Cibarial sensilla and armature in mosquito adults (Diptera: Culicidae)

Cibaria of 37 species of mosquitoes representing nine genera were examined using light microscopy, and those of Anopheles farauti Laveran, Aedes aegypti (L.) Culiseta inornata (Williston), and Culex declarator Dyar and Knab were studied using scanning electron microscopy. Uniporous, trichoid, and campaniform sensilla were found inside the cibarial pump. Based on force-feeding studies of other workers and external structure of sensilla, it is suggested that some of these sensilla may be chemoreceptors involved in determining acceptability of ingested food, whereas the others may be involved in dispatch of ingested blood into the midgut. Trichoid sensilla probably function as flow receptors. Number of palatal papillae in the cibarium varied between species: some have four, others have six. Generally, number and location of cibarial sensilla are similar between species. Cibarial armature was found in the cibaria of females of Culex, some Anopheles species, and Wyeomyia smithii (Coquillett), and also in both sexes of Opifex fuscus (Hutton). The function of this armature is discussed. Possible use of cibarial sensilla and armature to separate taxonomically difficult species is suggested.