EFFECTS OF FEEDING BY 2 FOLIVOROUS ARTHROPODS ON SUSCEPTIBILITY OF HYBRID POPLAR CLONES TO A FOLIAR PATHOGEN

We investigated variation in folivore-induced effects on subsequent pl ant suitability to a foliar pathogen. We used a leaf disk assay to exp ose three clones of hybrid poplar, NC11382, NE332 and NM6, to coloniza tion by a leaf spot pathogen, Septoria musiva. Undamaged leaf disks of NE332 were the most resistant to S. musiva, followed by NM6 and NC113 82, respectively. To test the effects of prior herbivory on subsequent susceptibility to this fungal pathogen, we inoculated S. musiva on le af disks taken from leaves which had been exposed to feeding by Tetran ychus mites or cottonwood leaf beetles. Prior activity by mites and co ttonwood leaf beetle affected the subsequent susceptibility of clones NC 11382 and NE332 to S. musiva.