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271 results on '"Svatos Ales"'

1. Initial studies of mating disruption of the tomato moth, Tuta absoluta (Lepidoptera: Gelechiidae) using synthetic sex pheromone

Author

Michereff Filho Miguel, Vilela Evaldo F., Jham Gulab N., Attygalle Athula, Svatos Ales, and Meinwald Jerrold

Subjects
sex pheromone, mating disruption, Tuta absoluta, Scrobipalpuloides absoluta, Gelechiidae, tomato, Chemistry, QD1-999
Abstract

The potential of the synthetic major component of T. absoluta (Meyrick) sex pheromone for mating disruption was studied in small plots (0.01 hectares) with fresh-market tomato crop. The effects of the application of the sex pheromone 3E,8Z,11Z-14:Ac (from 0 to 80 g a.i./ha) were assessed on male orientation to pheromone baited traps, mating in cages and plant damage. The highest levels of interruption in male orientation (60-90%) were found in plots treated with 35 to 50 g/ha of sex pheromone. However, no treatment with pheromone was capable of significantly reducing the percentage of mined leaflets or bored fruits or the frequency of mating in cages compared to the control plots. The failure in mating disruption technique may be attributed to the composition of the synthetic pheromone, doses used, high pest population density, and mated female migration to the area treated.

Published
2000

2. Host strain specific sex pheromone variation in Spodoptera frugiperda

Author

Svatos Ales, Lorenz Sybille, Schöfl Gerhard, Marr Melanie, Groot Astrid T, and Heckel David G

Subjects
Zoology, QL1-991
Abstract

Abstract Background The fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae) consists of two distinct strains with different host plant preferences for corn and rice. To assess whether pheromonal-mediated behavioral isolation accompanies the habitat isolation on different host plants, we compared the sex pheromone composition among females of the two strains. Pheromone glands were extracted with or without injection of pheromone biosynthesis activating neuropeptide (PBAN). To assess the mode of inheritance of this variation, we also analyzed the pheromone composition of F1 hybrid females. Results Relative to intra-strain variation, the pheromone composition of the two strains differed significantly. Corn strain females contained significantly more of the second most abundant pheromone compound Z11-16:Ac (m), and significantly less of most other compounds, than rice strain females. When females were injected with PBAN before their glands were extracted, the differences between the strains were less pronounced but still statistically significant. The pheromone composition of hybrid females showed a maternal inheritance of the major component Z9-14:Ac (M) as well as of Z11-16:Ac (m). Most other compounds showed an inheritance indicating genetic dominance of the corn strain. The within-strain phenotypic correlations among the various components were consistent with their hypothesized biosynthetic pathway, and between-strain differences in the correlation structure suggested candidate genes that may explain the pheromone differences between the two strains. These include Δ9- and Δ11 desaturases, and possibly also a Δ7-desaturase, although the latter has not been identified in insects so far. Conclusion The two host strains of S. frugiperda produce systematically differing female sex pheromone blends. Previously-documented geographic variation in the sexual communication of this species did not take strain identity into account, and thus may be partly explained by different strain occurrence in different regions. The finding of pheromone differences reinforces the possibility of incipient reproductive isolation among these strains, previously shown to differ in the timing of nocturnal mating activity and host plant use. Finding the genetic basis of the pheromone differences, as well as these other biological traits, will help to elucidate the role of premating isolation in the continuing differentiation of these two strains that may eventually lead to speciation.

Published
2008
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26. Phenalenone-type phytoalexins mediate resistance of banana plants (Musa spp.) to the burrowing nematode Radopholus similis

Author

Hölscher, Dirk, Dhakshinamoorthy, Suganthagunthalam, Alexandrov, Theodore, Becker, Michael, Bretschneider, Tom, Buerkert, Andreas, Crecelius, Anna C., Waele, Dirk De, Elsen, Annemie, Heckel, David G., Heklau, Heike, Hertweck, Christian, Kai, Marco, Knop, Katrin, Krafft, Christoph, Maddula, Ravi K., Matthäus, Christian, Popp, Jürgen, Schneider, Bernd, Schubert, Ulrich S., Sikora, Richard A., Svatoš, Aleš, and Swennen, Rony L.

Published
2014

50. Proton sponge: a novel and versatile MALDI matrix for the analysis of metabolites using mass spectrometry

Author

Shroff, Rohit and Svatos, Ales

Subjects
Naphthalene -- Usage, Metabolites -- Analysis, Mass spectrometry -- Methods, Chemistry
Abstract

Here, we show the usefulness of a strong base, 1,8-bis(dimethyl-amino)naphthalene (DMAN; proton sponge), as a novel matrix for MALDI-TOF/MS analysis of anions. Several strong and weakly acidic low-molecular-weight analytes (fatty acids, amino acids, fatty acid-amino acid conjugates, plant and animal hormones, vitamins, and short peptides) were measured at physiologically relevant concentrations. Clear negative-mode MALDI-TOF/MS spectra of aH analytes using DMAN as the matrix show only deprotonated analyte signals at a low picomole/ femtomole limit-of-detection. Moreover, the spectra were totally devoid of any matrix-related signals. Standard calibration curves gave good linearity over the entire picomole range: over two concentration orders in most cases and over three orders for peptides. Using this method, the crude regurgitate of the tobacco hornworm caterpillars (Manduca sexta, Lepidoptera, Sphingidae) was analyzed. As many as 11 different components were identified from a single spot, including 16:0, 18:2, 18: 3, and 21:0 free acids and 5:0-Glu, 6:0-Glu, 18:2-Glu, 18:3-Gin, 16:0-Glu, and 16:3-Glu fatty acid-amino acid conjugates (FACs) in complete qualitative agreement with previously reported anion exchange-HPLC analyses. The identity of these components was confirmed by negative ion collision-induced dissociation (CID) [MS.sup.2] spectra.

Published
2009

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