Evaluation of Host Plant Preferred by Asian Citrus Psyllid – Diaphorina citri

Huanglongbing, also known as citrus greening, is a serious disease affecting citrus crops in Bhutan, leading to a decline in yield. The Asian citrus psyllid (Diaphorina citri) serves as the vector for this disease. A Completely Randomized Design (CRD) experiment was conducted with four treatments and three replications to assess the effectiveness of various alternate host plants in attracting the psyllid. The experiment involved a choice test with four host plants: Murraya paniculata (orange jessamine), Murraya koenigii (curry leaf plant), Citrus aurantifolia (Himalayan lime), and Citrus reticulata (mandarin). For each treatment, the numbers of eggs, nymphs, and adults were recorded. Data analysis was performed using One-way ANOVA, with significance set at P < .05. It was confirmed that the Asian citrus psyllid oviposits on all four host plants. Notably, the psyllid completed its life cycle the fastest on the curry leaf plant, taking an average of 13.33 days. The highest nymphal mortality was observed in mandarin and Himalayan lime at 41%, whereas the lowest mortality rate occurred when all four host plants were present, at 21%. The curry leaf plant was identified as the most effective at attracting the psyllid, followed by orange jessamine. These two species could be utilized as trap crops for psyllid management in orchard settings.