Emerging Pest Alert

New citrus pathogen described in China

Scientific Name: Cryptosporiopsis citricarpa

Describer: Zhu et al.

Common Name: Citrus target spot

Title: New citrus pathogen described in China


Significance: Defoliation, dieback, and mortality of Satsuma mandarin and kumquat have been noticed in northern China since 2006. Cryptosporiopsis citricarpa is a newly described fungus found infecting citrus plants in China. It infects leaves, petioles, shoots, twigs, branches, and standing trunks of citrus, but does not appear to infect fruit. Infected leaves fall from the trees in early spring (March and April), followed by twig dieback, branch blight, and eventually death of whole trees. In some cases infection has caused substantial economic losses in citrus production (Zhu et al., 2012).

Issues of Concern: Many leaf diseases of citrus have been reported, most of which occur during warm, humid seasons. Citrus target spot was identified in China during cooler months, affecting not just the leaves, but also petioles, shoots, twigs, branches, and standing trunks (Zhu et al., 2012).

Hosts: Rutaceae: Citrus unshiu (Satsuma mandarin), Fortunella margarita (kumquat) (Zhu et al., 2012)

Distribution: Reported only in Chenggu County, Shaanxi Province in China (Zhu et al., 2012)


Zhu, L., Wang, X., Huang, F., Zhang, J., Li, H., Ding, D., and K. D. Hyde. 2012. A Destructive New Disease of Citrus in China Caused by Cryptosporiopsis citricarpa sp. nov. Plant Disease, 96, 804-812.