BioControl (2015) 60, 783-793

Sergio Pérez-Guerrero, Asnake Gelan-Begna and Enrique Vargas-Osuna (2015)
Compatibility of Orius laevigatus and Cheiracanthium pelasgicum for predation on Helicoverpa armigera eggs: effects of density and day/night activity on intraguild predation
BioControl 60 (6), 783-793
Abstract: Intraguild predation (IGP) among predatory arthropods can impair pest control efforts and endanger the joint-action compatibility of groups of natural enemies. The present study used plant microcosms to examine IGP of Cheiracanthium pelasgicum (C. L. Koch) (Araneae: Miturgidae) on minute pirate bugs Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), two of the major lepidopteran-egg predators in southern Spanish cotton fields, and its effects on the control of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) eggs. Intensive unidirectional IGP of C. pelasgicum on O. laevigatus was observed under plant arena conditions: over 90 % of minute bugs were killed by spiders in the first 24 h. However, no negative interaction between C. pelasgicum and minute pirate bugs was found under different egg-density conditions with Orius alone, and the combination of two predator treatments displayed significantly higher predation rates than the spider-alone treatment after 24 h. Increased egg density did not affect control by predators, nor did it prompt a significant reduction in IGP. During a day–night bioassay, negative interaction between the two predators was found under night conditions, impacting on egg predation rates due to the combination of two predators. Predation of spiders on H. armigera eggs took place mainly at night, while predation by minute bugs was recorded both by day and by night. Finally, IGP by C. pelasgicum on minute pirate bugs was significantly higher by night. These outcomes demonstrate that diurnal and more intensive nocturnal IGP by spiders on minute pirate bugs had a moderate impact on the early control of H. armigera, with no negative effects after 24 h.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera	Cotton (Gossypium)	Spain (continental)
Orius laevigatus (predator)	Helicoverpa armigera	Cotton (Gossypium)	Spain (continental)
Cheiracanthium pelasgicum (predator)	Helicoverpa armigera	Cotton (Gossypium)	Spain (continental)