Nearly 25 years ago, Ellstrand & Roose (1987) reviewed what was known at the time of the genetic structure of clonal plant species. What is the relationship between space and clonal fitness, they asked. What is the best way for a clone to grow within its ecological neighbourhood? The pot had been stirred 10 years previously by Janzen (1977), who pointed out how little we know about the populati...

Medicago truncatula is attacked by a broad range of insect herbivores including sieve-element feeders, cell content feeders, and chewing insects. In M. truncatula, genetic resistance against insects has to date been identified only against aphids: single dominant resistance genes have been identified conferring resistance against the pea aphid, bluegreen aphid, and spotted alfalfa aphid. Aphids...

understanding of parameters that influence parasitoids fitness is necessary for mass rearing and effective use of parasitoids. host quality is an intrinsic feature that is determined by quantitative and qualitative differences in hosts. these differences can change nutritional resources available and consequently affect life history traits of parasitoid. in this study, parasitoid wasps lysiphle...

Many aphids are known to engage in a trophic mutualism with ants, whereby the aphids secrete sugary-rich honeydew which is collected by the ants for food, and the ants, in exchange, protect the aphids against natural enemies. Previous results, however, suggest that the production of some of the honeydew sugars, such as the ant-attractant trisaccharide melezitose, may induce an indirect cost to ...

Prey selection was assumed to be a vital strategy to maximize the fitness of predators. Visual cues are important for predators to locate a prey, and several species of lady beetles have been reported to prefer the red morph pea aphid Acyrthosiphon pisum rather than the green morph in empty containers with different colors. However, the preference of a predator on the red and green color morphs...

Materials and methods Samples of A. pisum were collected from natural populations on vetch or white clover, preserved in acetone, and subjected to DNA extraction individually. At each locality, 20 aphids were subjected to specific PCR detection of the endosymbionts as described (S1). The aphid strain TUt, naturally infected with PAUS, was derived from a parthenogenetic female collected on white...