| aphid species--vectors of plum pox virus. | plum pox virus (ppv) is widely spread by natural vectors present in plum orchards. the efficiency of transmission is dependent on the frequency of the occurrence of vectors and the cultivar susceptibility to this pathogen. having in view that ppv has a wide range of annual and multiannual host plants and vectors, there is great concern for obtaining ppv-resistant cultivars. this report deals with the following vectors: hyalopterus pruni, brachycaudus cardui, brachycaudus helichrysi. myzus persic ... | 1998 | 10073225 |
| host specialization of parasitoids and their hyperparasitoids on a pair of syntopic aphid species. | parasitoids of herbivorous insects have frequently evolved specialized lineages exploiting hosts occurring on different plants. this study investigated whether host specialization is also observed when closely related parasitoids exploit herbivorous hosts sharing the same host plant. the question was addressed in economically relevant aphid parasitoids of the lysiphlebus fabarum group. they exploit two aphid species (aphis fabae cirsiiacanthoides and brachycaudus cardui), co-occurring in mixed c ... | 2013 | 23480317 |
| ant-aphid mutualisms: the impact of honeydew production and honeydew sugar composition on ant preferences. | the honeydew composition and production of four aphid species feeding on tanacetum vulgare, and mutualistic relationships with the ant lasius niger were studied. in honeydew of metopeurum fuscoviride and brachycaudus cardui, xylose, glucose, fructose, sucrose, maltose, melezitose, and raffinose were detected. the proportion of trisaccharides (melezitose, raffinose) ranged between 20% and 35%. no trisaccharides were found in honeydew of aphis fabae, and honeydew of macrosiphoniella tanacetaria co ... | 1999 | 28307416 |
| predators and mutualists influence the exclusion of aphid species from natural communities. | we investigated why two species of aphids (aphis jacobaeae and brachycaudus cardui) were very rare in a study site despite their abundance in the surrounding area. the study site contained many common species of aphid and we tested the hypothesis that the community of aphid predators in the field excluded the missing species. colonies of the two aphid species were artificially initiated in the experimental site and allocated to one of four treatments: control; ground predator exclusion; total pr ... | 1999 | 28308151 |