Biocontrol Science and Technology (2012) 22, 1221-1233

Jeffrey Gardner, Mark G. Wright, Thomas Peter Kuhar, Sylvie Anni Pitcher and Michael Peter Hoffmann (2012)
Dispersal of Trichogramma ostriniae in field corn
Biocontrol Science and Technology 22 (10), 1221-1233
Abstract: Trichogramma ostriniae has shown success as a biological control agent for European corn borer (Ostrinia nubilalis) in sweet corn and the species offers potential for suppression of lepidopteran pests of field corn. Field corn is typically planted at higher densities, is taller, and has greater leaf area than sweet corn, presenting a possible restriction on T. ostriniae dispersal and efficacy. Therefore, parasitoid dispersal in field corn from the centre of a 6.25 ha square grid was determined using sticky cards to capture adult T. ostriniae and sentinel eggs of O. nubilalis to monitor parasitism after releases of ~1 million of T. ostriniae each into four fields of corn. Dispersal was rapid and extensive, achieving distances of ~175 m within 4-7 days after release. The pattern of movement fit well with a diffusion model of dispersal, with the greatest level of dispersal occurring from 7 to 10 days post-release. Parasitism of O. nubilalis sentinel egg masses declined linearly with distance from the release foci, and was also greatest 7-10 days post-release. However, measurement of association showed no significant differences between the spatial distributions of sticky trap captures and percentage parasitism of O. nubilalis egg masses. The distances from the release point that encompassed 98% of re-captured T. ostriniae increased over time and were estimated to range from a low of 100 m at 4 days post-release to 365 m at 14 days post-release. The results of this research suggest that T. ostriniae relies initially on random movement to locate host patches, and that a single release locus per hectare would be sufficient in field corn.
(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): Thomas P. Kuhar, Mark G. Wright

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
transmission/dispersal

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ostrinia nubilalis	Maize/corn (Zea mays)
Trichogramma ostriniae (parasitoid)	Ostrinia nubilalis	Maize/corn (Zea mays)