Morphological Identification and DNA Barcoding Reveal Species Richness and New Expansion of the Whiteflies (Hemiptera: Aleyrodidae) in Egypt

Rapid detection and accurate identification of whiteflies that affecting vegetable, fibre and ornamental crops are essential for preventing or reducing their establishment and spread. Morphological and molecular identification of the present study revealed the presence of four whitefly species viz. Bemisia tabaci , Aleurothrixus floccosus , Aleuroclava psidii and Pealius mori , which were collected from Lantana camara , Citrus spp., Psidium guajava and Morus alba , respectively. Our observations are generally consistent with the diagnostic morphological features of whitefly puparia reported in previous taxonomic studies. Minor deviations, such as those involving chaetotaxy patterns, vasiform orifice or the operculum coverage, represented typical intraspecific variation. Molecular analysis using the mitochondrial cytochrome oxidase subunit I (COXI) gene introduced the genetic characteristics of A. floccosus , A. psidii and P. mori for the first time in Egypt, revealing clear genetic differentiation among the four species, and confirming their close relationship with reference sequences in the NCBI GenBank. The COXI sequences of B. tabaci were clustered with isolates of the same species from Asia, forming a sister clade to B. afer . The ML tree showed that it affiliated with the Q biotype (Mediterranean [MED] group) along with isolates from Asia and the Americas. A. floccosus sequences were clustered with isolates from South America and Israel, a sister clade to A. aepim . A. psidii were clustered with isolate from Israel, close to the Chinese isolates. P. mori were clustered with isolates from China and Israel, forming a sister clade to P. nagerkailensis . Tajima's D and Fu & Li' D values in the case of B. tabaci were negative −0.63 ( p = 0.105302) and −0.37088 ( p < 0.10), respectively, suggesting a genetic divergence consistent with natural evolution. While in the case of the other three species they were found to be 2.40 ( p = 0.3287) and 0.88278 ( p < 0.10), respectively, suggesting a recent population bottleneck effect. The detection of multiple whitefly species coexisting in the same region highlights the need for continuous monitoring and the integration of morphological and molecular approaches to improve identification accuracy and inform pest management strategies.