Effect of insecticidal and repellency of extract of Rhazya stricta Decne and Nerium oleander L. on common pistachio psyllid (Aganoscena pistaciae) under laboratory condition

Common pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae), is one of the most important pistachio orchards in Iran. It can cause irreparability damage to pistachio with sever feeding of phloem of leaves and buds. This research carried out to study direct effects of ethanolic extract of eshvarak and oleander on fifth nymphal instar. Bioassay test with direct spry method on nymphs was used to determination of mortality and LC50. Also, repellency percentage of adult insects was calculated with two plant extracts by Talukder and Howse formula. All experiments were done in completely randomized design. Based on the results, LC50 of oleander and eshvarak were 142 and 109 miligram per liter (ppm) respectively. The highest mortality of nymphs in concentration of 750 miligram per liter of oleander extract was 63.81±1.24% and in concentration of 600 miligram per liter of eshvarak extract was 71.62±1.24%. Moreover, the results showed the repellency percent of eshvarak more significantly affect than oleander in all concentrations. Repellency percent of adult psyllids affected in both concentration of 10000 ppm of eshvarak and oleander were 88.75±1.34% and 71.25±1.55 % respectively.