Scanning electron microscopic studies on the tongue of Apis species

Honey bees are a subset of bees which are primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Mattu and Verma (1983, 1984) reported that the tongue forms an important component of the morphometric studies of the Apis species. Electron microscopy is considered today an important tool in elucidating the external morphological details of diverse biological material. The technique of scanning electron microscope is helpful in resolving biosystematics of insect genera. Therefore, during the present investigations, the SEM studies on the tongue of 4 species of honey bees viz., A. dorsata, A. florea, A. cerana and A. mellifera, were undertaken. Worker honey bees were dissected to carefully remove the tongue. These were then fixed in glutaraldehyde. After dehydration stubs were prepared and then placed inside the sputter for gold plating. Sputtered specimens were examined in Jeol JSM -6100 scanning electron microscope. The mouth parts of honey bee are adapted for chewing and lapping. The mandible and labium are of the chewing type. The maxillae and the labium are developed into a series of flattened elongate structures to form a proboscis. Glossa of the labium is greatly elongated and terminates in a flabellum, which forms a flexible tongue. Scanning of tongue components to determine adaptive variations related to native flora are very relevant to honey bee biogeography. The present findings are illuminatory and emphasize advantage of applying and incorporating SEM data for resolving the controversy and confusion which today marks the diversity of honey bees.