Entomologia Experimentalis et Applicata (2011) 138, 256-262

Sandra Öberg, Anna Cassel-Lundhagen and Barbara Ekbom (2011)
Pollen beetles are consumed by ground- and foliage-dwelling spiders in winter oilseed rape
Entomologia Experimentalis et Applicata 138 (3), 256-262
Abstract: Pollen beetles, Meligethes aeneus (Fabricius) (Coleoptera: Nitidulidae), are major pests in oilseed rape (OSR), Brassica napus L. (Brassicaceae). Among the predator species in the generalist predator complex present in OSR fields, wolf spiders (Araneae: Lycosidae) are found on the ground and cobweb spiders (Araneae: Theridiidae) build webs in the foliage. Here we study the incidence of predation of pollen beetles by these two spider groups using DNA-based molecular analysis. Wolf spiders of the genus Pardosa and the cobweb spider, Theridion impressum L. Koch, were each collected in three winter OSR fields over a period of about 3 weeks. Pollen beetle densities as well as the occurrence of predators and alternative prey were monitored. In total, 13.8% of the collected Pardosa spp. tested positive for pollen beetle DNA in the PCR analyses, whereas 51.7%T. impressum were positive. The likelihood of detecting pollen beetle DNA in the gut contents of both spider groups was positively related to pollen beetle larval density. The implications of these results for conservation biological control and future studies of food webs in OSR are discussed.
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Link to article at publishers website
Database assignments for author(s): Anna Cassel-Lundhagen, Sandra Öberg

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
surveys/distribution/isolation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Brassicogethes aeneus	Rape/canola (Brassica napus)
Pardosa (genus - predators)	Brassicogethes aeneus	Rape/canola (Brassica napus)
Phylloneta impressa (predator)	Brassicogethes aeneus	Rape/canola (Brassica napus)