ARS | Publication request: Update on Host Plant Resistance Studies of Banded Sunflower Moth and Sunflower Moth

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 11, 2010
Publication Date: March 11, 2010
Repository URL: http://www.sunflowernsa.com/research/research-workshop/documents/Chiru_UpdateHostPlant_10.pdf
Citation: Chirumamilla, A., Charlet, L.D., Hulke, B.S., Seiler, G.J., Gross, T.A., Knodel, J.J., Aiken, R.M. 2010. Update on Host Plant Resistance Studies of Banded Sunflower Moth and Sunflower Moth. 32nd Sunflower Research Workshop, January 13-14, 2010, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Chiru_UpdateHostPlant_10.pdf

Interpretive Summary: Insects and diseases are major constraints to crop production and breeding pest-resistance crop cultivars is one of the primary goals of crop improvement programs worldwide. Host plant resistance uses the plant's own defenses to reduce the feeding damage from pest attack. Among the insects studied, the banded sunflower moth and the sunflower head moth are the two most important seed infesting moth pests causing significant yield losses in sunflower. The first moth is more prevalent in the northern and central Plains whereas the latter is a more significant problem in the southern and central Plains. The banded sunflower moth attacks the crop at an early stage of development and larvae feed on bract tissue, florets, developing seeds and mature seeds. The sunflower moth larvae overwinter in the soil in Texas and adults are carried by northerly winds to the central and northern Plains. Female moths are attracted to and oviposit on blooming sunflower heads. Larvae feed initially on the florets and developing seeds and later destroy mature seeds. The goals of this research were to: 1) determine the mechanisms contributing to banded sunflower moth resistance in previously evaluated resistant germplasm; 2) investigate the tactile effect of trichome or plant hair density of the sunflower bracts on the ovipositional preference of the banded sunflower moth; and 3) evaluate sunflower germplasm for resistance to the sunflower moth. Our studies showed that germplasm with potential resistance to the sunflower moth is being identified. Studies determining the plant mechanisms conferring resistance to banded sunflower moth revealed that antixenosis or non-preference is likely the predominant mechanism in the three tested resistant sunflower lines and either antibiosis (adverse effect on feeding larvae) or plant tolerance (to feeding and damage) is the mechanism in the resistant check. Investigation of the role of sunflower bract trichome density in the ovipositional preference of adult banded sunflower moths is in preliminary stage and a detailed study including the potential influence of volatiles in attraction of moths to sunflower heads will be conducted in 2010.

Technical Abstract: Breeding pest-resistance crop cultivars to insects and diseases is one of the primary goals of integrated pest management programs worldwide. Host plant resistance is a tactic that uses the plant's own defenses to reduce injury from pest attack. Among the sunflower (Helianthus annuus L.) insect pests studied, the banded sunflower moth, Cochylis hospes Walsingham and the sunflower moth, Homoeosoma electellum (Hulst), are the two most important seed infesting moth pests causing significant yield losses in sunflower. The banded sunflower moth is more prevalent in the northern and central Plains whereas the sunflower moth is a more significant problem in the southern and central Plains. Cochylis hospes attacks the crop at an early stage of development and larvae feed on bract tissue, florets, developing achenes and mature seeds. Homoeosoma electellum larvae overwinter in the soil in Texas and adults migrate by northerly winds to the central and northern Plains. Female moths are attracted to and oviposit on blooming sunflower heads. Larvae feed initially on the florets and developing achenes and later destroy mature seeds. The goals of this research were to: 1) determine the mechanisms contributing to C. hospes resistance in previously evaluated resistant germplasm; 2) investigate the tactile effect of trichome density of the sunflower bracts on the ovipositional preference of the banded sunflower moth; and 3) evaluate sunflower germplasm for resistance to H. electellum. Our study showed that germplasm with potential resistance to the sunflower moth is being identified. Studies determining plant mechanisms conferring resistance to banded sunflower moth revealed that antixenosis is likely the predominant mechanism in the three tested resistant sunflower lines and either antibiosis or plant tolerance is the mechanism in the resistant check. Investigation of the role of sunflower bract trichome density in the ovipositional preference of adult C. hospes is in a preliminary stage and a detailed study including the potential influence of volatiles in attraction of moths to sunflower heads will be conducted in 2010.