In otherwise mutualistic relationships between aphids and ants, attendance by ants often has negative impacts on aphids. For example, in a previous study using traps in the field, the aphid Tuberculatus quercicola, which exhibits mutualistic interactions with ants, showed extremely low dispersal rates, despite having long wings. This study investigates whether components of the flight apparatus...

Why leaves of some trees turn red in autumn has puzzled biologists for decades, as just before leaf fall the pigments causing red coloration are newly synthesized. One idea to explain this apparently untimely investment is that red colour signals the tree's quality to herbivorous insects, particularly aphids. However, it is unclear whether red leaves are indeed less attractive to aphids than gr...

The aphid Myzus persicae displays high mortality on tobacco plants bearing a transgene which results in the accumulation of the ketosteroids cholestan-3-one and cholest-4-en-3-one in the phloem sap. To test whether the ketosteroids are the basis of the plant resistance to the aphids, M. persicae were reared on chemically-defined diets with different steroid contents at 0.1-10 µg ml(-1). Relativ...

Landscape diversification is a key element for the development of sustainable agriculture. This study explores whether the implementation of habitats for pest natural enemies enhances conservation biological control in an adjacent field. In the present study conducted in Gembloux (Belgium) in 2016, the effect of two different habitats (wildflower strips and a forest) and aphid abundance on the ...

Polyphenism, in which multiple discrete phenotypes develop from a single genotype, is considered to have contributed to the evolutionary success of aphids. Of the various polyphenisms observed in the complex life cycle of aphids, the reproductive and wing polyphenisms seen in most aphid species are conspicuous. In reproductive polyphenism, the reproductive modes can change between viviparous pa...

Trait-mediated interactions (TMII) can alter the outcome or magnitude of species interactions. We examined how the interaction between a guild of ground and rove beetles and their fly egg prey was altered by a larger predator, the ground beetle Pterostichus melanarius, and an additional prey, aphids. In field and laboratory experiments, we manipulated the presence or absence of P. melanarius an...

Ecologically important traits of insects are often affected by facultative bacterial endosymbionts. This is best studied in the pea aphid Acyrthosiphon pisum, which is frequently infected by one or more of eight facultative symbiont species. Many of these symbiont species have been shown to provide one ecological benefit, but we have little understanding of the range of effects that a single st...

Lepidopteran types of podborer and homopteran aphid insects are damaging pests of chickpea. CryIAc toxins are established control agents for podborers but do not or only slightly affect homopteran (sucking) insects. However, certain plant lectins are known for their power of killing aphids. Bioassay experiments carried out in our laboratory with lectins isolated from garlic leaves have already ...

Plant phloem sap is an extreme diet for animals, partly because of its high and variable sugar content. The physiological and feeding traits of the pea aphid Acyrthosiphon pisum that define the upper and lower limits to the range of dietary sucrose concentrations utilised by this insect were determined principally using chemically defined diets containing 0.125-1.5 mol l(-1) sucrose. On the die...

Insect populations feeding on different plant species are under selection pressure to adapt to these differences. A study integrating elements of the ecology, behavior, and gene expression of aphids on different host plants has not yet been well-explored. The present study explores the relationship between host fitness and survival, feeding behavior, and salivary gland gene expression of a pea ...