Towards sustainable management of the Mediterranean fruit fly (Ceratitis capitata) in apple orchard in Bane North of Lebanon

Abstract

The Mediterranean fruit fly (Ceratitis capitata) Wiedmann, is considered one of the most destructive fruit insect pests because of its wide distribution and host range which includes more than 350 host plants. During the past years, the medfly started causing serious damage on apple orchards in high elevation in Lebanon. Our project aims at elucidating the biological characteristics of the medfly at high altitude and the efficacy of the mass trapping as an alternative control method against the medfly. Three orchards of apple were selected in Bane area, North of Lebanon at three altitudinal gradients, 1100masl, 1200 masl and 1300 masl. The monitoring of the medfly in the region was conducted for five consecutive years 2015 to 2020 using McPhail traps, which were installed each year on May 1 and kept all season until no medfly was captured. Mass trapping experiments were conducted in 2017, 2018, 2019 and 2020 using TMA card consisting of a lure mixture of the synergistically acting attractants, ammonium acetate, trimethylamine chloride, and trimethylamine. Different trapping densities were done each year from one trap per tree to 3 traps per tree to one trap every 3-4 trees on Golden Delicious and Red Starking Delicious apple varieties. A comparison between two mass trapping bating lures was also conducted on Gala apple variety in 2019.

Results showed variations in peaks of emergence over years on the three different altitudes. The flight patterns extended between 4 months and 5 months and a half depending on the years. There were no distinct peaks in most of the flight patterns indicating the continuous presence of the flies or the overlapping between generations. Mass trapping results in golden Delicious and Red Starking Delicious indicated a clear preference of the medfly towards the white colored apple varieties since the highest infection rates were recorded in this variety (98.54%). The red apple varieties infection rates ranged between 36.36% and 47.19% in the mass trapping techniques. Gala apple variety turned out to be the least infested since its infection rate did not exceed the 16.77% in the conventionally sprayed orchard and 8.96% in the TMA card mass trapping treated trees. Mass trapping did not prove to be an efficacious method of control of traditional apple varieties Golden Delicious and Red Starking Delicious since the infection rate of apples was similar to conventionally treated apples. In the early maturing apple variety Gala, mass trapping proved to be an efficient method since the rate of infection was reduced by half in comparison with the conventionally treated orchard.