摘要

Leuronota fagarae Burckhardt (Hemiptera: Psylloidea), an exotic psyllid described from South America, was first observed in 2001 on a citrus relative Zanthoxylum fagara (L.) Sarg. (Sapindales: Rutaceae) in southern Florida. Diaphorina citri Kuwayama (Hemiptera: Psylloidea) is principal vector of the bacteria 'Candidatus Liberibacter spp.' causal agent of huanglongbing (HLB) or citrus greening disease. Both vector and disease are now well established in Florida and also reported throughout the Americas and Asia. The host range of D. citri is limited to citrus and some rutaceous relatives. Additional vectors and host plants could accelerate spread of HLB in citrus and threaten endangered species such as Zanthoxylum coriaceum A. Rich. and Zanthoxylum flavum Vahl. Experiments were conducted to evaluate adult survival, reproduction and nymphal development of psyllids on 3 Citrus and 4 Zanthoxylum species as well as orange jasmine, Murraya paniculata (Syn. M. exotica) (Sapindales: Rutaceae), a common ornamental and preferred host of D. citri. Leuronota fagarae in single male-female pairs at 24 degrees C lived an average 4-47 days, 4-12 fold longer on Zanthoxylum spp. (except Z. flavum) than on citrus. Longevity averaged 42-47 days on Z. coriaceum, Z. clava-herculis and M. paniculata and 17-35 days on Z. fagara. Average longevity on C. sinensis, C. x. paradisi and C. reticulata was 4-8 days. Longevity of D. citri in single pairs on C. sinensis, C. x. paradisi, C. reticulata, Z. fagara, Z. flavum, Z. coriaceum and Z. clava-herculis at 24 degrees C averaged 3-29 days and in cohorts on the hybrid rootstock 'Swingle' citrumelo and Z. fagara at 27 degrees C averaged 52-78 days. Longevities of L. fagarae and D. citri on all hosts appeared to be sufficient to acquire and transmit the causal pathogens. However, L. fagarae reproduced only on Z. fagara and D. citri reproduced only on citrus and M. paniculata, indicating that HLB spread on the inappropriate hosts would be inefficient, because acquisition of the bacteria by nymphs is much more efficient than by adults. Nevertheless, adaptation to hosts presently inappropriate for reproduction could increase over time. Field monitoring of citrus and Zanthoxylum spp. for both psyllid species and HLB is warranted in order to maintain effective plans for vector and disease management. The susceptibility of Zanthoxylum spp. to HLB pathogens and ability of D. citri and L. fagarae to acquire and transmit these pathogens are under investigation.

  • 出版日期2014-12