Abstract
Citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is an important insect pest of citrus and larval feeding exposes leaf cuticle to the causal pathogen of citrus canker disease, the bacterium Xanthomonas axonopodis. The objective of this study was to investigate the CLM infestation in ten citrus cultivars and relationship of its larval density with leaf morphological characters and mineral contents. CLM infestation ranged from 60 to 83% on the tested cultivars except Salustiana, Musambi and seedless Lemon with infestation rates of 44%, 18%, and 17%, respectively, during Summer-2015. Infestation rates in fall 2015 ranged from 60 to 90% except Salustiana, seedless Lemon, and Musambi experiencing low infestation. Similar trends in infestation were observed during Summer-2016. However, the least infested cultivars during all three seasons were Musambi and seedless Lemon. Kinnow, Fairchild, seedless Kinnow and Grapefruit had the most larvae. Relationship between CLM larval density and leaf morphological characters and mineral contents of cultivars was not significant (P > 0.05). Overall, it appears that Fairchild, Grapefruit, and Kinnow mandarins were more susceptible to CLM infestation than seedless Lemon and Musambi. The varieties experiencing lower infestation levels may be more suitable for regions where canker disease and CLM are established and provide source for further investigation to find resistant or tolerant plants, which may help in reducing the use of chemicals.
•Grapefruit, Fairchild and Kinnow were most susceptible to CLM infestation whereas seedless Lemon and Musambi were least susceptible.•Relationship between CLM larval density and leaf morphological characters or trace elements of different cultivars was not significant.•The varieties experiencing lower infestation levels may be more suitable for regions where canker disease and CLM are established.