Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2011
Publication Date: September 8, 2011
Citation: Richardson, M.L., Westbrook, C., Hall, D.G., Stover, E.W., Duan, Y., Lee, R.F. 2011. Abundance of citrus leafminer larvae on citrus and citrus-related germplasm. HortScience. 46(9):1260-1264.
Interpretive Summary: The citrus leafminer is a key pest in most citrus growing regions worldwide and may promote bacterial infection in plants. We planted 87 varieties of citrus and closely related plants in Florida to monitor infestations of the leafminer. Many varieties in the genus Citrus were heavily infested by the leafminer, but some varieties had virtually no leafminers and may prove useful in breeding programs aimed at reducing the abundance of this pest on citrus.
The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a key pest in most citrus growing regions worldwide. Adult citrus leafminers oviposit primarily on young elongating flush of citrus as well as other Rutaceae and some ornamental plants. Larvae feed on the epidermal cell layer of developing leaves and injury to leaves provides a pathway for infection by the bacterium Xanthomonas citri subsp. citri (Hasse), the causal agent of Asiatic citrus canker. In this study we quantified abundance of citrus leafminer larvae on seedlings of 87 seed-source genotypes of citrus and citrus relatives in the field in south Florida to identify those that may be avoided by the leafminer or have resistance to this pest. The 87 genotypes varied in abundance of the leafminer. Fifteen genotypes had a mean abundance of more than six leafminers per flush shoot. All but one of these genotypes were in the Citrus genus. Sixteen genotypes had zero, or nearly zero, leafminers, but none were from the Citrus genus. However, many of these 16 genotypes are from genera closely related to true citrus (subtribe Citrinae) and are sexually compatible with citrus. Two genotypes in the subfamily Toddalioideae and Glycosmis pentaphylla (Retz.) Corr. also had a low abundance of leafminer. Glycosmis pentaphylla also is a poor host for the Asian citrus psyllid, Diaphorina citri Kuwayama, and has biochemical resistance to the citrus weevil, Diaprepes abbreviatus (L.), so this genotype, as well as others identified as poor hosts for the leafminer, may prove useful in breeding programs aimed at reducing the abundance of multiple insect pests on citrus.