Aydın Ş. Tunçbilek

Susceptibility of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.), to gamma radiation

Abstract Gamma radiation was applied over the range of 25–125 Gy at five dose levels against 7–10-day-old adults of Oryzaephilus surinamensis , and the sterility and mortality effects were investigated. All experiments were carried out in incubators maintained at 27 ± 0.5 °C and 70 ± 5% relative humidity. The results obtained revealed that the percentage of adults surviving was dependent on the dose level. There were no beetles left alive and no progeny produced when adults were exposed to 125 Gy. LD 50 and LD 99.9 values were determined to be 55.6 and 216.4 Gy respectively; the sterilizing dose levels (SD 50 and SD 99.9 ) were estimated to be 26.2 and 117.1 Gy respectively.

The influence of rearing medium on the irradiation sensitivity of eggs and larvae of the flour beetle, Tribolium confusum J. du Val

Abstract In this study, gamma radiation was applied at six dose levels over the range of 5–40 Gy for 0–2-day-old eggs, and at eight dose levels between 10–80 Gy for 16–18-day-old larvae of Tribolium confusum. Sterility, mortality and other effects of gamma radiation were investigated. All experiments were performed in incubators maintained at 27 ± 0.5 °C and 70 ± 5% r.h. The development of adults reared on different flours from irradiated eggs and larvae was prevented by exposure to 40 and 50 Gy of gamma radiation, respectively. Rate of development of these stages on different flours and the yield of adults was influenced by rearing medium. Rapidly developing flour beetles are more susceptible to killing by gamma radiation. For each stage reared on different media (wheat, barley and maize flours), LD50 and LD99.9 values were determined, together with sterilizing dose levels (SD50 and SD99.9).