Gamma Irradiation of the European Chafer. 3. Longevity, Flight Behavior, and Mating Competitiveness of Sterilized Males, with Observations on Reproductive Biology

Adults of Amphimallon majalis (Razoumowsky), were sterilized with gamma irradiation at a dose of 5000 md (5 krad), Males and females treated with 10 krad had average life spans 1.4 days shorter for males and 1.5 days longer for females than averages of 14.9 and 19.2 for normal males and females, respectively. These differences are not significant. Males exposed to 5, 7.5, and 10 krad and released in a 42×20×14-ft screen cage showed no significant difference in flight activities or longevities from normal beetles. Increasing the ratio of sterilized males to a pair of normal beetles reduced total egg production and reduced viable egg production to an even greater extent. Combining 12 irradiated males with 1 normal male and female reduced fertile egg production most during early season.