Lower levels of enzyme activity increase the susceptibility of Agonoscena pistaciae to imidacloprid

Hamzeh Izadi (PhD)^1,2, Marjan Bemani (PhD)¹ Mehrnoush Mehrabian (MD)²

¹ Division of Plant Protection, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran

² Pistachio Safety Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran

Received: 16.07.2023  Accepted: 29.10.2023

Abstract

Background: The common pistachio psyllid, Agonoscena pistaciae (Hemiptera: Aphalaridae), is a major pest in pistachio farming areas across Iran. Nymphs and adult insects feed on the plant sap by inserting their mouthparts into the leaves. This feeding behavior results in a decrease in both the quality and quantity of the pistachio crop.

Materials and methods:  The sensitivity of 5^th instar nymphs of A. pistaciae in Rafsanjan to commonly used insecticides imidacloprid, chlorpyrifos, and fenvalerate, was examined using the tower spraying method.

Results: Based on the results, the psyllid exhibited LC₅₀ values of 41.6, 372.4, and 256.8 ml a.i./L for imidacloprid, chlorpyrifos, and fenvalerate, respectively. According to the results of this study, A. pistaciae was significantly more sensitive to imidacloprid than to two other insecticides, chlorpyrifos and fenvalerate. The study measured the impact of pesticides on the activity of three key detoxification enzymes - cytochrome P₄₅₀ enzymes, naphthyl acetate esterase enzymes, and glutathione S-transferases. The results showed that nymphs treated with imidacloprid had the lowest enzyme activity.

Conclusion: The findings suggest that imidacloprid is more effective in controlling the common pistachio psylla due to its lower detoxification under the enzyme activity.

Izadi H, Bemani M, Mehrabian M. Lower levels of enzyme activity increase the susceptibility of Agonoscena pistaciae to imidacloprid. Pistachio and Health Journal. 2023;6(3-4):31-42.