole mixture, suggesting that this compound is the key pheromone component of the European population of P. cruciferae. During field trials, several congeneric species, including P. vittula, P. nemorum, P. nodicornis, and P. ochripes, also were caught, suggesting that the same compound(s) may be relatively widespread as pheromone components in this genus.
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responses of flea beetle Phyllotreta cruciferae to synthetic aggregation pheromone components and host plant volatiles in field trials
Journal of Chemical Ecology, 2005Co-Authors: Juliana J. Soroka, Bruce W. Zilkowski, Robert J. Bartelt, Allard A. CosséAbstract:Male-specific compounds, previously identified from Phyllotreta cruciferae and synthesized or isolated from natural sources, attracted both sexes of the beetle in field trials and therefore function as components of a male-produced aggregation pheromone. Six field experiments of 7 to 10 d duration each were conducted over 2 yr using modified boll weevil traps and two doses of pheromone. Treatments containing two doses of allyl isothiocyanate (AITC), a breakdown product of glucosinolates in Brassica napus L., a host plant of the beetles, were included in the study. A dose response was observed for both the pheromone components and AITC, and combinations of the pheromone and AITC generally attracted greater numbers of flea beetles than did either component itself. This increased attraction to a combination of beetle-produced compounds and host odors has not been previously demonstrated in halticine beetles and could help explain patterns of movement by P. cruciferae into field crops.
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male specific sesquiterpenes from Phyllotreta and aphthona flea beetles
Journal of Chemical Ecology, 2001Co-Authors: Robert J. Bartelt, Bruce W. Zilkowski, Allard A. Cossé, David Weisleder, Frank A. MomanyAbstract:It was previously reported that males of the crucifer flea beetle, Phyllotreta cruciferae, feeding on host foliage are attractive to both males and females in the field. Based on this evidence for an aggregation pheromone, volatiles were collected from male and female P. cruciferae feeding on cabbage (Brassica oleracea) and analyzed. For comparison, volatiles were also collected from males and females of three other flea beetle species, Aphthona flava,A. czwalinae, and A. cyparissiae, all feeding on their host, leafy spurge foliage (Euphorbia esula). Six male-specific compounds were isolated from P. cruciferae, and the same compounds plus two additional ones were isolated from males of Aphthona flava,A. czwalinae, and A. cyparissiae. The blends of compounds were relatively consistent within species, but there were characteristic differences between species. Compound structures were studied by mass spectrometry, NMR spectroscopy, UV spectroscopy, polarimetry, chiral and achiral gas chromatography, molecular modeling, and microchemical tests. Three of the compounds were identified as (+)-ar-himachalene; (+)-trans-α-himachalene; (+)-γ-cadinene. Two others were new enantiomers of himachalene hydrocarbons that were previously identified from the fir trees, Abies alba and Abies nordmanniana. Finally, there were two himachalene alcohols and one norsesquiterpene ketone that is a himachalene analog. Only (+)-ar-himachalene and (+)-γ-cadinene are previously known natural products. Electrophysiological activity was demonstrated for five of the compounds. The chemical and electrophysiological patterns are consistent with, but do not prove, a pheromonal function.
Miklós Tóth - One of the best experts on this subject based on the ideXlab platform.
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similarities in pheromonal communication of flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Journal of Applied Entomology, 2012Co-Authors: Miklós Tóth, Eva Balintne Csonka, Allard A. Cossé, Robert J. Bartelt, Bruce W. ZilkowskiAbstract:Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male-produced sesquiterpene identified from North American Ph. cruciferae [compound A, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0]undeca-1(11),9-diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3-butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3-butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host-derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.
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differences in host plant related chemical communication of the flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Acta Phytopathologica Et Entomologica Hungarica, 2007Co-Authors: Eva Balintne Csonka, Miklós Tóth, István UjváryAbstract:Remarkable differences have been found in host-plant related chemical communication between Phyllotreta cruciferae Goeze and Ph. vittula Redtenbacher (Coleoptera, Chrysomelidae). In preliminary screenings sizeable catches of Ph. vittula were recorded in traps baited with either 3-butenyl isothiocyanate, or a quternary mixture of 2-butenyl-, phenethyl-, 3-butenyl-and butyl isothiocyanates. Later studies revealed that Ph. vittula responded better to the above isothiocyanate mixture, than to allyl isothiocyanate, while Ph. cruciferae catches were always greater in allyl isothiocyanate baited traps. Of the four isothiocyanates in the mixture, 3-butenyl isothiocyanate may predominantly be responsible for attractivity of the mixture towards Ph. vittula .As such differences in isothiocyanate preference may occur also in other flea beetle species, for practical applications more efficient, selective and sensitive baits and traps may be developed in the future based on improved knowledge of the chemical communicat...
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species spectrum of flea beetles Phyllotreta spp coleoptera chrysomelidae attracted to allyl isothiocyanate baited traps
Zeitschrift für Naturforschung C, 2007Co-Authors: Miklós Tóth, Eva Balintne Csonka, Florian Bakcsa, Pal Benedek, Istvan Szarukan, Stanislav Gomboc, Teodora B Toshova, Mitko Subchev, István UjváryAbstract:: In field tests in Hungary, Slovenia and Bulgaria, in allyl isothiocyanate-baited traps significantly more beetles of Phyllotreta cruciferae, Ph. vittula, Ph. undulata, Ph. nigripes, Ph. nodicornis, Ph. balcanica, Ph. atra, Ph. procera, Ph. ochripes, Ph. diademata and Psylliodes chrysocephalus (Coleoptera, Chrysomelidae, Halticinae) were captured than in unbaited control traps. With the exception of Ph. cruciferae, this is the first report on significant field attraction by allyl isothiocyanate for these species. The species spectrum captured included six important agricultural pests. At all sites a great portion of the catch (ranging from ca 30 to 98%) was Ph. cruciferae, irrespective of the plant culture. The second most abundant species present at most sites was Ph. vittula. The present results are very promising from the point of view of applicability of allyl isothiocyanate in Europe as a bait in cabbage flea beetle traps for detection and monitoring.
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pheromonal activity of compounds identified from male Phyllotreta cruciferae field tests of racemic mixtures pure enantiomers and combinations with allyl isothiocyanate
Journal of Chemical Ecology, 2005Co-Authors: Miklós Tóth, Eva Balintne Csonka, Bruce W. Zilkowski, Allard A. Cossé, Robert J. Bartelt, Shin Etsu Muto, Kenji MoriAbstract:Four himachalene sesquiterpenes and (+)-γ-cadinene, previously identified as possible pheromone components from males of a North American population of Phyllotreta cruciferae Goeze (Coleoptera, Chrysomelidae), were tested for attractiveness in field trapping experiments in Hungary. A mixture of the four synthetic racemic himachalene derivatives and (+)-γ-cadinene from a botanical source was slightly attractive to beetles, but much more attractive when blended with the known host-plant-derived attractant allyl isothiocyanate. This result was consistent with a previous study in North America. In tests with optically pure synthetic compounds, a blend of the same himachalene enantiomers found from male beetles was equivalent to the corresponding blend of racemic compounds, whereas a blend of the opposite enantiomers was not active. Through subtraction tests, it was found that the single compound, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0.]undeca-9,11-diene [compound (+)-A in this study], was as active as the whole mixture, suggesting that this compound is the key pheromone component of the European population of P. cruciferae. During field trials, several congeneric species, including P. vittula, P. nemorum, P. nodicornis, and P. ochripes, also were caught, suggesting that the same compound(s) may be relatively widespread as pheromone components in this genus.
Eva Balintne Csonka - One of the best experts on this subject based on the ideXlab platform.
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similarities in pheromonal communication of flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Journal of Applied Entomology, 2012Co-Authors: Miklós Tóth, Eva Balintne Csonka, Allard A. Cossé, Robert J. Bartelt, Bruce W. ZilkowskiAbstract:Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male-produced sesquiterpene identified from North American Ph. cruciferae [compound A, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0]undeca-1(11),9-diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3-butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3-butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host-derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.
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differences in host plant related chemical communication of the flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Acta Phytopathologica Et Entomologica Hungarica, 2007Co-Authors: Eva Balintne Csonka, Miklós Tóth, István UjváryAbstract:Remarkable differences have been found in host-plant related chemical communication between Phyllotreta cruciferae Goeze and Ph. vittula Redtenbacher (Coleoptera, Chrysomelidae). In preliminary screenings sizeable catches of Ph. vittula were recorded in traps baited with either 3-butenyl isothiocyanate, or a quternary mixture of 2-butenyl-, phenethyl-, 3-butenyl-and butyl isothiocyanates. Later studies revealed that Ph. vittula responded better to the above isothiocyanate mixture, than to allyl isothiocyanate, while Ph. cruciferae catches were always greater in allyl isothiocyanate baited traps. Of the four isothiocyanates in the mixture, 3-butenyl isothiocyanate may predominantly be responsible for attractivity of the mixture towards Ph. vittula .As such differences in isothiocyanate preference may occur also in other flea beetle species, for practical applications more efficient, selective and sensitive baits and traps may be developed in the future based on improved knowledge of the chemical communicat...
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species spectrum of flea beetles Phyllotreta spp coleoptera chrysomelidae attracted to allyl isothiocyanate baited traps
Zeitschrift für Naturforschung C, 2007Co-Authors: Miklós Tóth, Eva Balintne Csonka, Florian Bakcsa, Pal Benedek, Istvan Szarukan, Stanislav Gomboc, Teodora B Toshova, Mitko Subchev, István UjváryAbstract:: In field tests in Hungary, Slovenia and Bulgaria, in allyl isothiocyanate-baited traps significantly more beetles of Phyllotreta cruciferae, Ph. vittula, Ph. undulata, Ph. nigripes, Ph. nodicornis, Ph. balcanica, Ph. atra, Ph. procera, Ph. ochripes, Ph. diademata and Psylliodes chrysocephalus (Coleoptera, Chrysomelidae, Halticinae) were captured than in unbaited control traps. With the exception of Ph. cruciferae, this is the first report on significant field attraction by allyl isothiocyanate for these species. The species spectrum captured included six important agricultural pests. At all sites a great portion of the catch (ranging from ca 30 to 98%) was Ph. cruciferae, irrespective of the plant culture. The second most abundant species present at most sites was Ph. vittula. The present results are very promising from the point of view of applicability of allyl isothiocyanate in Europe as a bait in cabbage flea beetle traps for detection and monitoring.
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pheromonal activity of compounds identified from male Phyllotreta cruciferae field tests of racemic mixtures pure enantiomers and combinations with allyl isothiocyanate
Journal of Chemical Ecology, 2005Co-Authors: Miklós Tóth, Eva Balintne Csonka, Bruce W. Zilkowski, Allard A. Cossé, Robert J. Bartelt, Shin Etsu Muto, Kenji MoriAbstract:Four himachalene sesquiterpenes and (+)-γ-cadinene, previously identified as possible pheromone components from males of a North American population of Phyllotreta cruciferae Goeze (Coleoptera, Chrysomelidae), were tested for attractiveness in field trapping experiments in Hungary. A mixture of the four synthetic racemic himachalene derivatives and (+)-γ-cadinene from a botanical source was slightly attractive to beetles, but much more attractive when blended with the known host-plant-derived attractant allyl isothiocyanate. This result was consistent with a previous study in North America. In tests with optically pure synthetic compounds, a blend of the same himachalene enantiomers found from male beetles was equivalent to the corresponding blend of racemic compounds, whereas a blend of the opposite enantiomers was not active. Through subtraction tests, it was found that the single compound, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0.]undeca-9,11-diene [compound (+)-A in this study], was as active as the whole mixture, suggesting that this compound is the key pheromone component of the European population of P. cruciferae. During field trials, several congeneric species, including P. vittula, P. nemorum, P. nodicornis, and P. ochripes, also were caught, suggesting that the same compound(s) may be relatively widespread as pheromone components in this genus.
Allard A. Cossé - One of the best experts on this subject based on the ideXlab platform.
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similarities in pheromonal communication of flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Journal of Applied Entomology, 2012Co-Authors: Miklós Tóth, Eva Balintne Csonka, Allard A. Cossé, Robert J. Bartelt, Bruce W. ZilkowskiAbstract:Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male-produced sesquiterpene identified from North American Ph. cruciferae [compound A, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0]undeca-1(11),9-diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3-butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3-butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host-derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.
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pheromonal activity of compounds identified from male Phyllotreta cruciferae field tests of racemic mixtures pure enantiomers and combinations with allyl isothiocyanate
Journal of Chemical Ecology, 2005Co-Authors: Miklós Tóth, Eva Balintne Csonka, Bruce W. Zilkowski, Allard A. Cossé, Robert J. Bartelt, Shin Etsu Muto, Kenji MoriAbstract:Four himachalene sesquiterpenes and (+)-γ-cadinene, previously identified as possible pheromone components from males of a North American population of Phyllotreta cruciferae Goeze (Coleoptera, Chrysomelidae), were tested for attractiveness in field trapping experiments in Hungary. A mixture of the four synthetic racemic himachalene derivatives and (+)-γ-cadinene from a botanical source was slightly attractive to beetles, but much more attractive when blended with the known host-plant-derived attractant allyl isothiocyanate. This result was consistent with a previous study in North America. In tests with optically pure synthetic compounds, a blend of the same himachalene enantiomers found from male beetles was equivalent to the corresponding blend of racemic compounds, whereas a blend of the opposite enantiomers was not active. Through subtraction tests, it was found that the single compound, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0.]undeca-9,11-diene [compound (+)-A in this study], was as active as the whole mixture, suggesting that this compound is the key pheromone component of the European population of P. cruciferae. During field trials, several congeneric species, including P. vittula, P. nemorum, P. nodicornis, and P. ochripes, also were caught, suggesting that the same compound(s) may be relatively widespread as pheromone components in this genus.
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responses of flea beetle Phyllotreta cruciferae to synthetic aggregation pheromone components and host plant volatiles in field trials
Journal of Chemical Ecology, 2005Co-Authors: Juliana J. Soroka, Bruce W. Zilkowski, Robert J. Bartelt, Allard A. CosséAbstract:Male-specific compounds, previously identified from Phyllotreta cruciferae and synthesized or isolated from natural sources, attracted both sexes of the beetle in field trials and therefore function as components of a male-produced aggregation pheromone. Six field experiments of 7 to 10 d duration each were conducted over 2 yr using modified boll weevil traps and two doses of pheromone. Treatments containing two doses of allyl isothiocyanate (AITC), a breakdown product of glucosinolates in Brassica napus L., a host plant of the beetles, were included in the study. A dose response was observed for both the pheromone components and AITC, and combinations of the pheromone and AITC generally attracted greater numbers of flea beetles than did either component itself. This increased attraction to a combination of beetle-produced compounds and host odors has not been previously demonstrated in halticine beetles and could help explain patterns of movement by P. cruciferae into field crops.
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male specific sesquiterpenes from Phyllotreta and aphthona flea beetles
Journal of Chemical Ecology, 2001Co-Authors: Robert J. Bartelt, Bruce W. Zilkowski, Allard A. Cossé, David Weisleder, Frank A. MomanyAbstract:It was previously reported that males of the crucifer flea beetle, Phyllotreta cruciferae, feeding on host foliage are attractive to both males and females in the field. Based on this evidence for an aggregation pheromone, volatiles were collected from male and female P. cruciferae feeding on cabbage (Brassica oleracea) and analyzed. For comparison, volatiles were also collected from males and females of three other flea beetle species, Aphthona flava,A. czwalinae, and A. cyparissiae, all feeding on their host, leafy spurge foliage (Euphorbia esula). Six male-specific compounds were isolated from P. cruciferae, and the same compounds plus two additional ones were isolated from males of Aphthona flava,A. czwalinae, and A. cyparissiae. The blends of compounds were relatively consistent within species, but there were characteristic differences between species. Compound structures were studied by mass spectrometry, NMR spectroscopy, UV spectroscopy, polarimetry, chiral and achiral gas chromatography, molecular modeling, and microchemical tests. Three of the compounds were identified as (+)-ar-himachalene; (+)-trans-α-himachalene; (+)-γ-cadinene. Two others were new enantiomers of himachalene hydrocarbons that were previously identified from the fir trees, Abies alba and Abies nordmanniana. Finally, there were two himachalene alcohols and one norsesquiterpene ketone that is a himachalene analog. Only (+)-ar-himachalene and (+)-γ-cadinene are previously known natural products. Electrophysiological activity was demonstrated for five of the compounds. The chemical and electrophysiological patterns are consistent with, but do not prove, a pheromonal function.
Robert J. Bartelt - One of the best experts on this subject based on the ideXlab platform.
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similarities in pheromonal communication of flea beetles Phyllotreta cruciferae goeze and ph vittula redtenbacher coleoptera chrysomelidae
Journal of Applied Entomology, 2012Co-Authors: Miklós Tóth, Eva Balintne Csonka, Allard A. Cossé, Robert J. Bartelt, Bruce W. ZilkowskiAbstract:Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male-produced sesquiterpene identified from North American Ph. cruciferae [compound A, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0]undeca-1(11),9-diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3-butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3-butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host-derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.
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pheromonal activity of compounds identified from male Phyllotreta cruciferae field tests of racemic mixtures pure enantiomers and combinations with allyl isothiocyanate
Journal of Chemical Ecology, 2005Co-Authors: Miklós Tóth, Eva Balintne Csonka, Bruce W. Zilkowski, Allard A. Cossé, Robert J. Bartelt, Shin Etsu Muto, Kenji MoriAbstract:Four himachalene sesquiterpenes and (+)-γ-cadinene, previously identified as possible pheromone components from males of a North American population of Phyllotreta cruciferae Goeze (Coleoptera, Chrysomelidae), were tested for attractiveness in field trapping experiments in Hungary. A mixture of the four synthetic racemic himachalene derivatives and (+)-γ-cadinene from a botanical source was slightly attractive to beetles, but much more attractive when blended with the known host-plant-derived attractant allyl isothiocyanate. This result was consistent with a previous study in North America. In tests with optically pure synthetic compounds, a blend of the same himachalene enantiomers found from male beetles was equivalent to the corresponding blend of racemic compounds, whereas a blend of the opposite enantiomers was not active. Through subtraction tests, it was found that the single compound, (6R,7S)-2,2,6,10-tetramethylbicyclo[5.4.0.]undeca-9,11-diene [compound (+)-A in this study], was as active as the whole mixture, suggesting that this compound is the key pheromone component of the European population of P. cruciferae. During field trials, several congeneric species, including P. vittula, P. nemorum, P. nodicornis, and P. ochripes, also were caught, suggesting that the same compound(s) may be relatively widespread as pheromone components in this genus.
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responses of flea beetle Phyllotreta cruciferae to synthetic aggregation pheromone components and host plant volatiles in field trials
Journal of Chemical Ecology, 2005Co-Authors: Juliana J. Soroka, Bruce W. Zilkowski, Robert J. Bartelt, Allard A. CosséAbstract:Male-specific compounds, previously identified from Phyllotreta cruciferae and synthesized or isolated from natural sources, attracted both sexes of the beetle in field trials and therefore function as components of a male-produced aggregation pheromone. Six field experiments of 7 to 10 d duration each were conducted over 2 yr using modified boll weevil traps and two doses of pheromone. Treatments containing two doses of allyl isothiocyanate (AITC), a breakdown product of glucosinolates in Brassica napus L., a host plant of the beetles, were included in the study. A dose response was observed for both the pheromone components and AITC, and combinations of the pheromone and AITC generally attracted greater numbers of flea beetles than did either component itself. This increased attraction to a combination of beetle-produced compounds and host odors has not been previously demonstrated in halticine beetles and could help explain patterns of movement by P. cruciferae into field crops.
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male specific sesquiterpenes from Phyllotreta and aphthona flea beetles
Journal of Chemical Ecology, 2001Co-Authors: Robert J. Bartelt, Bruce W. Zilkowski, Allard A. Cossé, David Weisleder, Frank A. MomanyAbstract:It was previously reported that males of the crucifer flea beetle, Phyllotreta cruciferae, feeding on host foliage are attractive to both males and females in the field. Based on this evidence for an aggregation pheromone, volatiles were collected from male and female P. cruciferae feeding on cabbage (Brassica oleracea) and analyzed. For comparison, volatiles were also collected from males and females of three other flea beetle species, Aphthona flava,A. czwalinae, and A. cyparissiae, all feeding on their host, leafy spurge foliage (Euphorbia esula). Six male-specific compounds were isolated from P. cruciferae, and the same compounds plus two additional ones were isolated from males of Aphthona flava,A. czwalinae, and A. cyparissiae. The blends of compounds were relatively consistent within species, but there were characteristic differences between species. Compound structures were studied by mass spectrometry, NMR spectroscopy, UV spectroscopy, polarimetry, chiral and achiral gas chromatography, molecular modeling, and microchemical tests. Three of the compounds were identified as (+)-ar-himachalene; (+)-trans-α-himachalene; (+)-γ-cadinene. Two others were new enantiomers of himachalene hydrocarbons that were previously identified from the fir trees, Abies alba and Abies nordmanniana. Finally, there were two himachalene alcohols and one norsesquiterpene ketone that is a himachalene analog. Only (+)-ar-himachalene and (+)-γ-cadinene are previously known natural products. Electrophysiological activity was demonstrated for five of the compounds. The chemical and electrophysiological patterns are consistent with, but do not prove, a pheromonal function.