ARI REVIEW FOR 2016-2017

Application of insecticides was based on: a) RPW’s population density in the area; b) pheromone trap captures; and c) the intensiveness and frequency of palm damage in the area. Targeted insecticide applications on the selected palms were performed as follows: 1) curative applications: palms with visible signs of damage on leaves and leaves’ bases, or palms with sloped leaves or with damaged but not dried central “heart” leaves; 2) preventive applications: palms with no macroscopically visible signs of damage. In both cases, no other control measures had been applied on the selected palm trees prior to or during this study. The two-year results showed that, 8 out of 21 (38.1%) date palms of the P. dactylifera species with visible signs of severe damage at the beginning of applications couldn’t recover and finally died, while 2 (9.5%) palms managed to recover from slight damage. Eleven (52.4%) palms without any visible signs of damage remained healthy throughout the study. On the other hand, 4 out 10 (40.0%) P. canariensis palms with or without visible signs of damage at the beginning of applications were totally destroyed by the pest during the 1 st year of applications. Visible signs of damage appeared on the other 6 palms during the 2 nd year of treatments and eventually these palms were not able to recover and died, indicating once again the preference of the pest to this palm species. The most frequent problem faced using the trunk injection method was the clogging of pegs with gum mainly on date palms, as a result of the injuries caused by gallery drilling of the trunk, preventing this way the insecticide flow within the trunk. ( V. Vassiliou ) Molecular diagnostics for detecting pyrethroid and abamectin resistance mutations in Tetranychus urticae Avermectin and pyrethroid resistance mutations (the G314D and the G326E in the glutamate gated chloride channels, and the F1538I in the voltage gated sodium channel) have been reported in the spider mite Tetranychus urticae , one of the most devastating pests of protected and open field crops worldwide. We developed three TaqMan molecular diagnostic assays for monitoring the presence and frequency of these mutations in T. urticae field populations. The TaqMan assays were validated against known genotypes and subsequently used to monitor the frequency of the resistance mutations in eleven T. urticae populations from Greece and Cyprus, with variable history of avermectin and pyrethroids applications. The frequency of the F1538I pyrethroid resistance mutation largely varied among samples, with highest frequencies (75%–97%) detected in four populations derived from protected and open field crops from Crete and Peloponnesus, low frequencies in three populations (2.5%–11%) from Attiki, Cyprus and Crete and not detected in four populations from Crete, Peloponnesus and Cyprus. The frequency of the abamectin resistance mutations G314D and G326E also varied across populations (from 0 to 100%), showing fixation in two populations (N97.5% for the G314D and 100% for the G326E), originating from rose greenhouses from Greece, low frequencies in three populations (5%–12.5%) also originating from rose greenhouses (Crete, Peloponnesus and Cyprus) and not detected in six populations from protected and open field vegetable crops. The TaqMan diagnostics showed higher resolution in detecting specific alleles in low frequency, compared to massive quantitative sequencing approaches previously employed. They can be used, together with classical bioassays, to support evidence - based insecticide resistance management strategies ( V. Vassiliou ) 49 Plant Protection Application of an insecticide using plastic pegs inserted in date palm trunk