X-ray Irradiation-Induced Abnormal Development and DNA Damage in Phthorimaea operculella (Lepidoptera: Gelechiidae)

Abstract

The potato tuber moth, Phthorimaea operculella (Zeller), is a destructive pest of Solanaceous crops. This study investigated the effects of X-ray irradiation on development, DNA damage and recovery in P. operculella. Eggs, larvae (*3rd and 5th), pupae, and adults were irradiated with various doses of X-ray irradiation. Egg hatching was inhibited at 70 Gy, and the pupation and adult emergence of 3rd-instar larvae were inhibited at 150 Gy and 70 Gy, respectively. Some 5th-instar larvae pupated at 150 Gy but failed to emerge as adults at 150 Gy. The adult emergence of pupae that spawned at 150 Gy, but egg hatching of F1 generation was completely inhibited. In addition, the adult emergence of irradiated-pupae was completely inhibited at 200 Gy. Adults spawned at 150 Gy, but the hatching of the F1 generation was completely suppressed. The levels of DNA damage and repair in P. operculella adults were investigated using the alkaline comet assay. The results indicated that X-ray irradiation increased DNA damage in a dose-dependent manner and showed that DNA damage was repaired in a time-dependent manner. However, damage from a high radiation doses was not completely repaired. This result suggests that at least 150 Gy radiation should be used for the control P. operculella.