Some Effects of Gamma Radiation on the Potato Tuberworm, Gnorimoschema operculella (Lepidoptera: Gelechiidae)1

Abstract

Eggs and newly hatched larvae survived dosages up to 9 kilorads. Immature stages that developed from irradiated eggs suffered retardation of development and reduction in size and weight, and the adult moths that emerged were structurally malformed. Females were in many ways more sensitive to irradiation than were males, and all dosages delivered to the eggs reduced the fecundity of the adults that developed from them. Dosages of 24-96 kr given to mature larvae prevented pupation; lesser dosages caused retardation of pupal development; and adult malformation started with dosages of 6 kr. Again adult fecundity was severely affected. Reduction in fertility of the eggs produced was most evident with females irradiated as 8-day-old pupae, but reduction in egg deposition was shown by those irradiated earlier in the pupal stage. The tendency for adults to be malformed also was more pronounced when early pupal stages were irradiated. Adults exposed to 24 kr shortly after emergence laid sterile eggs and those given 96 kr were sluggish, with all body movements diminished.