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Effects of land use on infestation and parasitism rates of cabbage seed weevil in oilseed rape
Author(s) -
Kovács Gabriella,
Kaasik Riina,
Lof Marjolein E,
van der Werf Wopke,
Kaart Tanel,
Holland John M,
Luik Anne,
Veromann Eve
Publication year - 2019
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.5161
Subject(s) - herbaceous plant , infestation , biology , agronomy , parasitism , grassland , weevil , pest analysis , habitat , biological pest control , ecology , botany , host (biology)
BACKGROUND This study investigated how infestation rates of an important oilseed rape pest, the cabbage seed weevil ( Ceutorhynchus obstrictus ) and rates of parasitization by its parasitoids are affected by land use, up to 1000 m from 18 focal fields. RESULTS The mean proportion of C . obstrictus ‐infested pods per plant was 8% (2–19.5%). Infestation rates were higher if the adjacent habitat was a herbaceous semi‐natural habitat than if it was either another crop or a woody habitat. Infestation rates were positively related to the area of herbaceous semi‐natural vegetation, permanent grassland and wheat (which followed oilseed rape in the crop rotation) at a spatial scale of at least 1 km. The mean parasitism rate of C . obstrictus larvae was 55% (8.3–87%), sufficient to provide efficient biocontrol. Parasitism rates were unrelated to adjacent habitats, however, they were positively related to the presence of herbaceous linear elements in the landscape and negatively related to permanent grasslands at a spatial scale of 200 m. CONCLUSION Proximity of herbaceous elements increased both infestation rates and parasitism, while infestation was also related to landscape factors at larger distances. The findings provide an empirical basis for designing landscapes that suppress C . obstrictus , at both field and landscape scales. © 2018 Society of Chemical Industry