PLATE 2.9. WORKER MOUTHPARTS, POSTERIOR VIEW

LEFT Photomontage of the posterior view of the mouthparts. The occipital foramen (top of the field is still occupied by the severed tissues that pass from head to thorax. Flanking the foramen are two posterior tentorial pits. Projecting directly clown from the foramen, in the hollow (fossa of the proboscis) behind the head, are the labium and paired maxillae. The triangular piece immediately below the foramen is the postmentum. The maxillae gape, revealing the long, hairy glossa, which is half clasped by the labial palps. (Compare this micrograph with Plate 1.10, the queen mouthparts.) Lastly, the "shoulders" behind and on either side of the labium (prementum) are the mandibles. The top arrow indicates an area that is further magnified in the top right micrograph, the bottom arrow an area in the bottom right micrograph. The middle arrow points to the apical papilla of the maxillary palp, shown at higher magnification in the center right micrograph. (x 34)

TOP RIGHT Higher magnification of the prementum-mandible sector showing the branched body hairs along with three kinds of trichoid sensilla (lop arrow In left micrograph (x 230)

MIDDLE RIGHT . Apical papilla of the maxillary palp. One slender sensilla is seen near its tip (middle, arrow in the left micrograph). (x 450)

BOTTOM RIGHT Array of spine-tipped cuticular scales (bottom arrow in left micrograph on the interior surface of the maxilla (galeae). On the lateral margin of the maxilla, relatively large socketed hairs (sensilla chaetica) arise at regular intervals. These sensors are known to be mechanoreceptors and chemoreceptors (the latter for sugar and salts). ( x 1,200)