June 2006. There is concern about citrus greening or huanglungbin as it is called. In 2003, SPC issued a pest alert about the psyllid vectors of the disease; one at least occurs in Papua New Guinea. If this disease is already present in South East Asia, all the more reason for concern. Should the quarantine departments be paying special attention to citrus and other hosts?
A summary of the hosts in the Pacific was supplied by SPC, and is as follows:
The alternate hosts perhaps of most concern are two common plants in the Pacific that the psyllids feed on, more than on citrus. These are Murraya paniculata (mock orange or orange jasmine) and Bergera koenigii (curry leaf).
The disease is known to infect many commercial Citrus spp., including kumquat, which has just been reassigned from Fortunella. After that, there is informed argument about host status of Murraya paniculata: scientists in Thailand and Indonesia say (verbally?) it is a host, but there is a paper (in Japanese), with an abstract in English, which says that it is not. Others say ‘maybe’.
Psyllid hosts listed by Aubert (1990) that are known to occur in PNG include M. paniculata and Triphasia trifolia (see http://plantnet.rbgsyd.nsw.gov.au/PNGplants) and also B. koenigii (NAQS unpublished data). In addition, certain Clausena spp. and Atalantia spp. are included in the listing of Aubert (1990). Unidentified Atalantia spp. and different Clausena spp. are known to be present in PNG (see http://plantnet.rbgsyd.nsw.gov.au/PNGplants).
The citation is: Aubert B (1990b) Integrated activities for the control of greening and its vector Diaphorina citri Kuwayama in Asia. In Proceedings of the 4th International Asia Pacific Conference on Citrus Rehabilitation (Eds B Aubert, S Tontyaporn, D Buangsuwoon) pp. 133-144 (Chiang Mai, Thailand, 4-10th Feb. 1990).