Changes in protein content, peroxidase activity, and isozyme profiles in response to soybean aphid feeding were documented at V1 (fully developed leaves at unifoliate node, first trifoliate leaf unrolled) and V3 (fully developed leaf at second trifoliate node, third trifoliate leaf unrolled) stages of soybean aphid-tolerant (KS4202) and -susceptible (SD76R) soybeans. Protein content was similar...

All aphid species studied so far share the same sex pheromone components, nepetalactol and nepetalactone. Variation by different enantiomers and blends of the two components released by different aphid species are limited and can only partially explain species-specific attraction of males to females. While some host-plant odours are known to enhance specific attraction of aphid species, herbivo...

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...

The pea aphid Acyrthosiphon pisum : Harris (Hemiptera: Aphididae) is a phloem-feeding insect whose antipredator defenses include kicking, walking away, and dropping from the plant. Aphid dropping, a risky and energetically costly antipredator behavior, can be increased by the release of aphid alarm pheromone; there is also evidence that insect density and plant health can affect the likelihood ...

Background: Cucumber mosaic virus (CMV) is one of the most important viruses infecting vegetables in the fields throughout the world. Transmission efficiency of CMV could depend on the variability of virus strain but also aphid vector species and/or clones. Materials and Methods: By sequence analysis, the coat protein gene of CMV strains from different regions revealed that the CMV isolates use...

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...

Aphids are major pests in apple orchards, debilitating the crop and spreading disease. We investigated whether early-season predation by canopy spiders may be effectively controlling aphid numbers in three organic orchards. For this purpose, we monitored the aphid population dynamics from the winter eggs to colony stages and compared this to spider abundances and rates of predation on aphids de...

Background: It is generally assumed that short-term population dynamics are too slow to be influenced by evolution. Question: Can evolution occurring within only weeks (four to five generations) impact concurrent population dynamics? Organism: Green peach aphid (Myzus persicae) growing on an undomesticated host (Hirschfeldia incana). Aphid clones were collected from a single wild population. Si...

Social insects defend their own colonies and some species also protect their mutualist partners. In mutualisms with aphids, ants typically feed on honeydew produced by aphids and, in turn guard and shelter aphid colonies from insect natural enemies. Here we report that Formica podzolica ants tending milkweed aphids, Aphis asclepiadis, protect aphid colonies from lethal fungal infections caused ...

BACKGROUND The sesquiterpene (E)-ß-farnesene is the main component of the alarm pheromone system of various aphid species studied to date, including the English grain aphid, Sitobion avenae. Aphid natural enemies, such as the marmalade hoverfly Episyrphus balteatus and the multicolored Asian lady beetle Harmonia axyridis, eavesdrop on aphid chemical communication and utilize (E)-ß-farnesene as ...