First, second, and fourth authors: Department of Entomology and Acarology, 'Luiz de Queiroz' College of Agriculture, University of São Paulo, C.P. 9, Piracicaba, SP, 13.418-900, Brazil; and third author: Centro de Citricultura Sylvio Moreira, IAC, C.P. 4, Cordeirópolis, SP, 13490-970, Brazil.
Phytopathology. 2018 Sep;108(9):1089-1094. doi: 10.1094/PHYTO-01-18-0012-R. Epub 2018 Jul 2.
The Asian citrus psyllid (ACP) Diaphorina citri, vector of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of citrus Huanglongbing (HLB), is controlled by application of insecticides, which, although effective, has resulted in serious biological imbalances. New management tools are needed, and the technique known as "trap crop" has been attracting attention. A potential plant for use as a trap crop in the management of the ACP is Murraya koenigii (curry leaf). However, for this plant to be used in the field, it needs to be attractive for the vector and must not harbor CLas. To verify the potential of curry leaf as trap crop for the management of HLB, we investigated the ability of D. citri to transmit CLas to M. koenigii, and to other test plants, including M. paniculata (orange jasmine) and cultivar Valencia sweet-orange seedlings. For the tests, the insects were reared on a symptomatic CLas-infected plant and allowed to feed on the three test plant species. The overall maximum transmission rate for the citrus seedlings was 83.3%, and for orange jasmine was 33.3%. Successful transmission of CLas by ACP to the curry-leaf seedlings was not observed, and it was treated as immune to CLas. Supported by the previous results that M. koenigii is attractive for ACP, these results indicate that curry leaf is an excellent candidate for use as a trap crop, to improve the management of the insect vector and consequently of HLB.
柑橘木虱（ACP）Diaphorina citri 是“亚洲韧皮部杆菌（CLas）”的载体，而 CLas 被认为是柑橘黄龙病（HLB）的致病因子。该木虱通过使用杀虫剂进行防治，虽然有效，但却导致了严重的生物失衡。因此，需要新的管理工具，而被称为“诱集作物”的技术引起了人们的关注。作为 ACP 管理中诱集作物的潜在植物是芸香科植物九里香（Murraya koenigii，也被称为咖喱叶）。然而，为了使这种植物能够在田间使用，它需要对该木虱具有吸引力，并且不能携带 CLas。为了验证咖喱叶作为管理 HLB 的诱集作物的潜力，我们研究了柑橘木虱将 CLas 传播给九里香以及其他测试植物（包括芸香科植物橙茉莉（Murraya paniculata）和瓦伦西亚甜橙实生苗）的能力。在测试中，昆虫在感染 CLas 的症状明显的植物上饲养，并允许它们取食三种测试植物。柑橘实生苗的总最大传播率为 83.3%，而橙茉莉的最大传播率为 33.3%。未观察到 ACP 成功地将 CLas 传播到咖喱叶苗上，因此认为其对 CLas 具有免疫性。这些结果与之前九里香对柑橘木虱具有吸引力的结果相吻合，表明咖喱叶是作为诱集作物的极好候选植物，可改善对该昆虫媒介的管理，从而改善 HLB 的管理。
