The use of Murraya koenigii as trap crop for the management of the psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) and its effect on incidence of Huanglongbing (HLB) in citrus orchards

Abstract

Currently, the control of the disease Huanglongbing (HLB) or "Greening" is based mainly on chemical control of the vector insect Diaphorina citri, accomplished through intensive applications of chemicals, which have caused outbreaks of secondary pests and the elimination of natural enemies. This study aims to evaluate the possibility of using curry (Murraya koenigii) as trap crop for the management of psyllid D. citri. For that purpose, first, we will carry out a transmission test of the bacterium "Candidatus Liberibacter sp." to determine if the curry plant is not a host of the bacterium. Subsequently, we will carry out: 1) selection of systemic insecticides for the use in curry plants determining the residual period and efficiency; 2) free choice test to verify the host preference for feeding and oviposition of D. citri in curry plants with and without sprouting and in relation to citrus; 3) test with trap crop, in which curry plants will be installed in a citrus plot where the rows of orange will end in a hedge. Along the plot, we will place yellow sticky traps to sample the number of psyllids occurring in the area. In the middle of the curry plant crown, we will place a transparent acrylic plate containing glue, to verify the attractiveness of this plant. In addition, according to frequency of inspection carried out in the plot, we will determine the incidence of plants with HLB symptoms during the experiment. Subsequently, we determine the spatial distribution of plants with HLB symptoms and psyllid. (AU)