W. HACHED 1
1Entomology-Acarology Laboratory / Plant Health and Environment Department/ National Agronomic Institute of Tunisia, 43 Charles Nicolle Avenue, Mahrajène City 1082 Tunis/ Carthage University, Tunisia.
2Citrus Technical Center (CTA). 8099 Zaouiet Jedidi- Béni Khalled- BP 318- Nabeul- Tunisia
Abstract - In Tunisian citrus groves, damages caused by thrips (Thysanoptera: Thripidae), were firstly observed in 2008. The symptoms of attack were in the form of silver rings and mottling of the bark, depreciating the fruit appearance and thereby reducing their market value. In order to determine the areas of citrus production (particularly on Thomson oranges) most affected by this new pest, a survey was launched in 2013 in four study biotopes: Cap Bon (12 plots), Morneg (4 plots), El Alia (3 plots) and Boussalem (3 plots) thanks to blue sticky traps. On the other hand, in order to evaluate the effect of trap colors on the attractiveness of thrips, two colors were tested: blue and yellow, in three plots only of each biotope. In addition, a trial was conducted in 4 plots of Cap Bon to test the varietal sensitivity of thrips on Thomson and Maltaise oranges. The results of this study showed the regular presence of thrips in the four study biotopes and that the biotope of Boussalem was the most affected by the presence of this new pest. In addition, the most important generations were recorded around the second half of July 2013 for all biotopes. Besides, the blue traps showed a greater attractiveness for this pest. Concerning the varietal sensitivity of thrips, the catch rate at the sticky traps recorded on Thomson oranges was almost twice that recorded on Maltaise oranges. These different results suggest early identification of new thrips attacks and increased monitoring of the most affected biotopes and the most sensitive varieties to prevent their multiplication.