Mazen A. Ateyyat
Journal of Insect Science 6 (40), 1-5, (1 November 2006) https://doi.org/10.1673/031.006.4001
KEYWORDS: burr knot, apple rootstocks M9, M26, MM106
Experiments were conducted in Ash-Shoubak area of Jordan from June 2003 to September 2005 to study the effect of three apple rootstocks on the development of the small red-belted clearwing borer, Synanthedon myopaeformis (Borkh.) (Lepidoptera: Sesiidae), under field conditions. Mondial Gala apple trees grafted on the dwarfing rootstock M9 and the semi-dwarfing rootstock M26 were equally infested, whereas those grafted on MM106 showed significantly lower infestation levels. S. myopaeformis bore into burr knots that develop below a graft union on rootstocks and girdle the tree. There was a significant effect of rootstock on the numbers of burrs present, and the percentage of burr knots infested by S. myopaeformis, with M106 having significantly fewer burrs, and a lower percent infested.