Surveillance strategy for Huanglongbing of citrus in Bahia through Sentinel Routes

Bahia is the second-largest orange producer in Brazil, with production predominantly based on traditional cultivation and management practices. However, this activity faces serious phytosanitary threats, requiring constant attention from agricultural defense authorities and integrated preventive actions.The objective of this study was to monitor the possible invasion of the bacterium Candidatus Liberibacter spp. (CLas) through the collection of the vector insect Diaphorina citri along strategically distributed sentinel routes. Collections were carried out quarterly, and D. citri insects found on citrus plants and orange jasmine (Murraya paniculata) were collected using an entomological aspirator. The material obtained was sent to the Plant Virology Laboratory of Embrapa Cassava and Fruits for molecular analysis using Real-Time PCR (qPCR). Between 2019 and 2022, 7,648 adults were collected along Strategic Routes and 4,180 along Control Routes. All plant tissue samples and 99% of insect samples tested negative. Only two collections of psyllids in Western Bahia tested positive; however, the infection was not confirmed in the second sampling. Thus, Bahia maintains its status as an HLB-free area. Early detection of CLas is essential for phytosanitary surveillance, allowing a rapid and efficient response to eradicate foci and prevent the spread of the devastating disease known as citrus huanglongbing.