D. Stefanova*, S. Malchev

Fruit Growing Institute, 12 Ostromila Str., 4004 Plovdiv, Bulgaria

(Manuscript received 7 July 2020; accepted for publication 11 August 2020)

Abstract. One of the main insect pests of the cherry trees in Bulgaria is Myzus cerasi (Homoptera, Aphididae). The black cherry aphids occur annually in orchards and cause yield loss or degraded quality. In 2018 and 2019, resistance to Myzus cerasi was assessed on 11 selected sweet cherry genotypes in a breeding orchard at the Fruit Growing Institute – Plovdiv. Susceptibility to aphid infestation was assessed through inspection of 100 leaf rosettes from individual tree hybrids. Some of the studied genotypes 6-132, 6-132 (1), 6-131, and 6-131 (1) were not infested by black cherry aphids in the two years of this research. Aphid colonies were observed on all other studied trees from the selected hybrids. The study is still ongoing.