Physiological and behavioral bioassays to evaluate the potential use of the Sterile Insect Technique to control Bagrada hilaris (Hemiptera:Pentatomidae)

The polyphagous Pentatomidae Bagrada hilaris, native to East Africa and the Middle East, has recently spread to the South Western part of the US, South America and two islands in the Mediterranean basin: Malta and Pantelleria (Southern Italy). The present work aims to evaluate the potential application of SIT as a biocontrol technique for the Pantelleria population of this pest. In order to assess the suitability of a SIT strategy, it is important to investigate the effects of irradiation on the biology of the insect and aspects related to its reproduction. The study focused on the possible presence of Last Mating Sperm Precedence (i. e., whether the female uses only the sperm of the last male with whom she mated) and the main differences between irradiated and non-irradiated individuals in sexual behavior. For these experiments, newly emerged individuals were irradiated at different doses. The results showed that acceptable sterility for SIT application is achieved from 60 Gy. In addition, the release of only irradiated males seems to be more suitable. No Last Mating Sperm Precedence mechanism was detected at the doses of 60, 80 and 100 Gy. The study of sexual behaviour showed in the no choice experiment showed significant differences in the total time taken to mate