Ghanem1*, Z. Alnaser2 and A. Basheer2,3
(1) Second faculty of Agricultural Engineering in Suwayda, Damascus University, Syria; (2) Department of Plant Protection, Faculty of Agricultural Engineering, Damascus University, Syria; (3) Biological Control Studies and Research Center, Faculty of Agriculture Engineering, Damascus University, Syria.
*Email address of the corresponding author: [email protected]
There are many variants of the woolly apple aphid Eriosoma lanigerium reported worldwide. This study aimed to determine the variability among insect colonies collected from Suwayda Governorate, Syria in terms of plant host preference and their sensitivity to chemical pesticides. Individual aphid colonies were collected from yellow and red apple varieties. These colonies were reared on two-year-old seedlings of three apple varieties (Golden Delicious, Top Red and Royal Red). The yellow cultivars were more infested by the woolly apple aphid Eriosoma lanigerium than the red cultivars. This explains the existence of two aphid variants that differ in their infestation severity to the Royal Red variety which recorded the highest infestation rate compared to the other cultivars. In addition, three concentrations (50, 100 and 200 ppm) of four pesticides (acetamiprid, chlorpyrifos ethyl, cypermethrin and summer oil) were applied (3 replicates each) to control the woolly apple aphid. The mortality rate and the corrected mortality rate were calculated using the Abbott equation, and the toxicity linear equation for each pesticide was determined. The LC50 value and the resistance rate (RR) were calculated for each variant to determine their sensitivity to the pesticides used. The results obtained showed that the variant collected from the red varieties was less resistant to pesticides than the varient collected from the yellow variety.
Woolly apple aphid, Eriosoma lanigerium, varient, red apple varieties, yellow apple varieties.
https://doi.org/10.22268/AJPP-001421