PRECIBARIAL AND CIBARIAL CHEMOSENSILLA IN THE WHITEFLY, BEMISIA-TABACI (GENNADIUS) (HOMOPTERA, ALEYRODIDAE)

The internal anatomy of the anterior alimentary canal of the whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) B-biotype, was ex amined by light, scanning, and transmission electron microscopy to elu cidate the location and number of precibarial and cibarial gustatory s ensilla. Elucidation of the epipharyngeal organ complex within the pre cibarium revealed 10 precibarial sensilla located proximal to where th e paired maxillary stylers diverge on their retraction. The sensory or gan complex within the cibarium consists of 8 sensilla, 6 on the epiph aryngeal sclerite with 2 found within the hypopharyngeal sclerite. Fin e structure investigation revealed the individual neurons to terminate at sensillar pores, which allow direct contact with passing fluids, t hus supporting a chemosensory function. Ultrastructure of the neurons is similar to that of precibarial and cibarial gustatory chemosensilla found in other piercing-sucking insects. Their importance to whitefly feeding is discussed. Copyright (C) 1996 Elsevier Science Ltd.