Lesser peachtree borer (Lepidoptera: Sesiidae) oviposition on Prunus germplasm

The lesser peachtree borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sesiidae), is a serious pest of peach, Prunus persica (L.) Batsch, across the southeastern United States. We examined oviposition by S. pictipes on field-grown Prunus scion and rootstock cultivars and two endemic Prunus spp. when sawn limbs, not roots, were assayed in the laboratory. A choice test compared oviposition on the peach scion 'Harvester', peach rootstock 'Guardian', plum×peach hybrid rootstock 'MP-29', and the plum hybrid rootstock 'Sharpe'. A significantly lower percentage of eggs occurred on limbs of Sharpe rootstock than other choices. A choice test using two endemic hosts, black cherry (P. serotina Ehrh.) and Chickasaw plum (P. angustifolia Marsh.), along with Sharpe rootstock, found a lower percentage of eggs on limbs of Sharpe than either endemic host. However, when only limbs of Sharpe and a decoy were used, almost all eggs were laid on Sharpe. Interestingly, when Harvester and Sharpe limbs were paired side by side, a higher percentage of eggs were recovered from the Harvester limb than from the Sharpe limb. An analysis of volatiles from Sharpe may identify why fewer eggs were laid on it. Because S. pictipes attacks host trees above ground and Sharpe rootstock on grafted trees grows below ground, this rootstock might be a management option against the congeneric, root-attacking peachtree borer, S. exitiosa (Say). Our results suggest that high budding a peach scion onto Sharpe rootstock, thus allowing the rootstock to serve as the trunk, warrants further investigation against S. exitiosa under orchard conditions.