Recently it was discovered that ovipositing Hessian fly females can detect if a susceptible wheat seedling has already been attacked by Hessian fly larvae. Plants occupied by larvae for 1, 6 and 10 days received progressively fewer Hessian fly eggs. We extended these studies to wheat plants that express major resistance genes. Ovipositing Hessian fly females are unable to detect plants carrying major resistance genes and therefore, when plants are unoccupied, oviposit similar numbers of eggs on susceptible and resistant plants. While plants expressing any of the known major resistance genes cause the death of neonate Hessian fly larvae, plants expressing different resistance genes appear to defend themselves in somewhat different ways. To test whether Hessian fly females can detect when a resistant plant is defending itself against attack by Hessian fly larvae, we used a susceptible control genotype and two resistant genotypes expressing different resistance genes and compared the numbers of eggs oviposited on unoccupied plants and plants attacked by Hessian fly neonate larvae 1, 2, 3, 6, 10 and 14 days prior to the test.
Species 1: Diptera Cecidomyiidae Mayetiola destructor (Hessian fly)
Keywords: resistance genes, host selection
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