Effects of gamma radiation on the Mediterranean flour moth, Ephestia kuehniella Zeller, mature larvae and acceptability of irradiated larvae by Bracon hebetor say females

• Gamma irradiation effects on Ephestia kuehniella mature larvae were examined.
• Pupation was affected at 100 Gy and completely prevented at 350 Gy.
• Irradiation negatively affected development of immatures into adults.
• Sex ratio was also affected by irradiation with more males produced.
• Irradiation had no effect on larval acceptance by the Bracon hebetor parasitoid.

Mediterranean flour moth, Ephestia kuehniella Zeller, mature 5th instars were exposed to gamma radiation dosages ranging from 50 to 350 Gy at 50 Gy increments and the effects on pupation, adult emergence and sex ratio were investigated. In addition, effects of irradiation on the rate of development to pupae and adults and the acceptance of irradiated larvae by Bracon hebetor Say females were examined. Results showed that the radio-sensitivity of E. kuehniella larvae increased with increasing dose. Pupation was significantly affected at 100 Gy and completely prevented at 350 Gy. Adult emergence was only slightly different from pupation; emergence was significantly affected at 100 Gy and completely prevented at 300 Gy. Irradiation also negatively affected the rate of development of larvae to pupae and adults. In addition, irradiation significantly affected male: female ratio; sex ratio was skewed in favour of males, and at 250 Gy all emerged moths were males. Furthermore, irradiation had no adverse effect on the degree of acceptance of mature larvae to parasitization; irradiated insects were as acceptable to B. hebetor females as nonirradiated ones.