Curry leaf smells better than citrus to females of Diaphorina citri (Hemiptera: Liviidae)

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama has a host range of about 20 species of the family Rutaceae, including Citrus spp. However, few studies have reported on its host preference. This study evaluated the host-choice behavior of ACP in curry leaf (Murraya koenigii L.), through free-choice test and bioassays with a type 'Y' olfactometer, and also characterized the volatiles involved in attracting the ACP. In the free-choice test, the number of adults per plant on curry leaf was higher than the number on citrus plants. When the ACP was tested in the olfactometer, the females showed preference for curry leaf over citrus plants. Sixteen volatile compounds were identified in citrus and curry leaves. Qualitative and quantitative differences in the compounds released by citrus and curry leaves were determined. The volatiles present in these hosts may play an important role in the attraction of D. citri. With this information, further studies should be done to develop new management strategies for the ACP.