Ammar Daher*⁽¹⁾, Ziad Barbar⁽¹⁾, and Ismail Al-Mohammed⁽²⁾

(1) Al Baath University, Homs, Syria.

(2) Al Furat University, Al Hassakah, Syria.

(*Corresponding author: Ammar Daher. E-Mail: ammardaher88@gmail.com).

                    Received: 8/07/2021                      Accepted: 24/10/2021

Abstract: 

This research aimed to study the population dynamic of Two Spotted Red Spider Mites Tetranychus urticae in a cotton field located at Al Dabbaghia in Al-Hassakah governorate during 2019 and 2020. The density of T. urticae did not differ between 2019 and 2020 (the mean was 0.27±0.03 mites / leaf in 2019 and 0.24 ± 0.03 mites / leaf in 2020). In 2019, the first appearance of T. urticae was on 19 July and its density increased and reached the highest level on 10 August. However, in 2020, the first appearance of T. urticae was on 3 August and its density increased and reached the highest level during second week of October. The results showed also that the highest density of T. urticae was observed in the apical leaves of cotton plants during the two seasons of the study. The highest infection rate by T. urticae was observing during harvest, in the two seasons. Concerning the severity of the injury, the highest degree was observed in 2019 where 16% of the leaves of the mid-level cotton plant showed stippling and reddening.

Keywords: Tetranychus urticae Koch– population dynamic – cotton – Syria.  

Full paper in Arabic: pdf