Abstract:

【Objective】The common whitefly (Hemiptera:Aleyrodidae) species on Osmanthus fragrans were identified, and their morphological characteristics were described in order to provide the scientific basis for prevention and effective control of whiteflies on O. fragrans. 【Method】Whitefly specimens were collected from O. fragrans in different regions of China, and the fourth instar nymphs (pseudopupa, pupal case in taxonomy) of each whitefly species were used for morphological observations. The color, shape, size and aggregation state of whiteflies on host plants were observed, photographed, and measured under an ultra-depth microscope, whilst the ultrastructural characteristics of margin, tracheal pore, caudal, vasiform orifice, operculum, lingual, tubercles, pores and setae were observed with scanning electron microscopy (SEM), and the genus and species were described and identified based on the morphological characteristics of pupal cases of whiteflies. 【Result】Five whitefly species in three genera on O. fragrans were identified. Ecological photographs, slide photographs, SEM photos and line-illustrated morphology of each species are provided with detailed descriptions of morphological characteristics, host plants and geographical distribution of each species. Two species belonging to Aleuroclava were described, i.e., A. aucubae and A. psidii. The pupal case of A. aucubae is black and slightly hexagonal, the surface is covered with waxy secretion, and there is a “Y” tubercle on cephalothorax. The pupal case of A. psidii is pale, subovate and small in size, with four pairs of tubercles on the cephalothorax and one pair of small tubercles on the laterad of the first abdominal segment. The Aleurolobus osmanthi had a black pupal case, subrounded in shape, distinct abdominal segments, and a pair of small depressions on the anterior of each segment. Two species belong to Dialeurodes, i.e., D. citri and D. ouchii, were identified. The pupal case of D. citri is pale yellow, the thoracic pore is inside the margin, with claw-like protuberants on both sides, and the almost closed, vasiform orifice is nearly round. The D. ouchii is light yellow in color, and there are eight black spots with different sizes on the pupal case, which are symmetrically distributed. Based on the results of this study and literature reports, an identification key of 11 species of whiteflies on O. fragrans is provided. 【Conclusion】Detailed morphological characteristics of five whitefly species are described on O. fragrans, and an identification key of 11 common whitefly species is provided. The geographical distributions of five common whitefly species on O. fragrans have been expanding, among which D. citri and A. osmanthi are two seriously damaging whitefly species, so we should be alert to the harm and potential threat of whiteflies to O. fragrans.

Key words: Osmanthus fragrans, whitefly(Hemiptera:Aleyrodidae), pseudopupa, morphological characteristics, identification, key