Invasion of Bondar's Nesting Whitefly (Paraleyrodes bondari Peracchi) in coconut: The first record of a new whitefly species from Sri Lanka

Abstract

Since the first report in 2019, several whitefly species have invaded coconut plantations in Sri Lanka. Until now, the presence of Aleurodicus rugioperculatus Martin, Paraleyrodes minei Iaccarino, Aleurotrachelus atratus Hempel and Aleurodicus dispersus Russell have been confirmed through morphological and molecular characterization. Another whitefly species was recently observed in Sri Lankan coconut plantations during the continuous field inspections. Hence, the present study was conducted to characterize this new species. During the random field surveys conducted in Gampaha district, whitefly-infested coconut leaflets (n= 20) were randomly collected. Morphologically similar adults with unique ‘X’ shaped oblique greyish bands on wings were collected from characteristic wooly wax nests. These adults were then examined under the stereomicroscope and used for total genomic DNA isolation using the Cetyltrimethylammonium Bromide (CTAB) method. Subsequently, the extracted DNA samples were subjected to PCR targeting a specific region of mitochondrial gene cytochrome c oxidase subunit I (mtCOI) using universal primers: LCO 1490 and HCO 2198. The resulting PCR products were subjected to 1% agarose gel electrophoresis under 90 V for 01 hour. PCR products of the expected band size 675 bp were observed. One clear DNA band resulting from PCR amplification was subjected to bidirectional Sanger sequencing at Macrogen, Republic of Korea. Analysis of the resulting sequences using BioEdit software and a BLASTn similarity search confirmed the presence of Paraleyrodes bondari with 99-100% sequence similarity to known samples in the National Center for Biotechnology Information (NCBI) database. Therefore, the study confirms the presence of Bondar’s Nesting Whitefly (BNW), a neotropical whitefly species; P. bondari. Emerging non-native whitefly species like P. bondari and its polyphagous nature may pose a threat to the Sri Lankan coconut industry in the future.