International Journal of Pest Management (2011) 57, 329-339

Tessa R. Grasswitz and David James (2011)
Phenology and impact of natural enemies associated with the hop looper (Hypena humuli) in Washington State, USA
International Journal of Pest Management 57 (4), 329-339
Abstract: The hop looper, Hypena humuli Harris (Lepidoptera: Noctuidae), is becoming an increasingly important pest of hops (Humulus lupulus L.) (Rosales: Cannabaceae) in western USA. Currently, control of this pest usually involves broad-spectrum pesticides that kill natural enemies and disrupt biological control of other hop pests. In order to develop better management strategies for H. humuli, field and laboratory studies were conducted over a four-year period to identify the pest's natural enemies and to investigate their phenologies and to assess their impact. Nine parasitoid species and assorted species of invertebrate predator were found to attack different life-stages of H. humuli. Levels of parasitism were consistently low throughout the study period and none of the parasitoids found was a specialist natural enemy of the pests. Exclusion cage studies showed, however, that the complex of natural enemies as a whole can significantly reduce larval densities of the pest, and laboratory studies confirmed successful predation of H. humuli larvae by several generalist predators including the European earwig (Forficula auricularia L.), the damsel bug Nabis alternatus Parshley and two species of the geocorid bug genus Geocoris.
(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): Tessa R. Grasswitz

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Hypena humuli	Hop (Humulus lupulus)	U.S.A. (NW)
Forficula auricularia (predator)	Hypena humuli
Nabis alternatus (predator)	Hypena humuli