International Center of Insect Physiology and Ecology, Nairobi, Kenya.
Department of Genetics, JC Smuts Building, Stellenbosch University, Stellenbosch, South Africa.
J Econ Entomol. 2020 Aug 13;113(4):1640-1647. doi: 10.1093/jee/toaa113.
Diaphorina citri Kuwayama, also known as the Asian citrus psyllid, is a pest of citrus known for its transmission of Candidatus Liberibacter asiaticus (Ca. L. asiaticus), the causal bacterium of Huanglongbing. The African citrus triozid Trioza erytreae (Del Guercio) (Hemiptera: Triozidae) has been the putative vector of Candidatus Liberibacter africanus (Ca. L. africanus) which causes the African citrus greening disease, until the recent detection of D. citri on the continent. Following reports of D. citri in Kenya and Tanzania, we surveyed citrus plants to establish the presence/absence of D. citri in Ethiopia in citrus-growing regions ranging from 900 to 2,460 m above sea level (masl). Diaphorina citri adults were detected in five of the surveyed sites in Ethiopia. Adult insects encountered were collected using an aspirator and stored in 97% ethanol. The mitochondrial cytochrome oxidase 1 (mt COI) gene of the collected insects was amplified using LepF1/LepR1 primers, and sequences obtained showed low variation, which fell within the acceptable range of species. BLAST was used to query the sequences obtained, and all the sequences linked to D. citri accessions that are available in GenBank. The analysis of the sequences revealed a new haplotype of the species that differs from haplotypes previously reported. Phylogenetic relationships of our samples and other D. citri reference sequences was inferred using the Maximum-likelihood method. Monophyly was observed between the samples and the publicly available sequences from global accessions. This is the first report of the presence of D. citri in Ethiopia.
桔二叉蚜，又称亚洲柑橘木虱，是柑橘的一种害虫，以传播柑橘黄龙病菌（Ca. Liberibacter asiaticus）而闻名，该病菌是黄龙病的致病细菌。非洲柑橘三叶草蜂 Trioza erytreae（Del Guercio）（半翅目：三叶草科）一直被认为是非洲柑橘绿斑病的潜在媒介，这种病是由导致该病的非洲柑橘绿化病菌（Ca. Liberibacter africanus）引起的，直到最近在非洲大陆上发现了桔二叉蚜。在肯尼亚和坦桑尼亚报告桔二叉蚜之后，我们对柑橘植物进行了调查，以确定埃塞俄比亚柑橘种植区（海拔 900 至 2460 米）是否存在桔二叉蚜。在埃塞俄比亚的五个调查点检测到桔二叉蚜成虫。用吸气器收集遇到的成虫，并将其储存在 97%的乙醇中。使用 LepF1/LepR1 引物扩增收集昆虫的线粒体细胞色素氧化酶 1（mt COI）基因，获得的序列显示出低变异性，在可接受的种内变异范围内。使用 BLAST 查询获得的序列，所有序列都与 GenBank 中可用的桔二叉蚜序列相关联。对序列的分析显示，该物种的一个新单倍型与以前报道的单倍型不同。使用最大似然法推断了我们的样本和其他桔二叉蚜参考序列的系统发育关系。我们的样本与来自全球序列的公开序列之间观察到单系性。这是桔二叉蚜在埃塞俄比亚存在的首次报告。
