Abstract: The common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer, 1989 (Hemiptera: Aphalaridae), is a key pest found in pistachio orchards in Iran. This pest has a high potential for developing resistance to insecticides due to its short life cycle and high reproductive potential. Intensive application of insecticides leads to excessive selection pressure followed by resistance to synthetic insecticides in some psylla populations. In this research, effects of four concentrations of three extensively used insecticides (spirotetramat, acetamiprid, and hexaflumuron) on energy resources (like sugar, lipid, glycogen, and protein contents), energy consumption, and cellular energy allocation were investigated in resistant and susceptible populations of the common pistachio psylla in the Kerman province of Iran. Energy resource contents in the susceptible population (133 331.2 mj/insect) were significantly more than in the resistant population (96 253.5 mj/insect), whereas energy consumption in the resistant population (38 630.4 mj energy/h/insect) was higher than in the susceptible population (31 276.8 mj energy/h/insect). Additionally, cellular energy allocation in the resistant population (2 400.9 mj energy/h/insect) was higher than in the susceptible population (2 126.13 mj energy/h/insect). Therefore, stress (especially toxicants) causes variations in metabolism, which influences the growth and reproduction of the pest.

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