REDIA (2009) 92, 159-162
C.A. Dedryver, V. Fiévet, M. Plantegenest and A. Vialatte (2009)
An overview of the functioning of Sitobion avenae populations at three spatial scales in France
REDIA 92, 159-162
Abstract: In this paper we give 3 snapshots of our recent work on S. avenae at field, landscape and country scales. From April to June wheat fields are continuously colonized by winged S. avenae and previously established colonies experience high extinction rates. This leads to changes in spatial distribution of aggregates of aphids and to a progressive spatial homogenisation of the populations in fields, and highlights the role of spring immigrants in the field dynamics of S. avenae. In the surrounding landscape, the S. avenae populations on cultivated cereals (wheat, maize, barley) do not differ genetically. Conversely, aphids from weed margins and pastures (mostly on Poeae) clearly differ from those on cereals, indicating a low level of gene flow between the 'uncultivated' (mostly perennial) and cultivated system (annual). Consequently weeds and pasture grasses are probably poor sources of S. avenae for further infestation of cereal fields. The role of surrounding crops and weeds as a source of aphids infesting wheat was assessed by stable isotopic ratios and population genetic tools. In autumn, up to the beginning of October, most S. avenae landing on wheat originated from maize and after this from cereal volunteers. In spring the influx from surrounding cereal volunteers varied between years, but uncultivated Poeae played a minor role. At country scale on cereals, clonal reproduction and parthenogenetic overwintering prevails everywhere in France, but there is a trend toward increasing sexuality northward. The weak genetic differentiation of the regional populations on cereals and the presence of many identical genotypes in most of the regions sampled confirm the high dispersal ability of S. avenae. The high occurrence of widespread genotypes in multiple copies, belonging to the same genetic pool, which persist over several years in France and other countries in Europe, indicates a homogenising effect of selection by millions of hectares of cereals.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Charles-Antoine Dedryver
Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Sitobion avenae | Barley (Hordeum vulgare) | France | ||
| Sitobion avenae | Maize/corn (Zea mays) | France | ||
| Sitobion avenae | Wheat (Triticum) | France |
