For the enhancement of cultural control, the agricultural practices such as intercropping can profoundly affect the insect pest populations. Studies were undertaken to examine the effects of intercropping wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) with canola (Brassica napus L.) on the incidence of aphid (Hemiptera: Aphididae) population and related crop yield. Study observed ...

BACKGROUND AND AIMS Plants modulate defence signalling networks in response to different biotic stresses. The present study evaluated the effect of a phloem-sucking aphid on plant defence mechanisms in pepper (Capsicum annuum) during subsequent pathogen attacks on leaves and rhizosphere bacteria on roots. METHODS Plants were pretreated with aphids and/or the chemical trigger benzothiadiazol (...

Although soybean aphid (Aphis glycines) resistance is commercially available in the form of the Rag1 gene, the mechanism of this resistance is not fully understood. Amino acids are a limiting factor for aphid growth, and there is evidence that plant amino acid composition is related to aphid resistance. Antibiotic resistance like that conferred by Rag1 could be associated in part with both prot...

Effectiveness of different doses of neem extracts and a synthetic organic insecticide against mustard aphid was studied in the experimental farm of the Oilseed Research Centre, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur, during two consecutive years 2010-2011 and 2011-2012 for the control of mustard aphid. Eight treatments were evaluated against mustard aphid under fi...

Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A recent study highlighted the role of bacterial ...

in this research, population fluctuation of canola aphids and their natural enemies were investigated during 2007-2008. random samples of 50 plants were taken twice a week. mustard aphid (lipaphis erysimi kalt.), green peach aphid(myzus persicae sulzer)and cabbage aphid (brevicoryne brassicae l.) were recorded on canola. however,the mustard aphid with relative frequency of 79% was dominant. the...

A method to simulate orthotropic behaviour in thin shell finite elements is proposed. The approach is based on the transformation of shape function derivatives, resulting in a new orthogonal basis aligned to a specified preferred direction for all elements. This transformation is carried out solely in the undeformed state leaving minimal additional impact on the computational effort expended to...

When a stiff film on a soft substrate is compressed, the surface of the film forms wrinkles, with tunable wavelengths and amplitudes that enable a variety of applications. As the compressive strain increases, the film undergoes post-wrinkling bifurcations, leading to period doubling and eventually to formation of localized folds or ridges. Here we study the post-wrinkling bifurcations in films ...