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Christopher A Mullin - One of the best experts on this subject based on the ideXlab platform.
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Antifeedant Effects of Proteinase Inhibitors on Feeding Behaviors of Adult Western Corn Rootworm (Diabrotica virgifera virgifera)
Journal of Chemical Ecology, 2003Co-Authors: Jae Hak Kim, Christopher A MullinAbstract:Low-molecular-weight peptidyl proteinase inhibitors (PIs) including leupeptin, calpain inhibitor I, and calpeptin were found to be potent Antifeedants for adult western corn rootworm (WCR) against the phagostimulation of cucurbitacin B (Cuc B) or a corn pollen extract (CPE). Leupeptin was the strongest (ED_50 = 0.36 and 0.55 nmol/disk for Cuc B and CPE, respectively) among PIs tested with an antifeedant potency much stronger than the steroid progesterone (ED_50 = 2.29 and 5.05 nmol/disk for Cuc B and CPE, respectively), but slightly less than the reference alkaloid, strychnine (ED_50 = 0.17 and 0.37 nmol/disk for Cuc B and CPE, respectively). All active PIs contain a di- or tripeptidyl aldehyde moiety, indicating that PIs exert their antifeedant effects by covalent interaction with putative sulfhydryl (SH) groups on taste receptors as do these PIs with cysteine proteinases. However, opposite inhibition potency against Cuc B versus CPE by two thiol-group reducing agents, DTT and L-cysteine, and the results with other cysteine-modifying reagents obscure the net functional role of SH groups at WCR taste chemoreceptors. Surprisingly, the model phagostimulant for diabroticites, Cuc B, was more easily counteracted by these feeding deterrents than the stimulants present in CPE. Three-dimensional structure–antifeedant relationships for the PIs suggest that a novel taste chemoreception mechanism exists for these peptidyl aldehydes or that they fit partially into a strychnine binding pocket on protein chemoreceptors. Favorable economic benefit may be achieved if PIs are discovered to be useful in adult WCR control, since both pre- and postingestive sites would be targeted.
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Antifeedant Effects of Proteinase Inhibitors on Feeding Behaviors of Adult Western Corn Rootworm (Diabrotica virgifera virgifera)
Journal of Chemical Ecology, 2003Co-Authors: Christopher A MullinAbstract:Low-molecular-weight peptidyl proteinase inhibitors (PIs) including leupeptin, calpain inhibitor I, and calpeptin were found to be potent Antifeedants for adult western corn rootworm (WCR) against the phagostimulation of cucurbitacin B (Cuc B) or a corn pollen extract (CPE). Leupeptin was the strongest (ED_50 = 0.36 and 0.55 nmol/disk for Cuc B and CPE, respectively) among PIs tested with an antifeedant potency much stronger than the steroid progesterone (ED_50 = 2.29 and 5.05 nmol/disk for Cuc B and CPE, respectively), but slightly less than the reference alkaloid, strychnine (ED_50 = 0.17 and 0.37 nmol/disk for Cuc B and CPE, respectively). All active PIs contain a di- or tripeptidyl aldehyde moiety, indicating that PIs exert their antifeedant effects by covalent interaction with putative sulfhydryl (SH) groups on taste receptors as do these PIs with cysteine proteinases. However, opposite inhibition potency against Cuc B versus CPE by two thiol-group reducing agents, DTT and L-cysteine, and the results with other cysteine-modifying reagents obscure the net functional role of SH groups at WCR taste chemoreceptors. Surprisingly, the model phagostimulant for diabroticites, Cuc B, was more easily counteracted by these feeding deterrents than the stimulants present in CPE. Three-dimensional structure–antifeedant relationships for the PIs suggest that a novel taste chemoreception mechanism exists for these peptidyl aldehydes or that they fit partially into a strychnine binding pocket on protein chemoreceptors. Favorable economic benefit may be achieved if PIs are discovered to be useful in adult WCR control, since both pre- and postingestive sites would be targeted.
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antifeedant comparisons of gaba glycinergic antagonists for diabroticite leaf beetles coleoptera chrysomelidae
Journal of Chemical Ecology, 1997Co-Authors: Herbert Eichenseer, Christopher A MullinAbstract:The phagostimulatory sensitivity of diabroticite (Coleoptera, Chrysomelidae, Galerucinae) species to cucurbitacins is not correlated with Cucurbitaceae specialization, indicating that other factors, including the absence of feeding deterrents, may influence host–plant affinities among these beetles. Quinoline, indole, and isoquinoline alkaloids and sesquiterpene lactones believed to antagonize γ-aminobutyric acid/glycine Cl− ionophores mediating chemoreception were tested on squash blossom disks for antifeedant activity to four diabroticite species with different host plant specializations. Most alkaloids were antifeedant below 30 nmol/disk. Antifeedant concentrations of sesquiterpene lactones were higher than alkaloids for all species. Oligophagous Diabrotica virgifera virgifera was more sensitive to quinoline alkaloids than polyphagous D. undecimpuntata howardi. Diabrotica virgifera virgifera was also more sensitive to the indole alkaloids strychnine, brucine, eburnamonine, and vincamine than D. u. howardi. The closely related D. barberi had sensitivities similar to those of D. v. virgifera but the more distantly related Acalymma vittatum was less sensitive to the Antifeedants than D. v. virgifera The isoquinoline alkaloid hydrastine was uniformly antifeedant to all diabroticites. All the GABA/glycine neurotoxicams tested against diabroticites were feeding deterrents and suggest that beetles share a common antifeedant mechanism.
Azucena González-coloma - One of the best experts on this subject based on the ideXlab platform.
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Biocidal effects of Piper hispidinervum (Piperaceae) essential oil and synergism among its main components.
Food and Chemical Toxicology, 2017Co-Authors: Mª Fé Andrés, Rubem Mário Figueiró Vargas, Guilherme Evaldt Rossa, Eduardo Cassel, Omar Santana, Carmen E Diaz, Azucena González-colomaAbstract:Abstract In this study we evaluated the effect of a pressure gradient (1–2 atm) in the extraction and composition of the essential oil (EO) of Piper hispidinervum by steam distillation. We also evaluated the insect antifeedant effects ( Spodoptera littoralis , Leptinotarsa decemlineata, Myzus persicae and Rhopalosiphum padi ) and nematicidal activity ( Meloidogyne javanica ) of the oils, their major components and their synergistic interactions. Safrole was the major component (78–81%) followed by terpinolene (5–9%). The EOs tested were effective insect Antifeedants. Safrole, explained most of the insect antifeedant action of P. hispidinervum EOs. When safrole and terpinolene were tested in binary combinations, low ratios of safrole improved the antifeedant effects of terpinolene. P. hispidinervum EOs caused higher mortality of M. javanica juveniles than their major components. In binary combinations, low ratios of terpinolene increased the nematicidal effects of safrole. The EO treatment strongly suppressed nematode egg hatching and juvenile infectivity. P. hispidinervum EOs affected the germination of S. lycopersicum and L. sativa mostly at 24 h of treatment, being L. sativa the most sensitive. Safrole moderately affected germination and root growth of L. sativa , S. lycopersicum and L. perenne . Terpinolene only affected S. lycopersicum root growth.
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Antifeedant and Phytotoxic Activity of the Sesquiterpene p-Benzoquinone Perezone and Some of its Derivatives
Journal of Chemical Ecology, 2008Co-Authors: Eleuterio Burgueño-tapia, Azucena González-coloma, Lucia Castillo, Pedro Joseph-nathanAbstract:The sesquiterpene p -benzoquinone perezone ( 1 ), isolated from Perezia adnata var . alamani (Asteraceae), and its non-natural derivatives isoperezone ( 2 ), dihydroperezone ( 3 ), dihydroisoperezone ( 4 ), and anilidoperezone ( 5 ) were tested as Antifeedants against the herbivorous insects Spodoptera littoralis , Leptinotarsa decemlineata , and Myzus persicae . Compounds 1 – 5 exhibited strong antifeedant activity against L. decemlineata and M. persicae , and elicited a low response by S. littoralis . Antifeedant activity on L. decemlineata and M. persicae increased when the hydroxyl group at C-3 in perezone ( 1 ) was changed to C-6 to give isoperezone ( 2 ). The same effect was found with hydrogenation of the double bond of the alkyl chain of (1) to yield dihydroperezone ( 3 ). In contrast, hydrogenation of this double bond in isoperezone ( 2 ) to give dihydroisoperezone ( 4 ) led to a reduction in antifeedant activity. Determination of the phytotoxic activity of 1 – 5 revealed that 3 had a significant inhibition effect on Lactuca sativa radicle length growth.
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Structural diversity and defensive properties of diterpenoid alkaloids
Phytochemistry Reviews, 2007Co-Authors: Matías Reina, Azucena González-colomaAbstract:Diterpenoid alkaloids are compounds of pharmacological interest. Forty four C_19 norditerpenoid (NDAs) and 23 C_20 diterpenoid (DAs) alkaloids isolated from Aconitum , Delphinium and Consolida species were tested for their insecticidal effects (antifeedant and toxic) on Spodoptera littoralis and Leptinotarsa decemlineata , their cytotoxicity on tumoral cell lines with several multidrug resistance mechanisms, and their antiparasitic effects against Trypanososma cruzi and Leishmania infantum . Overall, C_19 norditerpene alkaloids (NDAs) resulted better insect Antifeedants and post-ingestive toxicants than the related C_20 diterpene alkaloids (DAs). Their antifeedant or insecticidal potencies did not parallel their reported nAChR binding activity, but did correlate␣with the␣agonist/antagonist insecticidal/ antifeedant model proposed for nicotininc insecticides.␣Among the most potent Antifeedants (EC_50
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Structural Diversity and Defensive Properties of Norditerpenoid Alkaloids
Journal of Chemical Ecology, 2004Co-Authors: Azucena González-coloma, Omar Santana, Matías Reina, Alberto Medinaveitia, Ana Guadaño, Rafael Martínez-díaz, Lastenia Ruiz-mesía, Allenger Alva, Maritza Grandez, Rafael DíazAbstract:We have tested the insect antifeedant and toxic activity of 43 norditerpenoid alkaloids on Spodoptera littoralis and Leptinotarsa decemlineata including eserine (physostigmine), anabasine, and atropine. Antifeedant effects of the test compounds were structure- and species-dependent. The most active Antifeedants to L. decemlineata were 1,14-diacetylcardiopetaline ( 9 ) and 18-hydroxy-14- O -methylgadesine ( 33 ), followed by 8- O -methylconsolarine ( 12 ), 14- O -acetyldelectinine ( 27 ), karakoline ( 7 ), cardiopetaline ( 8 ), 18- O -demethylpubescenine ( 13 ), 14- O -acetyldeltatsine ( 18 ), takaosamine ( 21 ), ajadine ( 24 ), and 8- O -methylcolumbianine ( 6 ) (EC_50 45). Orally injected S. littoralis larvae were negatively affected by 1 , cardiopetaline ( 8 ), 10 , 1,14- O -acetylcardiopetalidina ( 11 ), 12 , 14 , 1,18- O -diacetyl-19-oxo-gigactonine ( 41 ), olivimine ( 43 ), and eserine in varying degrees. Their antifeedant or insecticidal potencies did not parallel their reported nAChR binding activity, but did correlate with the agonist/antagonist insecticidal/antifeedant model proposed for nicotininc insecticides. A few compounds [ 14 , tuguaconitine ( 38 ), 14-demethyldelboxine ( 40 ), 19 , dehydrodelsoline ( 36 ), 18- O -demethylpubescenine ( 13 ), 41 , 9 , and delcosine ( 23 )] had selective cytotoxic effects to ward insect-derived Sf9 cells. None were cytotoxic to mammalian CHO cells and none increased Trypanosoma cruzi mortality. The selective cytotoxic effects of some structures indicate that they can act on biological targets other than neuroreceptors.
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Antifeedant C20 diterpene alkaloids.
Chemistry & biodiversity, 2004Co-Authors: Azucena González-coloma, Matías Reina, Ana Guadaño, Rafael Martínez-díaz, Allenger Alva, Jesús G. Díaz, Juan García‐rodriguez, Maritza GrandezAbstract:We have tested the insect antifeedant and toxic activity of 21 C 2 0 diterpenoid alkaloids on Spodoptera littoralis and Leptinotarsa decemlineata. The antifeedant effects of the test compounds were structure- and species-dependent. The most active Antifeedants to L. decemlineata and S. liitoralis were the rearranged form of hetisine (20: EC 5 0 = 1.7 μg/cm 2 ) and 19-oxodihydroatisine (9; EC 5 0 = 0.1 μg/cm 2 ), resp. Glandulosine (8) moderately affected orally injected S. littoralis larvae. A few compounds (13-oxocardiopetamine (4). 9, and atisinium chloride (13)) had cytotoxic effects to insect-derived Sf9 cells with varying degrees of selectivity with respect to mammalian CHO cells. Compounds 4 and 15,22-O-diacetyl,19-oxodihydroatisine (10) increased Trypattosoma cruzi mortality. Our results support the plant protective role of C 2 0 diterpenoid alkaloids and open a new field for parasite control strategies.
Göran Nordlander - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Phenylacetates with Benzoates and Phenylpropanoates as Antifeedants for the Pine Weevil, Hylobius abietis
Journal of agricultural and food chemistry, 2018Co-Authors: C. Rikard Unelius, Björn Bohman, Göran NordlanderAbstract:This study concludes an extensive investigation of Antifeedants for the pine weevil, Hylobius abietis (Coleoptera: Curculionidae), an economically important pest of planted conifer seedlings. Building on the previously reported antifeedant effects of benzoates and phenylpropanoids (aromatic compounds with one- or three-carbon-atom substituents on the benzene ring), we here report the antifeedant effects of compounds with two-carbon-atom side chains (i.e., phenylacetates). We also present new results; the best Antifeedants from the benzoate class were tested at 10-fold lower concentrations in order to find the optimal Antifeedants. Generally, for all three compound classes, efficient Antifeedants were found to have one or two methyl, chloro, or methoxy substituents on the aromatic ring. For monosubstituted phenylpropanoids, the substituent preferably should be in the para-position. In the search for synergistic antifeedant effects among the three compound classes, combinations of compounds from the three classes were tested in binary and ternary mixtures.
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Antifeedants produced by bacteria associated with the gut of the pine weevil hylobius abietis
Microbial Ecology, 2017Co-Authors: Karolin Axelsson, Göran Nordlander, Henrik Nordenhem, Vera Konstanzer, Gunaratna Kuttuva Rajarao, Olle Terenius, Lisa Seriot, Annakarin BorgkarlsonAbstract:The pine weevil, Hylobius abietis, is a severe forest pest insect as it feeds on newly planted conifer seedlings. To identify and develop an antifeedant could be one step towards the protection of seedlings from feeding damage by the pine weevil. With the aim to trace the origin of the Antifeedants previously found in feces of the pine weevil, we investigated the culturable bacteria associated with the gut and identified the volatiles they produced. Bacterial isolates were identified by 16S ribosomal RNA gene analysis. The volatile emissions of selected bacteria, cultivated on NB media or on the grated phloem of Scots pine twigs dispersed in water, were collected and analyzed by solid-phase microextraction gas chromatography-mass spectrometry. The bacterial isolates released a variety of compounds, among others 2-methoxyphenol, 2-phenylethanol, 3-methyl-1-butanol, 1-octen-3-ol, 3-octanone, dimethyl disulfide, and dimethyl trisulfide. A strong antifeedant effect was observed by 2-phenylethanol, which could thus be a good candidate for use to protect planted conifer seedlings against feeding damage caused by H. abietis.
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Quantitative Structure-Activity Relationships of Pine Weevil Antifeedants, a Multivariate Approach
Journal of agricultural and food chemistry, 2007Co-Authors: Kerstin Sunnerheim, Björn Bohman, Göran Nordlander, Henrik Nordenhem, Claes Hellqvist, Anna-karin Borg-karlson, Anneli Nordqvist, C. Rickard Unelius, Anders KarlénAbstract:Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abietis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active Antifeedants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeedant activity.
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Structure-activity relationships of benzoic acid derivatives as Antifeedants for the pine weevil, Hylobius abietis.
Journal of chemical ecology, 2006Co-Authors: C. Rikard Unelius, Göran Nordlander, Henrik Nordenhem, Claes Hellqvist, Sacha Legrand, Anna-karin Borg-karlsonAbstract:Aromatic organic compounds found in the feces of the pine weevil, Hylobius abietis (L.) (Coleoptera: Curculionidae), have been shown to deter feeding behavior in this species, which is a serious pest of planted conifer seedlings in Europe. We evaluated 55 benzoic acid derivatives and a few homologs as Antifeedants for H. abietis. Structure-activity relationships were identified by bioassaying related compounds obtained by rational syntheses of functional group analogs and structural isomers. We identified five main criteria of efficiency as Antifeedants among the benzoic acid derivatives. By predicting optimal structures for H. abietis Antifeedants, we attempted to find a commercial antifeedant to protect conifer seedlings against damage by H. abietis in regenerating forests. New, highly effective Antifeedants are methyl 2,4-dimethoxybenzoate, isopropyl 2,4-dimethoxybenzoate, methyl 2-hydroxy-3-methoxybenzoate, methyl (3,5-dimethoxyphenyl)acetate, and methyl (2,5-dimethoxyphenyl)acetate. Of these, methyl 2,4-dimethoxybenzoate and isopropyl 2,4-dimethoxybenzoate have the highest antifeedant indices of all substances tested and are the best candidates for practical applications in order to protect planted seedlings in the field.
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Antifeedants in the Feces of the Pine Weevil Hylobius abietis : Identification and Biological Activity
Journal of chemical ecology, 2006Co-Authors: Anna-karin Borg-karlson, Henrik Nordenhem, Göran Nordlander, Anoma Mudalige, C. Rikard UneliusAbstract:Egg-laying females of the pine weevil, Hylobius abietis (L.), regularly deposit feces adjacent to each egg. Egg cavities are gnawed in the bark of roots of recently dead conifer trees. After egg deposition, the cavity is sealed by feces and a plug of bark fragments. Root bark containing egg cavities with feces is avoided as food by pine weevils, which indicates the presence of natural Antifeedants. Here we present the first results of the isolation and chemical analyses of antifeedant compounds in the feces of H. abietis. In feeding bioassays, methanol extracts of the feces revealed strong antifeedant properties. Methanol extracts were fractionated by medium-pressure liquid chromatography and the antifeedant effects were mainly found in the fractions of highest polarity. Volatile compounds in the active fractions were identified by gas chromatography-mass spectrometry (GC-MS) and the nonvolatile compounds were characterized by pyrolysis-GC-MS. Based on mass spectra, a number of compounds with various chemical structures were selected to be tested for their antifeedant properties. Antifeedant effects were found among compounds apparently originating from lignin: e.g., a methylanisol, guaiacol, veratrol, dihydroxybenzenes, and dihydroconiferyl alcohol. A weak effect by fatty acid derivatives was found. The types of naturally occurring antifeedant compounds identified in this study may become useful for the protection of planted conifer seedlings against damage by H. abietis.
Jae Hak Kim - One of the best experts on this subject based on the ideXlab platform.
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Antifeedant Effects of Proteinase Inhibitors on Feeding Behaviors of Adult Western Corn Rootworm (Diabrotica virgifera virgifera)
Journal of Chemical Ecology, 2003Co-Authors: Jae Hak Kim, Christopher A MullinAbstract:Low-molecular-weight peptidyl proteinase inhibitors (PIs) including leupeptin, calpain inhibitor I, and calpeptin were found to be potent Antifeedants for adult western corn rootworm (WCR) against the phagostimulation of cucurbitacin B (Cuc B) or a corn pollen extract (CPE). Leupeptin was the strongest (ED_50 = 0.36 and 0.55 nmol/disk for Cuc B and CPE, respectively) among PIs tested with an antifeedant potency much stronger than the steroid progesterone (ED_50 = 2.29 and 5.05 nmol/disk for Cuc B and CPE, respectively), but slightly less than the reference alkaloid, strychnine (ED_50 = 0.17 and 0.37 nmol/disk for Cuc B and CPE, respectively). All active PIs contain a di- or tripeptidyl aldehyde moiety, indicating that PIs exert their antifeedant effects by covalent interaction with putative sulfhydryl (SH) groups on taste receptors as do these PIs with cysteine proteinases. However, opposite inhibition potency against Cuc B versus CPE by two thiol-group reducing agents, DTT and L-cysteine, and the results with other cysteine-modifying reagents obscure the net functional role of SH groups at WCR taste chemoreceptors. Surprisingly, the model phagostimulant for diabroticites, Cuc B, was more easily counteracted by these feeding deterrents than the stimulants present in CPE. Three-dimensional structure–antifeedant relationships for the PIs suggest that a novel taste chemoreception mechanism exists for these peptidyl aldehydes or that they fit partially into a strychnine binding pocket on protein chemoreceptors. Favorable economic benefit may be achieved if PIs are discovered to be useful in adult WCR control, since both pre- and postingestive sites would be targeted.
C. Rikard Unelius - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Phenylacetates with Benzoates and Phenylpropanoates as Antifeedants for the Pine Weevil, Hylobius abietis
Journal of agricultural and food chemistry, 2018Co-Authors: C. Rikard Unelius, Björn Bohman, Göran NordlanderAbstract:This study concludes an extensive investigation of Antifeedants for the pine weevil, Hylobius abietis (Coleoptera: Curculionidae), an economically important pest of planted conifer seedlings. Building on the previously reported antifeedant effects of benzoates and phenylpropanoids (aromatic compounds with one- or three-carbon-atom substituents on the benzene ring), we here report the antifeedant effects of compounds with two-carbon-atom side chains (i.e., phenylacetates). We also present new results; the best Antifeedants from the benzoate class were tested at 10-fold lower concentrations in order to find the optimal Antifeedants. Generally, for all three compound classes, efficient Antifeedants were found to have one or two methyl, chloro, or methoxy substituents on the aromatic ring. For monosubstituted phenylpropanoids, the substituent preferably should be in the para-position. In the search for synergistic antifeedant effects among the three compound classes, combinations of compounds from the three classes were tested in binary and ternary mixtures.
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Structure-activity relationships of benzoic acid derivatives as Antifeedants for the pine weevil, Hylobius abietis.
Journal of chemical ecology, 2006Co-Authors: C. Rikard Unelius, Göran Nordlander, Henrik Nordenhem, Claes Hellqvist, Sacha Legrand, Anna-karin Borg-karlsonAbstract:Aromatic organic compounds found in the feces of the pine weevil, Hylobius abietis (L.) (Coleoptera: Curculionidae), have been shown to deter feeding behavior in this species, which is a serious pest of planted conifer seedlings in Europe. We evaluated 55 benzoic acid derivatives and a few homologs as Antifeedants for H. abietis. Structure-activity relationships were identified by bioassaying related compounds obtained by rational syntheses of functional group analogs and structural isomers. We identified five main criteria of efficiency as Antifeedants among the benzoic acid derivatives. By predicting optimal structures for H. abietis Antifeedants, we attempted to find a commercial antifeedant to protect conifer seedlings against damage by H. abietis in regenerating forests. New, highly effective Antifeedants are methyl 2,4-dimethoxybenzoate, isopropyl 2,4-dimethoxybenzoate, methyl 2-hydroxy-3-methoxybenzoate, methyl (3,5-dimethoxyphenyl)acetate, and methyl (2,5-dimethoxyphenyl)acetate. Of these, methyl 2,4-dimethoxybenzoate and isopropyl 2,4-dimethoxybenzoate have the highest antifeedant indices of all substances tested and are the best candidates for practical applications in order to protect planted seedlings in the field.
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Antifeedants in the Feces of the Pine Weevil Hylobius abietis : Identification and Biological Activity
Journal of chemical ecology, 2006Co-Authors: Anna-karin Borg-karlson, Henrik Nordenhem, Göran Nordlander, Anoma Mudalige, C. Rikard UneliusAbstract:Egg-laying females of the pine weevil, Hylobius abietis (L.), regularly deposit feces adjacent to each egg. Egg cavities are gnawed in the bark of roots of recently dead conifer trees. After egg deposition, the cavity is sealed by feces and a plug of bark fragments. Root bark containing egg cavities with feces is avoided as food by pine weevils, which indicates the presence of natural Antifeedants. Here we present the first results of the isolation and chemical analyses of antifeedant compounds in the feces of H. abietis. In feeding bioassays, methanol extracts of the feces revealed strong antifeedant properties. Methanol extracts were fractionated by medium-pressure liquid chromatography and the antifeedant effects were mainly found in the fractions of highest polarity. Volatile compounds in the active fractions were identified by gas chromatography-mass spectrometry (GC-MS) and the nonvolatile compounds were characterized by pyrolysis-GC-MS. Based on mass spectra, a number of compounds with various chemical structures were selected to be tested for their antifeedant properties. Antifeedant effects were found among compounds apparently originating from lignin: e.g., a methylanisol, guaiacol, veratrol, dihydroxybenzenes, and dihydroconiferyl alcohol. A weak effect by fatty acid derivatives was found. The types of naturally occurring antifeedant compounds identified in this study may become useful for the protection of planted conifer seedlings against damage by H. abietis.