Host specificity testing and examination for plant pathogens reveals that the gall-inducing psyllid Calophya latiforceps is safe to release for biological control of Brazilian peppertree

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), is one of the worst upland exotic weeds in Florida, USA. Foreign exploration for natural enemies led to the discovery of a pit-galling psyllid, Calophya latiforceps Burckhardt (Hemiptera: Calophyidae), in the state of Bahia, Brazil, in 2010. Crawlers of C.latiforceps stimulate the formation of galls on the leaves of S.terebinthifolia resulting in leaf discoloration and in some cases leaf abscission. To determine whether C.latiforceps is a safe candidate for biological control of S.terebinthifolia, host specificity and the presence of selected plant pathogens were examined. Adult oviposition, gall formation, and adult survival of C.latiforceps were examined on 89 plant species under no-choice and choice conditions. We found that C.latiforceps laid eggs on plants in seven families; however, crawlers stimulated gall formation and completed development to adult only on S.terebinthifolia. All crawlers on non-target plants died, likely due to starvation caused either by the absence of a feeding stimulus or by a hypersensitive plant response. Under no-choice conditions, 10% of adults lived for 19days on the target weed, but adult survival was reduced to <3days on non-target plants. Choice testing revealed that females preferred to oviposit on S.terebinthifolia compared to non-target plants. Molecular methods and indicator host inoculations did not detect the presence of Candidatus Liberibacter solanacearum', Ca.L. asiaticus', Ca.L. americanus', Ca.L. africanus', or plant viruses in adult C.latiforceps. We conclude that releasing C.latiforceps in the USA will have extremely low risk to non-target plants, and provides another tool for the management of S.terebinthifolia.