Does insecticide application in a winter oilseed rape field influence the abundance of pollen beetle Meligethes aeneus in nearby ornamental flowers and vegetables?
Correspondence to: Inger Åhman, Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Box 101, SE-230 53 Alnarp, Sweden. E-mail: Inger.Ahman@slu.se
Pollen beetle is a pest that attacks oilseed rape as well as many other brassicaceous crops, garden vegetables and ornamental flowers. The present study was primarily carried out to investigate whether insecticide application in brassicaceous field crops might influence the abundance of pollen beetles in nearby private garden flowers and vegetables.
At peak emergence of the new generation of pollen beetles, a significantly higher number of beetles were found in flowers, and in window traps, alongside untreated as opposed to alongside treated sections of the winter oilseed rape (WOSR) field. However, the type of flower played a role in the number of pollen beetles found in the flowers. The presence of pollen beetles in both ornamental and wild flowers was also significantly influenced by the direction of placement of the flowers. No pollen beetle, neither overwintering nor newly emerged, was observed in any of the brassicaceous vegetables placed along the field.
The number of pollen beetles in the WOSR field strongly influenced the number of pollen beetles in nearby flowers of preference to the beetles, and insecticide treatment with Biscaya (thiacloprid) against pollen beetle in oilseed rape may thus help, indirectly, to protect nearby garden flowers from damage. © 2013 Society of Chemical Industry