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Berkel en Rodenrijs, Netherlands

Toroitich F.J.,North West University South Africa | Ueckermann E.A.,North West University South Africa | Ueckermann E.A.,ARC Plant Protection Research Institute | Theron P.D.,North West University South Africa | And 2 more authors.
International Journal of Acarology | Year: 2011

A new spider mite species Brevinychus meshacki Toroitich and Ueckermann n. sp., collected on Philonoptera eriocalyx Harms (Schrire) from Sangasanga in Mvomero district of Tanzania, is described and illustrated. This species is distinct from the other species of this genus by having only one pair of dorsocentral setae d1 being of similar length to the dorsolateral setae, whereas the other dorsocentrals are much shorter than the dorsolateral setae. Brief notes on the two other known species Brevinychus mbandu and Brevinychus parvulus are also given. The genus characteristics of Brevinychus Meyer and a key to the species are also provided. © 2011 Copyright Taylor and Francis Group, LLC.

Guanilo A.D.,Research and Development Entomology | De Moraes G.J.,University Of So Paulo Escola Superior Of Agricultura Luiz Of Queiroz Esalq | Flechtmann C.H.W.,University Of So Paulo Escola Superior Of Agricultura Luiz Of Queiroz Esalq | Knapp M.,Koppert Biological Systems
International Journal of Acarology | Year: 2012

This is an updated checklist of phytophagous and fungivorous mites from Peru (Prostigmata: Tetranychidae, Tarsonemidae, Tenuipalpidae, Tydeidae, Eriophyidae, Diptilomiopidae; Astigmata: Acaridae, Winterschmidtiidae). The data are mainly based on an extensive survey carried out in the Peruvian territory in 2006, as well as on the new records of mites from minor collections and previous records. In addition to the new data collection, the presence of predators associated with the phytophagous mites collected is noted. © 2012 Taylor and Francis Group, LLC.

Kappers I.F.,Wageningen University | Hoogerbrugge H.,Koppert Biological Systems | Bouwmeester H.J.,Wageningen University | Dicke M.,Wageningen University
Journal of Chemical Ecology | Year: 2011

In response to herbivory by arthropods, plants emit herbivory-induced volatiles that attract carnivorous enemies of the inducing herbivores. Here, we compared the attractiveness of eight cucumber varieties (Cucumis sativus L.) to Phytoseiulus persimilis predatory mites after infestation of the plants with herbivorous spider mites (Tetranychus urticae) under greenhouse conditions. Attractiveness differed considerably, with the most attractive variety attracting twice as many predators as the least attractive variety. Chemical analysis of the volatiles released by the infested plants revealed significant differences among varieties, both in quantity and quality of the emitted blends. Comparison of the attractiveness of the varieties with the amounts of volatiles emitted indicated that the quality (composition) of the blend is more important for attraction than the amount of volatiles emitted. The amount of (E)-β-ocimene, (E,E)-TMTT, and two other, yet unidentified compounds correlated positively with the attraction of predatory mites. Quantities of four compounds negatively correlated with carnivore attraction, among them methyl salicylate, which is known to attract the predatory mite P. persimilis. The emission of methyl salicylate correlated with an unknown compound that had a negative correlation with carnivore attraction and hence could be masking the attractiveness of methyl salicylate. The results imply that the foraging success of natural enemies of pests can be enhanced by breeding for crop varieties that release specific volatiles. © 2011 The Author(s).

Pineda A.,Wageningen University | Pangesti N.,Wageningen University | Soler R.,Koppert Biological Systems | Dam N.M.,Radboud University Nijmegen | And 3 more authors.
Environmental and Experimental Botany | Year: 2016

Plants are constantly exposed to multiple biotic and abiotic stresses, such as drought and herbivory. However, plant responses to these stresses have usually been studied in isolation. Here, we take a multidisciplinary approach addressing ecological and chemical aspects of plant responses to generalist herbivores and several intensities of drought. We hypothesize that in brassicaceous plants, the effects of drought stress on herbivores can be explained by an increase in indole glucosinolates. Four-week-old Arabidopsis thaliana plants were drought stressed for one week or watered as normal. Three types of drought stress were compared: (1) no watering for 1 week and then rewatered to saturation (low drought); (2) no watering for 1 week and then rewatered to 60% of soil water content (high drought); (3) watering every other day to 60% of soil water content (continuous drought). All three types of drought stress negatively affected both the larval mass of the leaf chewer Mamestra brassicae and the population growth of the phloem feeder Myzus persicae. This was associated with increased levels of herbivore-induced indole glucosinolates compared to infested control plants. Interestingly, the levels of total indole glucosinolates did not change in uninfested plants, except for the indole 4-methoxy-glucobrassicin that was induced by continuous drought. Two-choice experiments also showed that caterpillars of M. brassicae, but not aphids, avoided drought-stressed plants only after feeding on them, but not by visual/olfactory cues. However, on a knockout mutant blocked in the production of indole glucosinolates (cyp79B2 cyp79B3), the effect of drought on herbivore performance was similar to that on wild-type plants. The results of this study show that drought stress induced higher levels of indole glucosinolates; however, these levels were not responsible for higher resistance to generalist herbivores in drought-stressed plants. © 2015 Elsevier B.V.

Cho S.-T.,Academia Sinica, Taiwan | Chang H.-H.,Academia Sinica, Taiwan | Egamberdieva D.,Leibniz Center for Agricultural Landscape Research | Kamilova F.,Koppert Biological Systems | And 3 more authors.
PLoS ONE | Year: 2015

Pseudomonas fluorescens PCL1751 is a rod-shaped Gram-negative bacterium isolated from the rhizosphere of a greenhouse-grown tomato plant in Uzbekistan. It controls several plant root diseases caused by Fusarium fungi through the mechanism of competition for nutrients and niches (CNN). This mechanism does not rely on the production of antibiotics, so it avoids the concerns of resistance development and is environmentally safe. Additionally, this bacterium promotes plant growth by alleviating salt stress for its plant host. To investigate the genetic mechanisms that may explain these observations, we determined the complete genome sequence of this bacterium, examined its gene content, and performed comparative genomics analysis with other Pseudomonas strains. The genome of P. fluorescens PCL1751 consisted of one circular chromosome that is 6,143,950 basepairs (bp) in size; no plasmid was found. The annotation included 19 rRNA, 70 tRNA, and 5,534 protein-coding genes. The gene content analysis identified a large number of genes involved in chemotaxis and motility, colonization of the rhizosphere, siderophore biosynthesis, and osmoprotectant production. In contrast, the pathways involved in the biosynthesis of phytohormones or antibiotics were not found. Comparison with other Pseudomonas genomes revealed extensive variations in their genome size and gene content. The presence and absence of secretion system genes were highly variable. As expected, the synteny conservation among strains decreased as a function of phylogenetic divergence. The integration of prophages appeared to be an important driver for genome rearrangements. The whole-genome gene content analysis of this plant growth-promoting rhizobacterium (PGPR) provided some genetic explanations to its phenotypic characteristics. The extensive and versatile substrate utilization pathways, together with the presence of many genes involved in competitive root colonization, provided further support for the finding that this strain achieves biological control of pathogens through effective competition for nutrients and niches. Copyright: © 2015 Cho et al.

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