Deleterious effects of electron beam irradiation on development and reproduction of tomato/potato psyllids, Bactericera cockerelli

The potato/tomato psyllid Bactericera cockerelli causes serious damage to several solanaceous crops by direct feeding and vectoring Candidatus Liberibacter solanacearum,a bacterial pathogen.Electron beam(eBeam)irradiation is an environmentally friendly,chemical-free alternative method that is increasing in use for disinfestation of insect pests.We hypothesize that this irradiation technology will have detrimental effects on potato psyllid and thus impede its disease vectoring.To this end,we explored the effects of eBeam treatment ranging from 50 to 500 Gy on survival,development and reproduction of this pest.Impact on psyllids was apparently dose-dependent.When irradiated at 350 Gy,eggs could not hatch,1st instar nymphs failed to emerge,and although a small portion of irradiated 5th instar nymphs survived,the emerged adults were mostly deformed.Abnormality in eclosed adults suggests harmful effects of eBeam on metamorphosis.Reproduction was seriously impaired when female psyllids were exposed to eBeam at the 5th instar nymphal or young adult stage,presumably due to inability to form oocytes.In addition,reciprocal crosses between irradiated and untreated psyllids indicated that female psyllids were more radiosensitive than males to eBeam.Taken together,these findings indicate that eBeam negatively impacted potato psyllid development and reproduction,which would inevitably compromise its disease transmission capacity.A dose of 350 Gy can be considered as a reference dose for effective control of potato psyllids.