5α-Reductase inhibitory component from leaves ofArtocarpus altilis

The inhibitory effects of 17 samples prepared from Thailand plants on 5-reductase activity were examined. The acetone extract of leaves ofArtocarpus altilis showed potent 5-reductase inhibitory activity. Fractionation guided by 5-reductase inhibition led to the isolation of 2-geranyl-2,3,4,4-tetrahydroxydihydrochalcone from the acetone extract of leaves ofA. altilis. This compound showed more potent inhibitory effect (IC₅₀=38M) than-linolenic acid known as a naturally occurring potent inhibitor.     

Absolute configuration of arylglycerol-β-aryl ethers obtained by asymmetric reduction of the correspondingα-ketonic compound with intactFusarium solani cells

When (±)--oxo-guaiacylglycerol--(vanillic acid) ether (1) is degraded byFusarium solani M-13-1, the-ketone is initially reduced to giveerythro andthreo guaiacylglycerol--(vanillic acid) ethers (2), arylglycerol--aryl ethers, both of which are enantiomerically pure. The absolute configuration in each2 was determined by Mosher's method; the products were converted to,-di-(R)--methoxy--trifluoromethylphenylacetates (MTPA esters) (3) oferythro (-)- andthreo (+)-veratrylglycerol--(methyl vanillate) ethers (3), whose¹H nuclear magnetic resonance (NMR) spectra were examined and compared with those of four di-(R)-MTPA ester (3) diastereomers from chemically synthesizederythro (±)-3 andthreo (±)-3. To assign the- and-MTPA-OCH₃ peaks, the¹H NMR scans of several compounds that have substructures of 3 and their 3,4,5-trimethoxyphenyl analogues were examined. When a racemic alcohol reacts with (R)-MTPA to give a pair of (R)-MTPA ester diastereomers, the value was defined as the absolute value of the difference in the¹H chemical shifts of the peak between the diastereomers. It was found that the values of-MTPA-OCH₃ were larger than those of-MTPA-OCH₃ owing to a shielding effect of the veratryl ring located on the-MTPA-OCH₃, and that the-MTPA-OCH₃ peaks in the 3,4,5-trimethoxyphenyl compounds shifted downfield relative to those in the veratryl compounds. On the basis of the¹h NMR data of (R)-MTPA esters, the absolute configuration of the four chemically prepared diastereomers (3) were determined. The catabolicerythro 3 [fromerythro (-)-3] andthreo 3 [fromthreo (+)-3] were identical to (R, S, R)-erythro 3 and (R, S, S)- threo 3, respectively. An hydrogen species in the fungal reduction would attack the-ketone fromre-face of both (R)-1 and (S)-1, givingerythro (S, R)-2 andthreo (S, S)-2, respectively.Part of this paper was presented at the 33rd Lignin Symposium, Tsukuba, November 1988     

Synthesis of isoacteoside, a dihydroxyphenylethyl glycoside

The total chemical synthesis of isoacteoside (1), 2-(3,4-dihydroxyphenyl)ethyl 6-O-caffeoyl-3-O-(-l-rhamnopyranosyl)--d-glucopyranoside, is described. An acteoside acetate with benzyl groups at the catechols (3: 2-(3,4-dibenzyloxyphenyl)ethyl 2,6-di-O-acetyl-4-O-[3,4-bis(O-benzyl)caffeoyl]-3-O-(-l-rhamnopyranosyl)--d-glucopyranoside) was treated with a solution of methy-lamine in methanol (MeNH₂ in MeOH) to perform both deacetylation and caffeoyl migration, affording an isoacteoside derivative with benzyl groups at the catechols4b: 2-(3,4-dibenzyloxyphenyl)ethyl 6-O-[3,4-bis(O-benzyl) caffeoyl] -3-O-(-l-rhamnopyranosyl)--d-glucopyranoside —in 34% yield. Debenzylation of4b was successfully accomplished by catalytic transfer hydrogenation using 1,4-cyclohexadiene to give the target compound isoacteoside (1) in 54% yield.¹H and¹³C nuclear magnetic resonance spectral data of the synthesized isoacteoside (1) were identical with those of the natural isoacteoside isolated fromPaulownia tomentosa (Thumb.) Steud.Part of this research was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001     

Two lignan rhamnosides from birch leaves

The extractives of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves were investigated. Two lignan glycosides were isolated, and their structures were elucidated to be 1-(4-hydroxy-3-methoxyphenyl)-2-[1-(3--l-rhamnopyranosyloxypropyl)-3-hydroxyphenoxy]-1,3-propanediol (I) and a new 2,3-dihydro-2-arylbenzofuran configuration neolignan,cis-2,3-dihydro-2-(4--l-rhamnopyranosyloxy-3-methoxyphenyl)-3-hydroxymethyl-7-hydroxy-5-benzofuranpropanol (II). These neolignan rhamnosides were newly found in shirakamba.     

A new diterpene dimer from the bark ofChamaecyparis obtusa

This paper describes characterization of diterpenes of the bark of Japanese cypress,Chamaecyparis obtusa (S. and Z.) Endl, without the resinous stem canker to learn the difference between the cypress bark affected with the canker. A diterpene dimer and two diterpenes, 6,12-dihydroxyabieta-8,11,13-trien-7-one and 6,12-dihydroxyabieta-5,8,11, 13-tetraen-7-one, were firstly isolated from Japanese cypress. The dimer, 6-(abieta-6,8,11, 13-tetraenyl-12-oxy)-7-methoxyabieta-8,11,13-trien-12-ol, was a new compound. It is a terpene indicative ofC. obtusa not infected with the resinous stem canker. Five known diterpenes were also isolated.     

The reaction of guaiacol with iron III and chromium VI compounds as a model for wood surface modification

Summary The reaction of ferric chloride with the lignin model guaiacol affords primarily a complex mixture of coupled guaiacol oligomers. Major components were the symmetrical carbon-carbon coupled dimer 3,3-dimethoxy-[1,1-biphenyl]-4,4diol and the trimer 3,3,5-trimethoxy-[1,1:3,1-terphenyl]-4,4,4-triol which were isolated by preparative HPLC and characterized by ¹HNMR spectroscopy and mass spectrometry. An unstable component believed to be a 4,4-diphenoquinone derived from the trimer was also prominent. The reaction of chromium trioxide with guaiacol yields the same dimer, trimer and diphenoquinone as well as 2-methoxy-p-benzoquinone. The major product with chromium trioxide, however, is an inert, highly insoluble polymer which was shown by degradation to contain guaiacol oligomers bound or crosslinked by hydroxylated chromium species. Magnetic susceptibility measurements clearly indicated that the valency of chromium in the polymer was + 3. It is postulated that similar complexes formed from phenolic lignin units are responsible for the weather resistance of chromium trioxide treated wood surfaces. In a broader context this study is relevant to the fixation of hexavalent chromium from a range of widely used wood preservative formulations.The authors wish to thank the following: Tom Syers (CSIRO Division of Forest Products) for technical assistance, Mary Reilly (CSIRO Division of Forest Products) for NMR spectral determinations and Ivan Vit (CSIRO Division of Chemicals and Polymers) for mass spectral determinations     

Inhibition ofTrichoderma cellulase activity by a stilbene glucoside fromPicea glehnii bark

The stilbene glucoside isorhapontin (5,4-dihydroxy-3-methoxystilbene-3--D-glucoside) is the major constituent of the ethyl acetate extracts fromPicea glehnii bark. Isorhapontin inhibited the hydrolytic activity ofTrichoderma cellobiohydrolase I (CBH I) for both bacterial microcrystalline cellulose and the soluble cellooligosaccharide celloheptaitol. The inhibitory effect for celloheptaitol, however, was more drastic than that for bacterial microcrystalline cellulose. The hydrolytic activity of the CBH I core domain for celloheptaitol was also inhibited by isorhapontin to a similar extent, suggesting that the interaction between isorhapontin and the core domain of CBH I is the reason for this phenomenon. The inhibition of CBH I activity by isorhapontin showed mixed noncompetitive and uncompetitive types in a concentration of the inhibitor of less than 125M. TheK _i andK _i values were estimated to be 57.2 and 33.3M, respectively. Whereas isorhapontin strongly inhibited CBH I activity, its aglycone isorhapontigenin (3-methoxy-3,5,4-trihydroxystilbene) showed almost no inhibition. Consequently, both the stilbenic and the-glucosidic structures in isorhapontin are essential for the inhibitory effect on CBH I activity. Isorhapontin also inhibited the activity ofTrichoderma endoglucanase I for celloheptaitol, whereas almost no effect was observed for the activities of both endoglucanases II and III.An outline of this work was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999     

Genetic variation in minerals,crude protein and structural carbohydrates of foliage in provenances of young plants ofProsopis cineraria (L.) Druce in India

Prosopis cineraria is an important species for aridzone agroforestry in India. Information on the chemical composition and nutritive value of the leaves of young trees that will be useful in screening the provenances, is lacking. Chemical composition (N, P, K, Ca, Mg, Na), crude protein, and structural carbohydrates (neutral detergent fibre, acid detergent fibre, cellulose, hemicellulose, and lignin) of the foliage of one-year-old plants of 31 provenances ofProsopis cineraria were determined. The seeds were collected from 16°50 N to 29°55 N latitude and 69°49 E to 78°03 E longitude in India, and grown at Hisar (29°10 N latitude, 75°46 E longitude and 215 m altitude). Mineral contents (except N and P), crude protein, and structural carbohydrates varied significantly (p<0.05) between provenances, and the greatest amount of N, P, crude protein, NDF, ADF and lignin contents were found in Hisar provenance. The in vitro dry matter digestibility varied from 18.2% in Gandhinagar provenance to 34.0% in that of Barmer provenance.     

Semi-quantitative method to evaluate the α-carbonyl content in lignin

A method to estimate the content of -carbonyl structures in lignin was developed. This method consists of two successive treatments: NaBD₄ treatment of pulp to reduce an -carbonyl structure in lignin, and nitrobenzene oxidation. NaBD₄ was used to convert an -carbonyl structure to a deuterium-labeled hydroxymethine structure. The ratio of D-vanillin [(HO)(H₃CO)C₆H₃CDO] to H-vanillin [(HO)(H₃CO)C₆H₃CHO] or that of their syringyl analogues obtained by nitrobenzene oxidation was used as the measure of the content of -carbonyl structure. Model experiments demonstrated that when sodium hydroxide was used as alkali for the nitrobenzene oxidation, the retention of deuterium at the side chain -position was very low due to the displacement of deuterium with hydrogen by an unknown reaction mechanism. In order to depress this unexpected displacement, the reaction conditions of the nitrobenzene oxidation were modified. The modified nitrobenzene oxidation employs 0.5mol/l of lithium hydroxide as a reaction medium instead of 2.0mol/l sodium hydroxide. By this modification, this method could successfully trace the formation and the degradation of the -carbonyl structure in milled wood lignins.This paper was presented in part at the 11th International Symposium on Wood and Pulping Chemistry, Nice, France, June 2001 and at the 46th Lignin Symposium, Kyoto, Japan, November 2001     

Lignans ofLinum flavum var.compactum

A new dibenzylbutyrolactone lignan 7.6-dihydroxybursehernin, together with six known lignans (pinoresinol, lariciresinol, secoisolariciresinol,-peltatin,-peltatin, 5-methoxypodophyllotoxin) were isolated from the methanol extracts ofLinum flavum var.compactum. The enantiomeric analysis of pinoresinol and lariciresinol isolated from the species, which are upstream lignans in the lignan biosynthetic pathway, indicated that they are not optically pure, which is in accordance with our recent findings on lignans occurring in other plant species.Parts of this report were presented at the 42nd Lignin Symposium, Sapporo, October 1997; and the 43rd Lignin Symposium, Fuchu, October 1998     

Effects of stilbenes from bark of <Emphasis Type="Italic">Picea glehnii</Emphasis> (Sieb. et Zucc) and their related compounds against feeding behaviour of <Emphasis Type="Italic">Reticulitermes speratus</Emphasis> (Kolbe)

The effects of stilbene glucosides and related compounds on termite feeding behavior were investigated using paper disc methods against the subterranean termite Reticulitermes speratus. The stilbene-rich fraction and isorhapontin (3-methoxy-3,4, 5-trihydroxystilbene-3--d-glucoside) from bark extracts of Picea glehnii showed avoidance by termites in choice tests. In the no-choice tests using compounds purified from the stilbene-rich fraction, the largest feeding deterrent effect was observed for piceid (3,4,5-trihydroxystilbene-3--d-glucoside), followed by isorhapontin, and astringin (3,3,4,5-tetrahydroxystilbene-3--d-glucoside), at the concentrations from 0.63 to 2.5µmol/disc. No change in activity was observed at retentions of more than 5.0µmol/disc. When the activities of isorhapontin and its aglycone derivative (isorhapontigenin: 3-methoxy-3,4,5-trihydroxystilbene) were compared with that of taxifolin (3,3,4,5,7-pentahydroxyflavanone) in the no-choice test, the stilbenes exhibited a larger antifeedant potential. Methylation of isorhapontigenin increased its termiticidal activity.Part of this study was presented at the 32nd Annual Meeting of the International Research Group on Wood Preservation, 2001     

Dynamic properties of three types of wood-based composites

This study used a vibration test method to show that grain angles of face veneer have substantial effects on sound velocities and dynamic Youngs moduli of three types of wood-based composites. The sound velocity at 0° grain angle of face veneer was the highest, and it decreased with increasing grain angle in the range of 0° to 90°. This tendency was similar to that for dynamic Youngs modulus. The relationship between the grain angle of face veneer and the sound velocity of three types of wood-based composites can be expressed in the form of Hankinsons equation or a second-order parabolic equation. This study also showed that the application of orthotropic elasticity theory was valid for the three types of wood-based composites. The relationship between the grain angle of the face veneer and the Youngs modulus of three types of wood-based composites can be expressed in the form of the Jenkin equation, Hankinsons equation, or a second-order parabolic equation. Rule of mixture can also be used to predict the Youngs modulus of wood-based composite from the Youngs moduli of the two elements.Part of this study was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, Japan, March 2003 and the 15th Annual Meeting of Chugoku Shikoku Branch of the Japan Wood Research Society, Higashi-Hiroshima, Japan, September 2003     

Preparation of liquid polyesterpolyols from glucose and its methyl derivative

Preparation of liquid polyols from d-(+)-glucose (Glc) and its derivative, methyl--d-glucoside (m-Glc), has been studied. Direct reaction of -caprolactone (CL) with Glc (CL:Glc = 2:1–5:1 in weight ratio) at 150°C using tin(II) 2-ethyl hexanoate (SnEht₂) (series A), in which melted Glc was suspended in CL, resulted in a dark-brown coloration of the reactants. The reaction was accompanied by formation of high molecular weight resins, a pH drop, production of water, and a considerable decrease in the hydroxyl value from the theoretically expected one. In the case of Glc/ethylene glycol (EG)/CL reaction system with SnEht₂ catalyst at 150°C (series B), in which the weight ratio of Glc to EG was fixed at 1:1, Glc dissolved in the EG/CL mixture, but the brown coloration of the reactant mixture still occurred. In this case, the formation of water was enhanced, but the other effects found in series A were suppressed to a considerable extent. In the m-Glc/CL/SnEht₂ reaction system (series C), in which m-Glc reacted with two to five times weight amounts of CL under the same conditions adopted in series A, development of the color, the production of high molecular weight materials and water, and the changes in pH and hydroxyl value were not observed. These results are discussed based on the chemical structural differences: Glc exists mostly in the hemiacetal form, but tautomerizes to the aldehyde, whereas m-Glc is an acetal and is protected from reversion to the aldehyde.     

Studies on the synthesis and properties of terpene-phenol-aldehyde resin with a high softening point

Synthesis conditions of terpene-phenol-aldehyde resin with a high softening point were studied based on the reactions among-pinene, phenol, and formaldehyde. A suitable catalyst system and the best processing conditions were obtained by laboratory experiments. The influence of the raw materials ratios, reaction temperature, reaction time, and catalyst dose on the softening point, yield, and color of the synthesized resin was examined. The physical and chemical characteristics of the resin were determined: softening point 140°C (ball and ring method); color value 7 (Gardner); acid value (KOH mg/g) <1; bromine value (Br₂ mg/100g) <64; saponification value (KOH mg/g) <1; average molecular weight 830. The yield of resin was more than 85% (based on the total raw material).     

Gas chromatographic and mass spectrometric (GC-MS) analysis of lignin-derived products from <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> treated in supercritical water

Sugi (Cryptomeria japonica D. Don) wood was treated with supercritical water (374°C, 22.1MPa), and fractionated into the water-soluble portion, the methanol-soluble portion, and the methanol-insoluble residue. The methanol-soluble portion mainly consisted of the lignin-derived products. To characterize the compounds in the methanol-soluble portion, gel permeation chromatographic (GPC) and gas chromatographic-mass spectrometric (GC-MS) analyses were performed. The GPC analysis indicated that the methanol-soluble portion contained lignin-derived monomeric and dimeric products. GC-MS analysis detected 31 products which were expected to be monomeric compounds, and 18 of these were identified to be guaiacol, methylguaiacol, ethylguaiacol, vinylguaiacol, eugenol, propylguaiacol, vanillin, cis-isoeugenol, homovanillin, trans-isoeugenol, acetoguaiacone, propioguaiacone, guaiacylacetone, 2-methoxy-4-(1-hydroxypropyl)phenol, homovanillic acid, 2-methoxy-4-(prop-1-en-3-one)phenol, coniferyl aldehyde, and ferulic acid. In addition, 22 dimeric products were detected, and 4 of these were believed to be compounds with biphenyl type (5-5), diphenylethane type (-1), stilbene type (-1), and phenylcoumaran type (-5) structures. These results clearly indicated that the methanol-soluble portion included various monomeric and dimeric compounds produced as a result of the cleavage of ether linkages and propyl chains of lignin.     

Zur Wirkung von Sevin auf Regenwürmer

Zusammenfassung In Freiland- und Laborversuchen wurde die Wirkung des Pflanzenschutzmittels Sevin auf Regenwürmer untersucht. Dieser Stoff ist in Pulverform und als Suspension für diese Organismen außerordentlich gefährlich. Schon der Kontakt mit sehr geringen Mengen bewirkt schwere Lähmungserscheinungen und irreversible histopathologische Schäden.

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Summary Experiments in the field as well as in the laboratory showed up the effect of the pesticide Sevin on rainworms. In the form of powder as well as a suspension this material is extremely toxic for them. Contact with smallest quantities even causes severe paralysis and irreversible histopathologic damages.

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Résumé Aussi bien dans la nature que au laboratoire nous avons étudié l'activité de l'insecticide Sevin sur les vers de terre. Ce produit est en poudre ou en suspension extrémement dangereux pour ces organismes. Le seul contact avec des quantités minimes de ce produit provoquent des phénomènes de paralysie et des troubles histopathologiques irreversibles.

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SEVIN . . .

     

Vertikalbewegungen Rickettsiose-kranker Larven vonAmphimallon solstitiale (LINNAEUS),Anomala dubia aenea (DE GEER) undMaladera brunnea (LINNAEUS)(Col., Lamellicornia)

Zusammenfassung DurchRickettsiella melolonthae (Krieg) PHILIP infizierte Maikäfer-Engerlinge wandern während des Spätherbstes und Winters im Freiland absterbend auf die Erdoberfläche. Als Begleitarten inMelolontha Larvenpopulationen kamen im Gebiet vor:Amphimallon solstitiale (L.),Anomala dubia aenea (DeG.) undMaladera brunnea (L.). MitR. melolonthae künstlich infiziert, zeigten sie im Orientierungsversuch die gleiche Aufwanderungstendenz wie kranke Maikäferengerlinge, am deutlichsten die vonM. brunnea. Auf dem Waldboden fanden sich kranke Larven dieser Art in einigen Fällen.

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Summary Larvae ofMelolontha spp. infested withRickettsiella melolonthae (Krieg) PHILIP move during October– January to the top of the soil where they eventually die. Larvae ofAmphimallon solstitiale (L.),Anomala dubia aenea (DeG.) andMaladera brunnea (L.) are susceptible forR. melolonthae, too. In experiments, artificially infested individuals showed a similar tendency to move upward. This was most pronounced inM. brunnea, of which some infested larvae were found on the forest floor.

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Résumé Larves du hanneton, infectées parRickettsiella melolonthae (Krieg) PHILIP, se rendent à la surface de la terre au fin de l'automme et dans l'hivers. Comme espèces accompagnant les populations larvaires deMelolontha nous avons trouvés:Amphimallon solstitiale (L.),Anomala dubia aenea (DeG.) etMaladera brunnea (L.). Ils out démonstré, après une infection artificielle avecR. melolonthae, la mème tendence dans les essais d'orientation comme les vers blancs malades deMelolontha. Le phé nomène etait le plus prononcé parmi les larves deMaladera. De cette espèce nous avons trouvés plusieurs larves malades à la surface de la terre en plein champs.

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Rickettsiella melolonthae (Krieg) Philip Melolontha- . . Melolontha- :Amphimallon solstitiale (L.),Anomala dubia aenea (De G.) Maladera brunnea (L.). R. melolonthae , Melolontha-, M. brunnea. .

     

Generationszahl der RübenfliegePegomyia hyoscyami betae Curt.

Summary During the years 1959–1961 the number of generations was followed in Spinach Leaf Miner (Pegomyia hyoscyami betae Curt.) in central Bohemia at 310 m above sea level and in the year 1961 in southern Bohemia at 450 m. The larvae and the eggs were studied on the leaves at regular 10–14 days' intervals by controlling each plant and images by means of a sweeping method. There have been acertained two generations in the year 1959 and three generations in the year 1961 in central Bohemia and two generations in the year 1961 in southern Bohemia. The occurence of every generation of larvae on the suggar-beet was separate and the previous and the consecutive generation did not overlop.The origin of the erroneous date on 6–7 generations of this species (Rambousek, Neuwirth, 1931) has been also cleared up in this article. This statement has been taken over by Sorauer (1953) from the Review of Applied Entomology (1931) and has been lately mentioned by many authors. F. Neuwirth gave a personal information, that the statement on 6–7 generations occurence of Spinach Leaf Miner has been found on the basis of theoretical calculation (from the lenght of one generation in spring and not on the basis of the facts found in natural conditions).

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Résumé En 1959–1961 le nombre des générations de la mouche de la betterave a été observé dans la Bohème Centrale á l'altitude de 310 m audessus de la mer et en 1961 dans le Sud de la Bohème á l'altitude de 450 m. Les larves et les oeufs ont été observé sur les feuilles dans les intervalles de 10–14 jours regulierement effectués sur chaque plante et imagines en particulier par le filet fauchior. En 1959 deux générations et en 1960 et 1961 trios géné rations dans la Bohéme Centrale, ainsi que en 1961 deux générations dans le Sud de la Boheme ont été constates. La prence de chaque génération des larves sur la betterave aété separée et les générations consecutives ne malaient pas presque jamais avec les précedents.Dans cet travail l'auteur a clarifié comment une donnée fautive sur 6–7 générations de cette espéce est survenu (Rambousek et Neuwirth, 1931). Cette donnée orginante de Review of Applied Entomology [1931] a été reprise par Sorauer (1953) et elle a été ensuite récemment mentionée par d'autres auteurs. Selon une déclaration personelle de Mr. F. Neuwirth les donées des 6–7 générations de la mouche de la betterave en Tschécoslovaquie ent été acquis par une évaluation théoretique (se basant sur la durée de la génération du printemps et non sur les resultats des observations réelles dans les conditions naturelles.

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1959–61 . (310 . ) 1961 . (450 . ). 10–14 , . 1959 . 2 , 1960 . — 3, 1961 . — 2 . , . , 6–7 (Rambousek, Neuwirth 1931). . . 6–7 , , .

     

Richtungen der angewandten Entomologie in Bulgarien

Summary For protection of agricultural crops, archards, forests and stored products a system of institutes for vegetative protection have been gradually built in Bulgaria within the last fifteen years. Now a leading part in the study of pests and diseases of plants are taking the Academy of Rural Economy Sciences and the Institutes for Plant Protection, for Forest Protection, the Zoological Institute by the Bulgarian Academy of Science, the Higher Rural Economy Institute and the Higher Forest Institute. Specialists of all ranks are working at these institutes: academicians, member correspondents, professors, senior and junior scientific collaborators and a great number of experts and assistants. Parallel with the studies of specific composition of pestilent insects, their biology is being explored and experiments are being made with insecticides. An inquiry is also being undertaken for utilization biologic combat against noxious insects. In aid of scientific institutes a dense network of services for heading the research work and combat on the terrain has been organized.

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Résumé Pour la défense des cultures agricoles, des vergers, des forêts et des produits récoltés, un système d'instituts pour la défense végétale a été successivement dé veloppé en Bulgarie pendant les dernières quinze années. Actuellement l'Academie des sciences de l'economie rurale et les Instituts pour la défense végétale ont le rôle dirigeant dans les recherches de la nocivité et des maladies sur les plantes. Dans ces instituts travaillent des spécialistes de toutes les catégories scientifiques: des académiciens, des membres-correspondants, des professeurs, des travailleurs scientifiques supérieurs et plus jeunes, avec un grand nombre d'aides-spécialistes. Parallèllement à l'étude de composition specifique des insectes nuisibles on étudie sa biologie, de même on fait des expériences avec des insecticides. Aussi on cherche à utiliser la lutte biologique contre les insectes nuisibles. Pour faciliter les instituts scientifiques dans cette lutte et leur recherche sur le terrain, un immense service est organisé dans tous les plus grands emplacements peuplés du pays.

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. , 15 , , , . . - , , , . - , , - . : , , , . , . . , . - , . .

     

Holzangriff durch Larven der AmpferblattwespeAmetastegia glabrata Fall.(Hym., Tenthredinidae)

Zusammenfassung Die Altlarven 2. Generation der AmpferblattwespeAmetastegia glabrata Fall. sind im Obstbau als Schädling bekannt. Die Schäden entstehen bei dem Versuch der Larven, in Früchten Puppenkammern anzulegen.Üblicherweise verpuppen sich die Larven in den trockenen Stengeln der Nährpflanzen(Polygonaceae) oder anderem trockenem oder verholzten Pflanzenmaterial.Es wird über einen gesicherten Fall berichtet, in demAmetastegia glabrata-Larven in verarbeitetem Nutzholz (Plakattafel) schädlich geworden sind. Ein weiterer Fall konnte nicht völlig geklärt werden; jedoch waren auch hier Blaltwespen-Larven in einer Wohnung in verarbeitetes Nutzholz (Türrahmen) eingedrungen.Nach dem geringen Umfang der Schäden, die nur durch die Anlage kurzer Puppenkammern in weichen Holzteilen entstehen, istAmetastegia glabrata in die Gruppe der gelegentlichen Holzzerstörer einzureihen. Allerdings kann durch diese Art völlig gesundes Holz im Freiland angegriffen werden.Holzschutzsalze vom U-Typ genügen zur Vorbeugung nicht. Vorbeugungs- und Bekämpfungsmaßnahmen werden besprochen.

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Summary Attack on wood by larvae of the dock sawfly Ametastegia glabiata Fall. (Hym., Tenthiedinidae) Normally the mature larvae of the last brood of the dock sawfly bore themselves for pupation into dry stems of plants.By the gnawing efforts in certain years of appearance in masses, however, they may attack fruit too, especially apples, and cause considerable damage by numerous gnawing spots.Besides these known injuries on fruitA. glabrata has now been stated in two cases as an occasionally dangerous animal to dry timber too.The damage caused is described by word and picture; preventive and curative measures are discussed.

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Résumé Attaque du bois par des larves de la Tenthrenidé Ametastegia glabrata Fall. (Hym., Tenthredinidae) Normalment les larves adultes de l'A. glabrata se forent dans les tiges sèches des plantes pour la mé tamorphose.Cependant aussi des fruits, surtout des pommes, sont attaqués par le ronger pendant les anées quand ces insectes paraîssent en masse. Des dommages considérables sont provoqués aux points d'attaque nombreux.A côté de ces dommages connus aux fruits l'A. glabrata a été constaté en deux cas comme causeur de dommage par occasion en bois sec de construction.Les dommages sont décrits et figurés; des methodes preventives et curatives sont discutées.

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? Ametastegia glabrata Fall. (Hym., Tenthredinidae) . , , , . Ametastegia glabrata Fall. ( ) . , .

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Mitteilung aus dem Holzschutzlaboratorium der Farbenfabriken Bayer AG., Werb Uerdingen