Plant genotypes are known to affect performance of insect herbivores and the community structure of both herbivores and higher trophic levels. Still, only a limited number of studies demonstrate differences in the performance of predators and parasitoids because of plant genotypic effects and most of these focus on gall formers. We designed a greenhouse experiment to investigate the effects of ...

BACKGROUND Many inducible plant-defense responses are activated by jasmonates (JAs), C(6)-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS) and hydroperoxide lyase (HPL) branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial ove...

We extend the sharp version of the Chabauty-Coleman bound on the number of rational points on a curve of genus g ≥ 2 to the case of bad reduction.

abstract the aphid parasitoids, aphidius colemnai viereck and a. matricariae (haliday) (hymenoptera: braconidae: aphidiinae) have high potential as the most effective biological control agents for controlling the cotton aphis aphis gossypii glover (hemiptera: aphididae). in this investigation, the effect of five constant temperatures (10, 15, 20, 25 and 30 °c) on the reproductive parameters was...

Die keuring van studentverpleegsters skep spesifieke probleme vir verpleegadministrateurs en skoolprestasie skyn een van die min objektiewe keurmiddels te wees. Die resultate van hierdie studie toon dat daar wel beduidende verskille bestaan met betrekking tot prestasie in skoolvakke tussen studente wat hul opleiding voltooi het en die wat hul opieiding gestaak het. Kosteimplikasies van kortdien...

The aphid parasitoid Aphidius rhopalosiphi is the most abundant species of Aphidiinae in cereal fields in northern Europe. Although the larval morphology of other Aphidiinae has been described, the morphology and immature development of A. rhopalosiphi remain unknown. Our goal is to relate growth and larval developmental stages to morphological changes during parasitoid development, using light...

The presence of nonprey or nonhosts is known to reduce the strength of consumer- resource interactions by increasing the consumer's effort needed to find its resource. These interference effects can have a stabilizing effect on consumer-resource dynamics, but have also been invoked to explain parasitoid extinctions. To understand how nonhosts affect parasitoids, we manipulated the density and d...

During parasitoid development, the immature parasitoid is confined to the host species. As a result, any potential to modify the physiology or behaviour of the host could play an important role in parasitoid fitness. The potential for host manipulation by the aphid parasitoid Aphidius avenae to increase cold thermotolerance was investigated using the aphid host species Metopolophium dirhodum an...