the toxicity of thiamethoxam and pirimicarb on diaeretiella rapae (mc'intosh) as a parasitoid of lipaphis erysimi (kaltenbach), exposed to residues on glass vials, was investigated under laboratory conditions at 23 ± 2 °c, 70 ± 5% rh and 16:8 h (l: d). moreover, in order to find the negative impacts of both insecticides on the efficiency of d. rapae, the functional response of the exposed paras...

Clonal diversity in asexual populations may be maintained if different clones are favoured under different environmental conditions. For aphids, parasitoids are an important variable of the biotic environment. To test whether parasitoids can mediate selection among host clones, we used experimental populations consisting of 10 clones of the peach-potato aphid, Myzus persicae, and allowed them t...

It is of adaptive value for a plant to prepare its defenses when a threat is detected, and certain plant volatiles associated with insect damage, such as cis-jasmone (CJ), are known to switch-on defense metabolism. We used aphid and aphid parasitoid responses to Arabidopsis thaliana as a model system for studying gene expression and defense chemistry and its impact at different trophic levels. ...

Plants are commonly exposed to abiotic and biotic stresses. We used 350 Arabidopsis thaliana accessions grown under controlled conditions. We employed genome-wide association analysis to investigate the genetic architecture and underlying loci involved in genetic variation in resistance to: two specialist insect herbivores, Pieris rapae and Plutella xylostella; and combinations of stresses, i.e...

Heterosubspecific mating experiments were carried out between two subspecies of cabbage butterflies, British Pieris rapae rapae and Japanese P. rapae crucivora, to examine how accurately males recognize the mates. The two subspecies are different in that the wings of female P. rapae rapae reflect little UV light, whereas those of female P. rapae crucivora are strongly UV-reflective. The wing co...

An enzyme-linked immunosorbent assay (ELISA) was developed to detect remains of Pieris rapae L. (Lepidoptera: Pieridae) immature stages in the guts of field collected arthropod predators. The assay can be used to help ascertain the relative importance of arthropod predator species in suppressing P. rapae in cabbage, Brassica oleracea var. capitata L. The ELISA is sensitive to all immature stage...