TY - JOUR

T1 - Cabbage whiteflies colonise Brassica vegetables primarily from distant, upwind source habitats

AU - Ludwig, Martin

AU - Ludwig, Hella

AU - Conrad, Christopher

AU - Dahms, Thorsten

AU - Meyhöfer, Rainer

N1 - Funding Information: We thank the owners and staff of the 18 horticultural ‘Bioland’ farms for taking part in this study and for supporting us, as well as André Brun, Sergej Gulidov, Seraphine Herrmann, Patrick Knöfel, Robert Lessing, Timo Michel, Nils Plump, Hans‐Joachim Seelbinder, Florian Vogt, Anna Walter, and Wael Yakti for their help in the field and laboratory, and Péter Batáry, Sebastian Fritsch, Hans‐Michael Poehling, Sylvia Seissiger, and anonymous reviewers for advice. We further thank our project partners at the Julius Kühn‐Institute for providing the ATKIS maps. This research is part of the ‘BMBF‐AgroClustEr: WeGa‐Kompetenznetz Gartenbau’ and was funded by the ‘Bundesministerium für Bildung und Forschung’ (grant 0315542A). The authors declare that they have no conflict of interest.

PY - 2019/9/5

Y1 - 2019/9/5

N2 - The occurrence of species in rapidly changing environments, such as agricultural landscapes, is affected by their ability to recolonise habitats. Knowledge of the landscape scale affecting colonisation is essential for large-scale pest management. Colonisation by insects can be affected on multiple landscape scales, as different morphs of a species may have specific dispersal abilities. The cabbage whitefly, Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae), a major pest of Brassica vegetables, is known to colonise Brassica vegetables primarily from fields of oilseed rape, Brassica napus L. (Brassicaceae). We used field mapping and remote sensing to characterise the relevant scales for colonisation of Brussels sprouts by cabbage whiteflies. Surprisingly, oilseed rape fields in wide landscapes (2–8 km around study sites) explained colonisation better than oilseed rape areas in local landscapes (200–1 000 m around study sites). The explained variance increased when additional weight was given to upwind source habitats, indicating wind transport of whitefly colonisers. Low importance of local compared to wide landscape source habitats can be explained by the flight behaviour of whitefly morphs. Migratory morphs show phototactic attraction but are attracted by hosts only during the later phases of flight. Therefore, they ignore host plants close to their origin and disperse several kilometres. Trivial flight morphs rarely move more than a few hundred metres. In conclusion, as most whitefly colonisers reached Brassica vegetables from source habitats at a distance of 2–8 km, predictions on pest pressure and landscape-scale whitefly management should consider these distances. In contrast, oilseed rape fields in the local landscape, which usually worry farmers, had little effect.

AB - The occurrence of species in rapidly changing environments, such as agricultural landscapes, is affected by their ability to recolonise habitats. Knowledge of the landscape scale affecting colonisation is essential for large-scale pest management. Colonisation by insects can be affected on multiple landscape scales, as different morphs of a species may have specific dispersal abilities. The cabbage whitefly, Aleyrodes proletella (L.) (Hemiptera: Aleyrodidae), a major pest of Brassica vegetables, is known to colonise Brassica vegetables primarily from fields of oilseed rape, Brassica napus L. (Brassicaceae). We used field mapping and remote sensing to characterise the relevant scales for colonisation of Brussels sprouts by cabbage whiteflies. Surprisingly, oilseed rape fields in wide landscapes (2–8 km around study sites) explained colonisation better than oilseed rape areas in local landscapes (200–1 000 m around study sites). The explained variance increased when additional weight was given to upwind source habitats, indicating wind transport of whitefly colonisers. Low importance of local compared to wide landscape source habitats can be explained by the flight behaviour of whitefly morphs. Migratory morphs show phototactic attraction but are attracted by hosts only during the later phases of flight. Therefore, they ignore host plants close to their origin and disperse several kilometres. Trivial flight morphs rarely move more than a few hundred metres. In conclusion, as most whitefly colonisers reached Brassica vegetables from source habitats at a distance of 2–8 km, predictions on pest pressure and landscape-scale whitefly management should consider these distances. In contrast, oilseed rape fields in the local landscape, which usually worry farmers, had little effect.

KW - Aleyrodes proletella

KW - Aleyrodidae

KW - Brassicaceae

KW - Hemiptera

KW - landscape-scale pest management

KW - oilseed rape

KW - remote sensing

KW - satellite image

KW - spillover

KW - wind dispersal

UR - http://www.scopus.com/inward/record.url?scp=85070995082&partnerID=8YFLogxK

U2 - 10.1111/eea.12827

DO - 10.1111/eea.12827

M3 - Article

AN - SCOPUS:85070995082

VL - 167

SP - 713

EP - 721

JO - Entomologia Experimentalis et Applicata

JF - Entomologia Experimentalis et Applicata

SN - 0013-8703

IS - 8

ER -