Journal of Economic Entomology (2018) 111, 2053-2058

Pooria Ensafi, David W. Crowder, Aaron D. Esser, Zhiguo Zhao, Juliet M. Marshall and Arash Rashed (2018)
Soil type mediates the effectiveness of biological control against Limonius californicus (Coleoptera: Elateridae)
Journal of Economic Entomology 111 (5), 2053-2058
Abstract: Wireworms, the larval stage of click beetles (Coleoptera: Elateridae), are a considerable threat to cereal and vegetable production in the Pacific Northwest and Intermountain regions of the United States. As insecticides are generally ineffective, alternative controls are needed to improve wireworm management. Wireworms are continuously exposed to a wide range of subterranean pathogenic organisms in the soil; identifying these organisms and determining their impact would contribute to the development of biological control for wireworms. Here, we evaluated the efficacy of an entomopathogenic nematode, Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), and a fungus, Metarhizium brunneum Petch (strain F52) (Hypocreales: Clavicipitaceae), for control of the Pacific Northwest predominant wireworm species Limonius californicus, in two different soil media. We also examined whether diatomaceous earth (DE) increases the efficacy of entomopathogens through facilitating their penetration into the host integument. Treatments containing M. brunneum (F52) resulted in the highest rates of wireworm mortality, indicating that the fungus may be more effective than the nematode at reducing population size. However, results were impacted by soil media. In peatmoss-dominated medium, M. brunneum-containing treatments were more effective in reducing feeding damage than treatments containing S. carpocapsae. However, in sand-dominated medium, treatments with S. carpocapsae provided relatively better seedling protection. No consistent effect of DE was detected. Our results suggest that the effectiveness of wireworm biological control agents depends on soil media, such that the application of biological control against wireworms must be made with knowledge of field soil type.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Arash Rashed, David W. Crowder, Aaron D. Esser

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Limonius californicus
Steinernema carpocapsae/Xenorhabdus nematophila (entomopathogen)	Limonius californicus
Metarhizium brunneum (entomopathogen)	Limonius californicus