Resumen de Hot water immersion as a disinfestation treatment for grapevine root cuttings against genetically diverse grape phylloxera Daktulosphaira vitifoliae Fitch
C.W. Clarke, S. Norng, B.M. Carmody, D. Yuanpeng, K. S. Powell
Background and Aims Grape phylloxera, Daktulosphaira vitifoliae Fitch, is an important biosecurity pest in Australia. As part of a management strategy, movement of grapevine cuttings, rootlings and propagation material must comply with the National Phylloxera Management Protocols which recommend a hot water treatment. This study validated the effectiveness of the protocol against genetically diverse phylloxera strains and developmental stages.
Methods and Results Excised roots of Vitis vinifera L. infested with first instars of phylloxera G1, G4, G7, G19, G20 and G30 genetic strains, and eggs, intermediates and adult stages of G4 were immersed in water for 5 and 30 min at 22, 40, 45, 50 and 54°C. Treatments of 45°C for 30 min and >50°C for a minimum of 5 min resulted in 100% mortality of first instars across all six genetic strains as well as eggs, intermediates and adults of phylloxera G4 strain. Insects survived at 22 and 40°C when immersed for 5 and 30 min and 45°C for 5 min and subsequently developed into egg laying adults.
Conclusions Hot water immersion for grapevine root material, as currently recommended in the National Phylloxera Management Protocols is effective for disinfestation of genetically diverse phylloxera and developmental stages. A lower temperature treatment of 45°C for 30 min was 100% effective across diverse strains and developmental stages.
Significance of the Study Immersion duration and water temperature are important considerations for effective disinfestation of grapevine material against genetically diverse phylloxera strains and different developmental stages.
