Hormesis is a biphasic phenomenon that in toxicology is characterized by low-dose stimulation and high-dose inhibition. It has been observed in a wide range of organisms in response to many chemical stressors, including insects exposed to pesticides, with potential repercussions for agriculture and pest management. To address questions related to the nature of the dose-response and potential co...

• Certain plant species hyperaccumulate selenium (Se) to 1000 mg kg − 1 d. wt, even from low-Se soils. It is not known whether Se hyperaccumulation offers these plants any advantage. In this study the hypothesis was tested that Se can protect plants from phloem-feeding herbivores. • Indian mustard ( Brassica juncea ) grown with or without Se was subjected to colonization by green peach aphids (...

ABSTRACT A serious disease was observed in black raspberry (Rubus occidentalis) in Oregon in the last decade. Plants showing mosaic symptoms declined rapidly and, in many cases, died after several years. Double-stranded RNA extraction from symptomatic black raspberry revealed the presence of two high molecular weight bands which were cloned and sequenced. Sequence analysis disclosed the presenc...

Feeding damage to plants by insect herbivores induces the production of plant volatiles, which are attractive to the herbivores natural enemies. Little is understood about the plant biochemical pathways involved in aphid-induced plant volatile production. The aphid parasitoid Diaeretiella rapae can detect and respond to aphid-induced volatiles produced by Arabidopsis thaliana. When given experi...

Recent aphid-vectored viruses in the northeastern U.S. led to extensive surveys of aphid (Hemiptera: Aphididae) species composition. We report the species composition and richness of alate aphids associated with processing snap bean (Phaseolus vulgaris L.; Fabales: Fabaceae) agroecosystems from field surveys conducted during 5 yr in New York and 3 yr in Pennsylvania. Rates of species accumulati...

1 Altered atmospheric composition, associated with climate change, can modify herbivore population dynamics through CO2 and/or O3-mediated changes in plant quality. 2 Although pea aphid Acyrthosiphon pisum genotypes exhibit intraspecific variation in population growth in response to atmospheric composition, the proximate mechanisms underlying this variation are largely unknown. 3 By rearing sin...

The effect of dark-induced senescence on Solanum tuberosum L. (Solanales: Solanaceae) plants was assessed on the feeding behavior and performance of the green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae). Senescence was induced by covering the basal part of the plant with a black cloth for 5 d, avoiding the light passage, but keeping the apical buds uncovered. The basal part of con...