Browsing by Author "6805cc70-f0a6-4e1f-9f8a-c6a4b6ee7b8d"
Now showing items 41-60 of 90
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Escobar, Carlos A.; Sicker, Dieter; Niemeyer, Hermann M. (Kluwer Academic/Plenum Publishers, 1999)A total of 25 compounds including benzoxazinones, benzoxazolinones, and N-glyoxylamide derivatives were tested as antifeedants and antibiotics towards the aphid Sitobion avenae in diet bioassays. The antifeedant and mortality ...
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Lemaitre Bailey, Carmen; Pinto, Carlos; Niemeyer Marich, August (Kluwer Academic Publishers, 2014)Flowers that are pollinated both during the day and at night could exhibit two different groups of pollinators and produce two different sets of attractants and rewards. We explored the patterns of emission of flower scents ...
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Gonzáles, Wilfredo L.; Fuentes-Contreras, Eduardo; Niemeyer, Hermann M. (2002)Competition between phytophagous insects could be mediated by differential impact of natural enemies or by induced changes in host plant quality. The interaction between the aphids Sipha flava and Rhopalosiphum maidis on ...
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Lemaitre, Andrea B.; Troncoso, Alejandra J.; Niemeyer, Hermann M. (2012)The mistletoe Tristerix verticillatus (Loranthaceae) parasitizes within a small area of the Yerba Loca Nature Sanctuary near Santiago, Chile, three co-occurring hosts: Schinus montanus (Anacardiaceae), Fabiana imbricata ...
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Quiroz, Andrés; Fuentes-Contreras, Eduardo; Ramírez, Claudio C.; Russell, Graeme B.; Niemeyer, Hermann M. (Kluwer Academic/Plenum Publishers, 1999)Extractable metabolites from leaves (EM) and volatiles released from six Nothofagus species were analyzed by TLC and GC-MS, respectively. Aphids of the genus Neuquenaphis, closely associated to Nothofagus, were sampled on ...
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Zúñiga, Gustavo E.; Argandoña, Víctor H.; Niemeyer, Hermann M.; Corcuera, Luis J. (1983)The content of two hydroxamic acids, 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), in cultivated and wild species of Gramineae was determined. Zea mays and Triticum ...
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Niemeyer, Hermann M. (Kluwer Academic Publishers, 1988)Fifty-five accessions of Triticum species were analyzed for content of hydroxamic acids (Hx), a natural resistance factor against various organisms. Hx were found in all accessions analyzed. Extreme values were found in ...
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Niemeyer Marich, August (1988)Hydroxamic acids of the type 4-hydroxy-1,4-benzoxazm-3-ones constitute one of the most extensively studied secondary metabolites m relation to host plant resistance to pests and diseases They play a maJor role in the defence ...
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Niemeyer, Hermann M. (2009)Many cereals accumulate hydroxamic acids derived from 2-hydroxy-2H-1,4- benzoxazin-3(4H)-one. These benzoxazinoid hydroxamic acids are involved in defense of maize against various lepidopteran pests, most notably the ...
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Fuentes-Contreras, Eduardo; Pell, Judith K.; Niemeyer, Hermann M. (1998)Host-plant resistance can affect herbivorous insects and their natural enemies such as parasitoids and entomopathogenic fungi. This tritrophic effect acts on interspecific interactions between the two groups of natural ...
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Niemeyer Marich, August; Pesel, Erika; Franke, Stephan; Francke, Wittko (1989)DIMBOA (2,4-dihydroxy-7-methoxy- 1,4-benzoxazin-3-one was found in nymphs of the aphids Metopolophium dirhodum and Sitobion avenae which had fed on DIMBOA-containing wheat seedlings and artificial diets. DIMBOA levels found ...
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Thoison, Odile; Sévenet, Thierry; Niemeyer, Hermann M.; Russell, Graeme B. (2004)A bioassay-guided purification of the extracts of Nothofagus dombeyi and N. pumilio leaves yielded several triterpenes and flavonoids including 2-O-acetylmaslinic acid, 3-O-acetyl 20,24,25-trihydroxydammarane, and ...
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Bravo, Héctor R.; Niemeyer, Hermann M. (1986)Solubilities and IR spectra of DIMBOA in alcoholic solvents showed that the carbonyl group of DIMBOA is hydrogen-bonded to the solvent. Activation parameters of DIMBOA in the same solvents suggested that the decomposition ...
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Trigosso-Venario, Rodrigo; Labra, Antonieta; Niemeyer, Hermann M. (2002)For territorial organisms, recognition of familiar individuals can reduce the frequency and intensity of aggressive encounters ('dear enemy' phenomenon), stabilize social systems, and reduce the cost of territory maintenance. ...
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Catalán, Tamara P.; Niemeyer, Hermann M.; Kalergis, Alexis M.; Bozinovic, Francisco (2012)Since the preferential body temperature should positively correlate with physiological performance, behavioural fever should enhance an organism's immune response under an immune challenge. Here we have studied the ...
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Johansson, Christina; Pettersson, Jan; Niemeyer, Hermann M. (Czech Academy of Sciences, 1997)In olfactometric experiments a wingless adult of Sitobion avenae was attracted by odours of a wingless adult of Rhopalosiphum padi feeding on a wheat plant. When the stimulus consisted of either a wingless R. padi without ...
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Labra, Antonieta; Niemeyer, Hermann M. (Kluwer Academic/Plenum Publishers, 1999)Experimental tests were conducted to determine whether females and males of the tree-dwelling lizard Liolaemus tenuis (Tropiduridae) show intraspecific chemical recognition during breeding and postreproductive seasons. ...
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Isolation, characterization, and biological activity of naphthoquinones from Calceolaria andina L. Khambay, Bhupinder P.S.; Batty, Duncan; Cahill, Matthew; Denholm, Ian; Mead-Briggs, Mike; Vinall, Stephen; Niemeyer, Hermann M.; Simmonds, Monique S.J. (1999)Two compounds recognized as responsible for the insecticidal activity of extracts of Calceolaria andina L. (Scrophulariaceae) have been isolated and characterized as 2-(1,1-dimethylprop-2-enyl)3-hydroxy-1,4-naphthoquinone ...
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Torrico-Bazoberry, Daniel; Caceres-Sanchez, Liliana; Flores-Prado, Luis; Aguilera-Olivares, Daniel; FontÚrbel, Francisco E.; Niemeyer, Hermann M.; Pinto, Carlos F. (Blackwell Publishing Ltd, 2018)© 2018 The Royal Entomological Society 1. Insects exhibiting parental care usually can discriminate between kin and non-kin individuals, allowing parents to avoid investment in foreign offspring. 2. This study investigated ...
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Flores Prado, Luis; Niemeyer, Hermann M. (2010)The recognition of conspecifics is a central issue to social behaviour. In eusocial hymenopterans, kin recognition has been clearly demonstrated. Manuelia postica is a largely solitary bee species in which larvae develop ...