Pest Management Science (2020) 76, 3657-3666

Ana M. Camargo, María Arias-Martín, Pedro Castañera and Gema P. Farinós (2020)
Performance of Sesamia nonagrioides on cultivated and wild host plants: Implications for Bt maize resistance management
Pest Management Science 76 (11), 3657-3666
Abstract:
BACKGROUND
Sesamia nonagrioides is an important maize pest in the Mediterranean basin that is effectively controlled by Cry1Ab-expressing maize (Bt maize). The continued cultivation of Bt maize in Spain exerts high selection pressure on the target pests, which could lead to the development of resistance. Provision of refuges of non-Bt plants is an essential component in the high-dose/refuge (HDR) strategy to delay resistance evolution. Here we analyze the suitability of cultivated (rice and sorghum) and wild (Johnsongrass, cattail, common reed and giant reed) plants, reported as hosts of S. nonagrioides, for larval development and oviposition of this pest compared to maize, and we evaluate their potential role in delaying resistance development to Bt maize.
RESULTS
Bioassays conducted with plant pieces or whole plants showed that the larval cycle could only be completed in the three cultivated plants and in Johnsongrass. Females showed a strong preference for ovipositing on maize in comparison with sorghum or rice. Although young larvae consumed more sorghum than maize in two-choice bioassays, both larvae and adults had a better performance (shorter larval period and higher pupal weight, fecundity and fertility) when larvae fed on maize throughout their larval stage than when they fed on sorghum or rice.
CONCLUSION
None of the alternative hosts of S. nonagrioides tested here should be considered as natural unstructured refuges within the HDR strategy for Bt maize and this pest in Spain, as some of the necessary requirements to fulfill this strategy would not be met.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Pedro Castañera

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sesamia nonagrioides	Maize/corn (Zea mays)	Spain (continental)
Bacillus thuringiensis Cry1A-toxin (entomopathogen)	Sesamia nonagrioides		Spain (continental)