Persian Journal of Acarology

Abstract The application of non-chemical disinfestation treatment for managing the Tetranychus urticae mite pest was investigated in the laboratory. Gamma-ray irradiation at 0, 100, 200, 300, and 400 Gy was applied to eggs, immature stages, and adults of T. urticae on guava leaves (Psidium guajava). Irradiation of eggs resulted in failed hatchability, eggs′ viability at 100 and 200 Gy was partially reduced and was highly suppressed (7.59%) at 400 Gy. The effect of gamma radiation on mite biological parameters was analyzed using ANOVA. Gamma rays at 300 and 400 Gy caused growth retardation in irradiated nymphs and delayed the emergence of the subsequent developmental stage; this growth delay is likely a physiological response to cellular damage. Mites may redirect energy from rapid development toward DNA repair mechanisms. The longevity of irradiated females was substantially shortened (p < 0.05) by increasing radiation dose rates. At lower doses, the total number of eggs deposited by treated females was greatly decreased, and at 400 Gy, it was highly suppressed. Mites exposed to 300–400 Gy resulted in a significant reduction in fecundity (p < 0.05). When irradiated males and unirradiated females mated, the majority of the resulting progeny (F1 adults) were males. Based on the results, irradiation with a dose of 400 Gy can be an effective sterilization treatment for T. urticae on guava leaves. Our study explored gamma rays as an environmentally friendly technique for controlling two-spotted spider mites. A sterilization dose of 400 Gy, derived from our laboratory study, can be applied subsequently to adult males (T. urticae) on guava leaves. These sterilized males can then be released into the field to mate with wild females, thereby reducing pest populations over time. This method could use gamma rays for field-level pest control.